{"id":7306,"date":"2026-09-09T08:20:25","date_gmt":"2026-09-09T07:20:25","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/"},"modified":"2026-09-24T11:05:13","modified_gmt":"2026-09-24T10:05:13","slug":"processing-waste-polymers","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/","title":{"rendered":"Processing Waste Polymers"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-polymer-waste-page\">\n  <style>\n    .ols-revision-page {\n      --navy: #1C244B;\n      --blue: #2563eb;\n      --soft-blue: #eef4ff;\n      --soft-red: #fff7f7;\n      --soft-purple: #f7f0ff;\n      --soft-green: #f0f7f1;\n      --grey-text: #667085;\n      --body-text: #1f2937;\n      --border: rgba(28, 36, 75, 0.14);\n      --shadow: 0 18px 45px rgba(28, 36, 75, 0.10);\n      --inner-shadow: 0 10px 26px rgba(28, 36, 75, 0.08);\n      font-family: Poppins, Arial, sans-serif;\n      color: var(--navy);\n      background: #ffffff;\n    }\n    .ols-revision-page * { box-sizing: border-box; }\n    .ols-main { min-width: 0; max-width: 970px; }\n    .ols-breadcrumbs { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 22px; font-size: 15px; color: var(--grey-text); }\n    .ols-breadcrumbs a, .ols-breadcrumbs span { color: var(--grey-text); text-decoration: none; font-weight: 600; }\n    .ols-breadcrumbs a:hover { color: var(--blue); text-decoration: underline; text-underline-offset: 3px; }\n\n    .ols-title-card, .ols-note-card, .ols-h5p-card, .ols-related-card {\n      background: #ffffff; border: 1px solid var(--border); border-radius: 28px; box-shadow: var(--shadow);\n      padding: 34px; margin-bottom: 24px; overflow: hidden;\n    }\n    .ols-title-card { background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%); }\n    .ols-title-card h1 { margin: 0 0 18px; font-size: clamp(36px, 5vw, 58px); line-height: 1.08; font-weight: 800; letter-spacing: -0.04em; color: #111827; }\n    .ols-page-intro { font-size: 19px; line-height: 1.7; font-weight: 300; color: var(--body-text); margin: 0 0 22px; }\n    .ols-badges { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 22px; }\n    .ols-badge { display: inline-flex; align-items: center; padding: 9px 14px; border-radius: 999px; background: #ffffff; border: 1px solid var(--border); font-size: 15px; font-weight: 600; color: var(--navy); }\n\n    .ols-note-card.soft { background: linear-gradient(135deg, #ffffff 0%, var(--soft-red) 100%); }\n    .ols-note-card.purple { background: linear-gradient(135deg, #ffffff 0%, var(--soft-purple) 100%); }\n    .ols-note-card.green { background: linear-gradient(135deg, #ffffff 0%, var(--soft-green) 100%); }\n    .ols-note-title { display: flex; align-items: center; gap: 14px; margin-bottom: 20px; }\n    .ols-note-icon { width: 52px; height: 52px; border-radius: 16px; background: var(--navy); color: #ffffff; display: grid; place-items: center; font-size: 24px; font-weight: 800; flex-shrink: 0; }\n    .ols-note-title h2, .ols-h5p-card h2, .ols-related-card h2 { margin: 0; font-size: clamp(28px, 3.5vw, 42px); line-height: 1.15; font-weight: 800; color: #111827; letter-spacing: -0.03em; }\n    .ols-h5p-card h2, .ols-related-card h2 { margin-bottom: 14px; }\n    .ols-note-card p, .ols-note-card li { font-size: clamp(15px, 1.25vw, 17px); line-height: 1.65; font-weight: 300; color: var(--body-text); }\n    .ols-h5p-card p, .ols-related-card p { font-size: clamp(15px, 1.3vw, 18px); line-height: 1.65; font-weight: 300; color: var(--body-text); }\n    .ols-note-card strong, .ols-h5p-card strong, .ols-related-card strong { font-weight: 700; color: var(--navy); }\n    .ols-note-card ul, .ols-note-card ol { margin: 0; padding-left: 22px; }\n\n    .ols-key-box { margin-top: 20px; background: var(--soft-green); border: 1px solid rgba(63, 143, 70, 0.25); border-radius: 20px; padding: 18px 20px; }\n    .ols-key-box p { margin: 0; font-weight: 400; color: var(--navy); }\n    .ols-equation-box { margin-top: 20px; background: #ffffff; border: 1px solid var(--border); border-left: 5px solid var(--blue); border-radius: 18px; padding: 18px 20px; box-shadow: var(--inner-shadow); }\n    .ols-equation-box p { margin: 0; font-size: clamp(18px, 2vw, 24px); line-height: 1.5; font-weight: 700; color: var(--navy); }\n\n\n    .ols-table-wrap { overflow: hidden; width: 100%; border-radius: 22px; border: 1px solid var(--border); background: #ffffff; margin-top: 18px; }\n    .ols-table { width: 100%; max-width: 100%; border-collapse: collapse; table-layout: fixed; }\n    .ols-table th { background: var(--navy); color: #ffffff; padding: 16px; text-align: left; font-size: clamp(13px, 1.05vw, 16px); line-height: 1.45; font-weight: 600; overflow-wrap: anywhere; word-break: normal; hyphens: auto; }\n    .ols-table td { padding: 16px; border-bottom: 1px solid var(--border); font-size: clamp(13px, 1vw, 16px); line-height: 1.5; color: var(--body-text); vertical-align: top; overflow-wrap: anywhere; word-break: normal; hyphens: auto; }\n    .ols-table tr:last-child td { border-bottom: none; }\n\n    .ols-mini-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-top: 22px; }\n    .ols-mini-box { background: #ffffff; border: 1px solid var(--border); border-radius: 20px; padding: 18px; box-shadow: var(--inner-shadow); }\n    .ols-mini-box h3 { margin: 0 0 8px; color: var(--navy); font-size: 21px; line-height: 1.25; font-weight: 800; }\n    .ols-mini-box p { margin: 0; font-size: 15px; line-height: 1.55; color: var(--body-text); }\n\n    .ols-h5p-card { background: linear-gradient(135deg, #ffffff 0%, #f7f0ff 100%); }\n    .ols-h5p-frame { margin-top: 22px; padding: 18px; border-radius: 24px; background: #ffffff; border: 1px solid var(--border); box-shadow: inset 0 0 0 1px rgba(28, 36, 75, 0.03); }\n\n\n    .ols-related-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; margin-top: 18px; }\n    .ols-related-item { border: 1px solid var(--border); border-radius: 18px; padding: 18px; background: #ffffff; color: var(--navy); text-decoration: none; font-weight: 600; line-height: 1.5; transition: transform 0.2s ease, box-shadow 0.2s ease; }\n    .ols-related-item:hover { transform: translateY(-2px); box-shadow: 0 10px 22px rgba(28, 36, 75, 0.08); }\n\n    @media (max-width: 1050px) {\n      .ols-main { max-width: none; }\n      .ols-mini-grid, .ols-related-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }\n    }\n    @media (max-width: 900px) {\n    }\n    @media (max-width: 760px) {\n      .ols-title-card, .ols-note-card, .ols-h5p-card, .ols-related-card { padding: 24px 18px; border-radius: 22px; }\n      .ols-note-title { align-items: flex-start; }\n      .ols-topic-list, .ols-mini-grid, .ols-related-grid { grid-template-columns: 1fr; }\n      .ols-polymer-waste-page .ols-table-wrap { overflow: hidden; border-radius: 20px; }\n      .ols-polymer-waste-page .ols-table,\n      .ols-polymer-waste-page .ols-table thead,\n      .ols-polymer-waste-page .ols-table tbody,\n      .ols-polymer-waste-page .ols-table th,\n      .ols-polymer-waste-page .ols-table td,\n      .ols-polymer-waste-page .ols-table tr { display: block; width: 100%; }\n      .ols-polymer-waste-page .ols-table thead { display: none; }\n      .ols-polymer-waste-page .ols-table tr { background: #ffffff; border-bottom: 1px solid var(--border); padding: 14px; }\n      .ols-polymer-waste-page .ols-table tr:last-child { border-bottom: none; }\n      .ols-polymer-waste-page .ols-table td { display: grid; grid-template-columns: minmax(110px, 0.42fr) minmax(0, 1fr); gap: 12px; align-items: start; padding: 12px 0; border-bottom: 1px solid rgba(28, 36, 75, 0.10); font-size: 14px; line-height: 1.55; }\n      .ols-polymer-waste-page .ols-table td:last-child { border-bottom: none; }\n      .ols-polymer-waste-page .ols-table td::before { font-weight: 800; color: var(--navy); line-height: 1.45; }\n      .ols-polymer-waste-page .ols-table td:nth-child(1)::before { content: \"Method\"; }\n      .ols-polymer-waste-page .ols-table td:nth-child(2)::before { content: \"Main advantage\"; }\n      .ols-polymer-waste-page .ols-table td:nth-child(3)::before { content: \"Main disadvantage\"; }\n      .ols-polymer-waste-page .ols-table td:nth-child(4)::before { content: \"Exam detail\"; }\n    }\n    @media (max-width: 420px) {\n      .ols-polymer-waste-page .ols-table td { grid-template-columns: 1fr; gap: 6px; }\n    }\n    .ols-author {\n      display: flex;\n      align-items: center;\n      gap: 20px;\n      padding: 28px;\n      border-radius: 28px;\n      background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid rgba(28, 36, 75, 0.12);\n      box-shadow: 0 18px 45px rgba(28, 36, 75, 0.10);\n      margin-top: 22px;\n    }\n    .ols-author-avatar-img {\n      width: 92px;\n      height: 92px;\n      border-radius: 50%;\n      object-fit: cover;\n      object-position: center;\n      flex-shrink: 0;\n      border: 4px solid #ffffff;\n      box-shadow: 0 14px 32px rgba(28, 36, 75, 0.18), 0 0 0 1px rgba(28, 36, 75, 0.10);\n      transition: transform 0.25s ease, box-shadow 0.25s ease;\n    }\n    .ols-author:hover .ols-author-avatar-img {\n      transform: scale(1.04);\n      box-shadow: 0 20px 42px rgba(28, 36, 75, 0.22), 0 0 0 1px rgba(28, 36, 75, 0.10);\n    }\n    .ols-author-content { min-width: 0; }\n    .ols-author-title {\n      margin: 0 0 4px;\n      font-size: clamp(24px, 3vw, 34px);\n      line-height: 1.15;\n      font-weight: 700;\n      color: var(--navy);\n      letter-spacing: -0.03em;\n    }\n    .ols-author-description {\n      margin: 0;\n      font-size: 17px;\n      line-height: 1.7;\n      font-weight: 300;\n      color: var(--grey-text);\n    }\n    .ols-linkedin-pill {\n      display: inline-flex;\n      align-items: center;\n      justify-content: center;\n      gap: 10px;\n      margin-top: 16px;\n      padding: 11px 18px;\n      border-radius: 999px;\n      background: linear-gradient(135deg, #0A66C2, #004182);\n      color: #ffffff;\n      text-decoration: none;\n      font-size: 14px;\n      line-height: 1;\n      font-weight: 700;\n      letter-spacing: 0.01em;\n      box-shadow: 0 10px 22px rgba(10, 102, 194, 0.24);\n      position: relative;\n      overflow: hidden;\n      transition: transform 0.22s ease, box-shadow 0.22s ease;\n    }\n    .ols-linkedin-pill:hover {\n      transform: translateY(-3px) scale(1.03);\n      box-shadow: 0 16px 34px rgba(10, 102, 194, 0.34), 0 0 0 6px rgba(10, 102, 194, 0.10);\n    }\n    .ols-linkedin-icon { width: 18px; height: 18px; display: block; flex-shrink: 0; }\n    .ols-attribution-card {\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n      border: 1px solid rgba(28, 36, 75, 0.14);\n      border-radius: 28px;\n      box-shadow: 0 18px 45px rgba(28, 36, 75, 0.10);\n      padding: 34px;\n      margin-bottom: 24px;\n      overflow: hidden;\n      box-sizing: border-box;\n    }\n    .ols-attribution-card p {\n      margin: 0;\n      font-size: 14px;\n      line-height: 1.65;\n      font-weight: 300;\n      color: #667085;\n    }\n    .ols-attribution-card strong { font-weight: 700; color: #1C244B; }\n\n    \/* Non-clipping image hover zoom and click-to-fullscreen lightbox *\/\n    .ols-revision-page,\n    .ols-revision-page .ols-main,\n    .ols-revision-page .ols-note-card,\n    .ols-revision-page .ols-title-card,\n    .ols-revision-page .ols-h5p-card,\n    .ols-revision-page .ols-related-card,\n    .ols-revision-page .ols-zoom-card,\n    .ols-revision-page .ols-zoom-card-image {\n      overflow: visible;\n    }\n\n    .ols-zoom-card {\n      position: relative;\n      z-index: 1;\n      margin: 26px 0 4px;\n      border: 1px solid var(--border);\n      border-radius: 26px;\n      background: #ffffff;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-zoom-card:hover { z-index: 40; }\n\n    .ols-zoom-card-image {\n      position: relative;\n      width: 100%;\n      min-height: 330px;\n      display: flex;\n      align-items: center;\n      justify-content: center;\n      background: #ffffff;\n      padding: 20px;\n      border-bottom: 1px solid var(--border);\n      border-radius: 26px 26px 0 0;\n    }\n\n    .ols-lightbox-link {\n      display: inline-flex;\n      max-width: 100%;\n      justify-content: center;\n      text-decoration: none;\n      cursor: zoom-in;\n      overflow: visible;\n    }\n\n    .ols-zoomable-img {\n      max-width: 100%;\n      height: auto;\n      display: block;\n      object-fit: contain;\n      transform-origin: center center;\n      transition: transform 0.25s ease, filter 0.25s ease, box-shadow 0.25s ease;\n      will-change: transform;\n      position: relative;\n      z-index: 1;\n      border-radius: 12px;\n    }\n\n    .ols-lightbox-link:hover .ols-zoomable-img,\n    .ols-lightbox-link:focus-visible .ols-zoomable-img {\n      transform: scale(1.5);\n      filter: drop-shadow(0 24px 44px rgba(28, 36, 75, 0.24));\n      z-index: 60;\n    }\n\n    .ols-zoom-card-caption {\n      padding: 22px 26px 24px;\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n      border-radius: 0 0 26px 26px;\n    }\n\n    .ols-zoom-card-caption p {\n      margin: 0;\n      color: #5f6b85;\n      font-size: clamp(16px, 1.4vw, 19px);\n      line-height: 1.65;\n      font-weight: 300;\n      font-style: italic;\n    }\n\n    .ols-lightbox-overlay {\n      position: fixed;\n      inset: 0;\n      z-index: 999999;\n      display: none;\n      align-items: center;\n      justify-content: center;\n      padding: 64px 28px 28px;\n      background: rgba(8, 13, 32, 0.88);\n      backdrop-filter: blur(8px);\n    }\n\n    .ols-lightbox-overlay.is-open { display: flex; }\n\n    .ols-lightbox-img {\n      max-width: 96vw;\n      max-height: 88vh;\n      width: auto;\n      height: auto;\n      object-fit: contain;\n      border-radius: 18px;\n      background: #ffffff;\n      box-shadow: 0 28px 80px rgba(0, 0, 0, 0.45);\n    }\n\n    .ols-lightbox-close {\n      position: fixed;\n      top: 18px;\n      right: 22px;\n      width: 46px;\n      height: 46px;\n      border: 0;\n      border-radius: 999px;\n      background: #ffffff;\n      color: var(--navy);\n      font-size: 32px;\n      line-height: 1;\n      cursor: pointer;\n      display: flex;\n      align-items: center;\n      justify-content: center;\n      box-shadow: 0 12px 30px rgba(0, 0, 0, 0.28);\n    }\n\n    @media (max-width: 760px) {\n      .ols-zoom-card { border-radius: 22px; }\n      .ols-zoom-card-image { min-height: 250px; padding: 14px; border-radius: 22px 22px 0 0; }\n      .ols-zoom-card-caption { padding: 18px; border-radius: 0 0 22px 22px; }\n      .ols-lightbox-link:hover .ols-zoomable-img,\n      .ols-lightbox-link:focus-visible .ols-zoomable-img { transform: none; filter: none; }\n    }\n\n  \n    .ols-figure-placeholder .ols-placeholder-box { border: 2px dashed #c9973a; background: #fffaf0; border-radius: 16px; padding: 26px 22px; font-weight: 700; color: #7a4b12; text-align: center; line-height: 1.6; }\n    .ols-figure-placeholder .ols-figure-image { background: transparent; }\n    .ols-figure-placeholder { background: #ffffff; border: 1px solid rgba(28, 36, 75, 0.12); border-radius: 22px; padding: 14px; margin: 18px 0 6px; }\n    .ols-figure-placeholder .ols-figure-caption p { margin: 10px 0 0; font-size: 14px; color: #667085; text-align: center; }\n<\/style>\n\n  <aside class=\"ols-sidebar\">\n  <div class=\"ols-sidebar-header\">\n    <h3>Revision Notes<\/h3>\n    <p>OCR A Level Chemistry A<\/p>\n  <\/div>\n\n  <div class=\"ols-topic-group\">\n    <h4>4.1.3 Alkenes<\/h4>\n\n    <ul class=\"ols-topic-list\">\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/alkene-bonding\/\">Alkene Bonding<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/geometric-isomerism\/\">Geometric Isomerism<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/electrophilic-addition-mechanism\/\">Electrophilic Addition Mechanism<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/reactions-of-alkenes\/\">Reactions of Alkenes<\/a>\n\n        <ul class=\"ols-subtopic-list\">\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/reactions-of-alkenes\/hydrogen\/\">Hydrogen<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/reactions-of-alkenes\/halogens\/\">Halogens<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/reactions-of-alkenes\/bromine-water\/\">Bromine Water<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/reactions-of-alkenes\/hydrogen-halide\/\">Hydrogen Halide<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/reactions-of-alkenes\/steam\/\">Steam<\/a>\n          <\/li>\n        <\/ul>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/polymerisation-reactions\/\">Polymerisation Reactions<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/polymer-waste\/\">Polymer Waste<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/\">Processing Waste Polymers<\/a>\n      <\/li>\n    <\/ul>\n  <\/div>\n\n  <div class=\"ols-topic-group\">\n    <h4>Next Sections<\/h4>\n\n    <ul class=\"ols-topic-list\">\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-1-basic-concepts-of-organic-chemistry\/\">4.1.1 Basic Concepts of Organic Chemistry<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-2-1-alcohols\/\">4.2.1 Alcohols<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-2-2-haloalkanes\/\">4.2.2 Haloalkanes<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-2-alkanes\/\">4.1.2 Alkanes<\/a>\n      <\/li>\n    <\/ul>\n  <\/div>\n<\/aside>\n\n<script>\r\n(function() {\r\n  function normalisePath(path) {\r\n    return String(path || '')\r\n      .split('?')[0]\r\n      .split('#')[0]\r\n      .replace(\/\\\/+$\/, '')\r\n      .toLowerCase();\r\n  }\r\n\r\n  function highlightActive() {\r\n    var sidebar = document.querySelector('.ols-sidebar');\r\n    if (!sidebar) return false;\r\n\r\n    var currentPath = normalisePath(window.location.pathname);\r\n    var links = sidebar.querySelectorAll('a[href]');\r\n    var matched = null;\r\n    var matchedLength = 0;\r\n\r\n    sidebar.querySelectorAll('.active, .active-main, .parent-active').forEach(function(item) {\r\n      item.classList.remove('active', 'active-main', 'parent-active');\r\n    });\r\n\r\n    sidebar.querySelectorAll('a[data-ols-disabled-parent=\"1\"], a[aria-current]').forEach(function(a) {\r\n      a.removeAttribute('aria-current');\r\n      a.removeAttribute('tabindex');\r\n      a.removeAttribute('data-ols-disabled-parent');\r\n    });\r\n\r\n    links.forEach(function(a) {\r\n      try {\r\n        var href = a.getAttribute('href');\r\n\r\n        if (!href || href === '#' || href.charAt(0) === '#') {\r\n          return;\r\n        }\r\n\r\n        var linkPath = normalisePath(new URL(href, window.location.origin).pathname);\r\n\r\n        if (!linkPath) {\r\n          return;\r\n        }\r\n\r\n        if (currentPath === linkPath || currentPath.indexOf(linkPath + '\/') === 0) {\r\n          if (linkPath.length > matchedLength) {\r\n            matched = a;\r\n            matchedLength = linkPath.length;\r\n          }\r\n        }\r\n      } catch(e) {}\r\n    });\r\n\r\n    if (matched) {\r\n      var matchedLi = matched.closest('li');\r\n      var parentSub = matched.closest('.ols-subtopic-list');\r\n\r\n      if (parentSub) {\r\n        if (matchedLi) {\r\n          matchedLi.classList.add('active');\r\n          matched.setAttribute('aria-current', 'page');\r\n        }\r\n\r\n        var parentLi = parentSub.closest('li');\r\n\r\n        if (parentLi) {\r\n          parentLi.classList.add('parent-active', 'active-main');\r\n\r\n          var parentLink = parentLi.querySelector(':scope > a');\r\n\r\n          if (parentLink) {\r\n            parentLink.setAttribute('aria-current', 'true');\r\n            parentLink.setAttribute('tabindex', '-1');\r\n            parentLink.setAttribute('data-ols-disabled-parent', '1');\r\n          }\r\n        }\r\n      } else {\r\n        if (matchedLi) {\r\n          matchedLi.classList.add('parent-active', 'active-main');\r\n          matched.setAttribute('aria-current', 'page');\r\n          matched.setAttribute('tabindex', '-1');\r\n          matched.setAttribute('data-ols-disabled-parent', '1');\r\n        }\r\n      }\r\n    }\r\n\r\n    return true;\r\n  }\r\n\r\n  if (!highlightActive()) {\r\n    document.addEventListener('DOMContentLoaded', highlightActive);\r\n  }\r\n})();\r\n<\/script>\n\n  <main class=\"ols-main\">\n      <nav class=\"ols-breadcrumbs\" aria-label=\"Breadcrumb\">\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\">Revision Notes<\/a> \/\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\">A Level Chemistry<\/a> \/\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/\">OCR A<\/a> \/\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/\">4.1.3 Alkenes<\/a> \/\n<span>Processing Waste Polymers<\/span>\n<\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Processing Waste Polymers<\/h1>\n        <p class=\"ols-page-intro\">A concise OCR A Level Chemistry A revision guide to the two ways waste polymers are processed for sustainability in 4.1.3(k): combustion for energy production, and use as an organic feedstock for making new plastics and other organic chemicals.<\/p>\n        <div class=\"ols-badges\">\n          <div class=\"ols-badge\">Paper 2<\/div>\n<div class=\"ols-badge\">4.1.3: Alkenes<\/div>\n<div class=\"ols-badge\">H432\/02<\/div>\n        <\/div>\n        <div class=\"ols-author\">\n\n    <img decoding=\"async\"\n      class=\"ols-author-avatar-img\"\n      src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\"\n      alt=\"Dr. Mohammed Al-Fatah\"\n    >\n\n    <div class=\"ols-author-content\">\n\n      <h2 class=\"ols-author-title\">\n        Written by: Dr. Mohammed Al-Fatah\n      <\/h2>\n\n      <p class=\"ols-author-description\">\n        Chemistry specialist revision notes for A Level Chemistry.\n      <\/p>\n\n      <a class=\"ols-linkedin-pill\" href=\"https:\/\/www.linkedin.com\/in\/doctormohammedfatah\/\" target=\"_blank\" rel=\"noopener noreferrer\">\n        <svg class=\"ols-linkedin-icon\" viewBox=\"0 0 24 24\" fill=\"currentColor\" aria-hidden=\"true\">\n          <path d=\"M4.98 3.5C4.98 4.88 3.86 6 2.48 6S0 4.88 0 3.5 1.12 1 2.48 1s2.5 1.12 2.5 2.5zM.5 8h4V24h-4V8zm7 0h3.8v2.2h.1c.5-.9 1.8-2.2 3.9-2.2 4.2 0 5 2.8 5 6.4V24h-4v-7.6c0-1.8 0-4.2-2.6-4.2s-3 2-3 4v7.8h-4V8z\"\/>\n        <\/svg>\n        View LinkedIn Profile\n      <\/a>\n\n    <\/div>\n\n  <\/div>\n      <\/header>\n\n      <section class=\"ols-h5p-card ols-h5p-inline ols-h5p-recap\">\n<span class=\"ols-h5p-kicker\">Before you start<\/span>\n<h2>GCSE Recap: Plastics, Burning and Landfill<\/h2>\n<p>Three quick questions on the GCSE ideas about polymers that this page builds on.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-content\" data-content-id=\"801\"><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">1<\/div>\n<h2>Why Waste Polymers Are Processed<\/h2>\n<\/div>\n<p>Poly(alkenes) are made from <strong>crude oil<\/strong>, a finite resource, and because their chains are saturated and non-polar they do not break down in landfill. OCR 4.1.3(k) asks for the <strong>benefits for sustainability<\/strong> of processing waste polymers rather than burying them.<\/p>\n<p>Three routes are named in the specification. This page covers the first two in detail: <strong>combustion for energy production<\/strong> and <strong>use as an organic feedstock<\/strong>. The third, removing toxic waste products such as HCl when halogenated plastics are burned, is covered on the <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/polymer-waste\/\">Polymer Waste<\/a> page.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>OCR 4.1.3(k) route<\/th><th>What happens to the polymer<\/th><th>What is recovered<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>(i) Combustion for energy production<\/strong><\/td><td>Burned in an energy-from-waste plant<\/td><td>Heat, used to generate electricity<\/td><\/tr>\n<tr><td><strong>(ii) Use as an organic feedstock<\/strong><\/td><td>Cracked back into small molecules<\/td><td>Alkenes and other chemicals for new products<\/td><\/tr>\n<tr><td><strong>(iii) Removal of toxic waste products<\/strong><\/td><td>Acidic gases from combustion neutralised<\/td><td>A cleaner waste stream<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Key idea:<\/strong> Sustainability means meeting present needs without using up resources or damaging the environment for the future. Each route either recovers something useful from the waste or reduces the harm it causes.<\/p>\n<\/div>\n<\/article>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">2<\/div>\n<h2>Combustion for Energy Production<\/h2>\n<\/div>\n<p>Poly(alkenes) are <strong>hydrocarbons<\/strong>, so they burn in the same way as the alkanes they were made from. In an <strong>energy-from-waste<\/strong> plant, sorted waste polymers are burned in a controlled incinerator. The heat released turns water into steam, which drives a turbine to <strong>generate electricity<\/strong>.<\/p>\n<p>For the repeat unit of poly(ethene) the combustion is:<\/p>\n<p>-(CH<sub>2<\/sub>-CH<sub>2<\/sub>)- + 3O<sub>2<\/sub> \u2192 2CO<sub>2<\/sub> + 2H<sub>2<\/sub>O<\/p>\n<p>Because the polymer chains contain many C-H bonds, the <strong>energy released per kilogram<\/strong> is similar to that of the fuel oil the polymer was made from. This is why combustion is described as <strong>energy recovery<\/strong>: the energy stored in the crude oil is not wasted even though the plastic itself is destroyed.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Benefit for sustainability<\/th><th>Explanation<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Reduces landfill<\/strong><\/td><td>The volume of waste is cut by more than 90 per cent, so less land is needed for disposal<\/td><\/tr>\n<tr><td><strong>Reduces fossil fuel use<\/strong><\/td><td>Electricity generated from the waste replaces electricity that would have been made by burning coal, oil or gas<\/td><\/tr>\n<tr><td><strong>Works for mixed or dirty plastics<\/strong><\/td><td>Polymers that are too contaminated or too mixed to recycle can still be used<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Combustion does have costs. It still releases <strong>carbon dioxide<\/strong>, and plastics that contain chlorine, such as PVC, form <strong>hydrogen chloride<\/strong> which must be removed from the flue gases with a base such as calcium oxide. That is why OCR lists the removal of toxic waste products as a separate benefit in 4.1.3(k)(iii).<\/p>\n<div class=\"ols-figure-card ols-zoom-pop\">\n<div class=\"ols-figure-image\">\n<a class=\"ols-image-fullscreen-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/wave-21.jpg\" target=\"_blank\" rel=\"noopener\" aria-label=\"Open image fullscreen\">\n<img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/wave-21.jpg\" alt=\"Energy-from-waste plant flow diagram, redrawn flat, with a single clean steam arrow that touches the boiler.\" data-fullscreen-src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/wave-21.jpg\">\n<\/a>\n<\/div>\n<div class=\"ols-figure-caption\"><p>Energy recovery: the heat from burning waste polymers is used to generate electricity.<\/p><\/div>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Exam sentence:<\/strong> Burning waste polymers releases energy which can be used to generate electricity, reducing both landfill and the amount of fossil fuel burned.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: The Acidic Gas in the Flue Gases<\/h2>\n<p>Decide which polymer in a mixed load causes the problem, and what deals with it.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-361\" class=\"h5p-iframe\" data-content-id=\"361\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Waste Polymers MCQ: Which Waste Makes an Acidic Flue Gas?\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card purple\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">3<\/div>\n<h2>Use as an Organic Feedstock<\/h2>\n<\/div>\n<p>A <strong>feedstock<\/strong> is a raw material for a chemical process. Waste poly(alkenes) can be heated in the absence of air so that the long chains <strong>crack<\/strong> into smaller molecules, mainly <strong>alkenes and alkanes<\/strong>. This is the same type of reaction used to crack the heavy fractions of crude oil.<\/p>\n<p>The alkenes produced can be <strong>polymerised again<\/strong> to make new plastics, or used as the starting point for other organic chemicals such as alcohols and solvents. The waste polymer therefore replaces crude oil as the source of these molecules.<\/p>\n<p>For example, cracking waste poly(propene) can give propene, which is then re-polymerised:<\/p>\n<p>-(CH<sub>2<\/sub>-CH(CH<sub>3<\/sub>))<sub>n<\/sub>&#8211; \u2192 n CH<sub>2<\/sub>=CHCH<sub>3<\/sub> \u2192 new poly(propene)<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Benefit for sustainability<\/th><th>Explanation<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Conserves crude oil<\/strong><\/td><td>The carbon in the waste is reused, so less oil has to be extracted and cracked to make new plastics<\/td><\/tr>\n<tr><td><strong>Handles mixed polymers<\/strong><\/td><td>Cracking works on a mixture of poly(alkenes) that would be difficult to sort for ordinary recycling<\/td><\/tr>\n<tr><td><strong>Keeps the chemical value<\/strong><\/td><td>Unlike combustion, the atoms end up in useful products rather than in carbon dioxide<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>The process needs energy for heating and the products must be separated by fractional distillation before they can be used, so it is more expensive than burning the waste. It is also unsuitable for polymers containing chlorine unless the HCl is dealt with first.<\/p>\n<div class=\"ols-figure-card ols-zoom-pop\">\n<div class=\"ols-figure-image\">\n<a class=\"ols-image-fullscreen-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/wave-22.jpg\" target=\"_blank\" rel=\"noopener\" aria-label=\"Open image fullscreen\">\n<img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/wave-22.jpg\" alt=\"Feedstock recycling of poly(propene): the waste chain drawn as a section with dots only, never as three units in brackets with n.\" data-fullscreen-src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/wave-22.jpg\">\n<\/a>\n<\/div>\n<div class=\"ols-figure-caption\"><p>Feedstock recycling: cracking returns the polymer to small molecules that can be polymerised again or converted into other chemicals.<\/p><\/div>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Exam sentence:<\/strong> Waste polymers can be cracked into alkenes and other small molecules, which are then used as a feedstock to make new plastics and organic chemicals, conserving crude oil.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Three Options for One Waste Stream<\/h2>\n<p>Drag the words into the gaps to work through what each option recovers.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-360\" class=\"h5p-iframe\" data-content-id=\"360\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Waste Polymers Drag: Three Options for a Dirty Plastic Film\"><\/iframe><\/div><\/div>\n<\/section>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Put the Stages in Order<\/h2>\n<p>Six stages of a feedstock recycling plant, to be put into the order in which they happen.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-802\" class=\"h5p-iframe\" data-content-id=\"802\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Waste Polymers Sort: Stages of Feedstock Recycling\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">4<\/div>\n<h2>Comparing the Two Routes<\/h2>\n<\/div>\n<p>Examiners often ask you to compare the routes or to choose the more sustainable option for a given waste stream. The table gathers the points that earn marks.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Feature<\/th><th>Combustion for energy<\/th><th>Organic feedstock<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>What is recovered<\/strong><\/td><td>Energy, as electricity<\/td><td>Chemicals, as alkenes and other molecules<\/td><\/tr>\n<tr><td><strong>Effect on crude oil use<\/strong><\/td><td>Replaces oil burned for electricity<\/td><td>Replaces oil cracked for new plastics<\/td><\/tr>\n<tr><td><strong>Carbon dioxide<\/strong><\/td><td>All the carbon becomes CO<sub>2<\/sub><\/td><td>Most carbon stays in useful products<\/td><\/tr>\n<tr><td><strong>Waste needed<\/strong><\/td><td>Mixed and contaminated plastics acceptable<\/td><td>Mixed poly(alkenes) acceptable; chlorinated plastics need pre-treatment<\/td><\/tr>\n<tr><td><strong>Main limitation<\/strong><\/td><td>Toxic gases such as HCl must be removed<\/td><td>Energy and separation costs<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Exam focus:<\/strong> Name the route, state what is recovered, and link it to sustainability: less landfill, less crude oil used, or fewer harmful emissions.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Choose a Route and Justify It<\/h2>\n<p>Write a short explanation, then compare it with the mark points and the model answer.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-363\" class=\"h5p-iframe\" data-content-id=\"363\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Waste Polymers Explain: Choosing the Route That Saves Crude Oil\"><\/iframe><\/div><\/div>\n<\/section>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Judge Four Claims<\/h2>\n<p>In each round, choose the one statement that is accurate.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-362\" class=\"h5p-iframe\" data-content-id=\"362\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Waste Polymers Summary: Judging Four Claims About Plastic Waste\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card purple\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">5<\/div>\n<h2>Common Exam Mistakes<\/h2>\n<\/div>\n<ul>\n<li>Describing combustion as simply &#8220;burning the plastic&#8221;. State that the <strong>energy released is used to generate electricity<\/strong>.<\/li>\n<li>Confusing feedstock recycling with ordinary recycling. Melting and remoulding keeps the polymer; feedstock recycling <strong>cracks it into new molecules<\/strong>.<\/li>\n<li>Forgetting that cracking waste polymers gives <strong>alkenes<\/strong>, which is why the products can be polymerised again.<\/li>\n<li>Ignoring the drawbacks. A balanced answer mentions carbon dioxide from combustion and the energy needed for cracking.<\/li>\n<\/ul>\n<div class=\"ols-key-box\">\n<p><strong>Exam sentence:<\/strong> Processing waste polymers by combustion or as an organic feedstock reduces landfill and conserves crude oil, which is why OCR describes both as benefits for sustainability.<\/p>\n<\/div>\n<\/article>\n\n<section class=\"ols-course-cta-alkenes\" id=\"olsCourseCtaAlkenes001\">\r\n  <style>\r\n    .ols-course-cta-alkenes,\r\n    .ols-course-cta-alkenes * {\r\n      box-sizing: border-box;\r\n    }\r\n\r\n    .ols-course-cta-alkenes {\r\n      --navy: #1C244B;\r\n      --blue: #2563eb;\r\n      --body-text: #1f2937;\r\n      --grey-text: #667085;\r\n      --border: rgba(28, 36, 75, 0.14);\r\n      --shadow: 0 18px 45px rgba(28, 36, 75, 0.12);\r\n      --inner-shadow: 0 10px 26px rgba(28, 36, 75, 0.08);\r\n\r\n      width: 100%;\r\n      margin: 30px 0 24px;\r\n      font-family: Poppins, Arial, sans-serif;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-card {\r\n      overflow: hidden;\r\n      border-radius: 30px;\r\n      border: 1px solid var(--border);\r\n      background:\r\n        radial-gradient(circle at top left, rgba(37, 99, 235, 0.16), transparent 34%),\r\n        linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\r\n      box-shadow: var(--shadow);\r\n      padding: 30px;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-top {\r\n      display: grid;\r\n      grid-template-columns: minmax(260px, 0.9fr) minmax(0, 1.1fr);\r\n      gap: 28px;\r\n      align-items: center;\r\n      margin-bottom: 24px;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-image-link {\r\n      display: block;\r\n      text-decoration: none;\r\n      border-radius: 24px;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-image {\r\n      width: 100%;\r\n      border-radius: 24px;\r\n      overflow: hidden;\r\n      border: 1px solid var(--border);\r\n      background: #ffffff;\r\n      box-shadow: var(--inner-shadow);\r\n      transition:\r\n        transform 0.35s ease,\r\n        box-shadow 0.35s ease;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-image img {\r\n      width: 100%;\r\n      height: auto;\r\n      display: block;\r\n      transition: transform 0.45s ease;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-image-link:hover .ols-course-cta-image {\r\n      transform: translateY(-8px) scale(1.015);\r\n      box-shadow:\r\n        0 26px 60px rgba(28, 36, 75, 0.18),\r\n        0 0 0 1px rgba(37, 99, 235, 0.12);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-image-link:hover .ols-course-cta-image img {\r\n      transform: scale(1.03);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-header-row {\r\n      display: flex;\r\n      flex-wrap: wrap;\r\n      align-items: center;\r\n      justify-content: space-between;\r\n      gap: 14px;\r\n      margin-bottom: 18px;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-kicker {\r\n      display: inline-flex;\r\n      align-items: center;\r\n      padding: 8px 14px;\r\n      border-radius: 999px;\r\n      background: #ffffff;\r\n      border: 1px solid rgba(37, 99, 235, 0.18);\r\n      color: var(--blue);\r\n      font-size: 14px;\r\n      line-height: 1.2;\r\n      font-weight: 700;\r\n      box-shadow: var(--inner-shadow);\r\n    }\r\n\r\n    .ols-course-cta-alkenes h2 {\r\n      margin: 0 0 14px;\r\n      font-size: clamp(28px, 3.5vw, 42px);\r\n      line-height: 1.15;\r\n      font-weight: 800;\r\n      letter-spacing: -0.03em;\r\n      color: #111827;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-intro-stats {\r\n      display: grid;\r\n      grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);\r\n      gap: 24px;\r\n      align-items: stretch;\r\n      margin: 0 0 30px;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-intro {\r\n      margin: 0;\r\n      color: var(--body-text);\r\n      font-size: clamp(16px, 1.4vw, 18px);\r\n      line-height: 1.7;\r\n      font-weight: 300;\r\n      align-self: center;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-stats {\r\n      display: grid;\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n      gap: 14px;\r\n      margin: 0;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-stat {\r\n      background: #ffffff;\r\n      border: 1px solid var(--border);\r\n      border-radius: 18px;\r\n      padding: 16px;\r\n      box-shadow: var(--inner-shadow);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-stat span {\r\n      display: block;\r\n      margin-bottom: 6px;\r\n      color: var(--grey-text);\r\n      font-size: 13px;\r\n      line-height: 1.35;\r\n      font-weight: 700;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-stat strong {\r\n      display: block;\r\n      color: var(--navy);\r\n      font-size: 18px;\r\n      line-height: 1.35;\r\n      font-weight: 800;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-features {\r\n      display: grid;\r\n      grid-template-columns: repeat(2, minmax(0, 1fr));\r\n      gap: 14px;\r\n      margin: 0 0 30px;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-feature {\r\n      background: rgba(255, 255, 255, 0.78);\r\n      border: 1px solid var(--border);\r\n      border-radius: 18px;\r\n      padding: 16px 18px;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-feature h3 {\r\n      margin: 0 0 6px;\r\n      color: var(--navy);\r\n      font-size: 18px;\r\n      line-height: 1.3;\r\n      font-weight: 800;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-feature p {\r\n      margin: 0;\r\n      color: var(--body-text);\r\n      font-size: 15px;\r\n      line-height: 1.6;\r\n      font-weight: 300;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-animation-wrap {\r\n      position: relative;\r\n      margin: 0 0 30px;\r\n      border-radius: 0;\r\n      overflow: visible;\r\n      border: 0;\r\n      background: transparent;\r\n      box-shadow: none;\r\n      padding: 0;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-animation-title {\r\n      margin: 0 0 18px;\r\n      text-align: center;\r\n      color: var(--navy);\r\n      font-size: clamp(26px, 3.2vw, 40px);\r\n      line-height: 1.15;\r\n      font-weight: 700;\r\n      letter-spacing: -0.03em;\r\n      text-shadow: -9px 0 9px rgba(28, 36, 75, 0.10);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-frame-shell {\r\n      position: relative;\r\n      width: 100%;\r\n      height: 620px;\r\n      border-radius: 24px;\r\n      overflow: hidden;\r\n      background:\r\n        radial-gradient(circle at top left, rgba(70, 127, 247, 0.14), transparent 34%),\r\n        linear-gradient(135deg, #f8fbff 0%, #e9efff 100%);\r\n      box-shadow: 0 24px 64px rgba(28, 36, 75, 0.18);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-frame-shell iframe {\r\n      display: block;\r\n      width: 100%;\r\n      height: 100%;\r\n      border: 0;\r\n      background: #e9efff;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-start-overlay {\r\n      position: absolute;\r\n      inset: 0;\r\n      z-index: 5;\r\n      display: flex;\r\n      align-items: center;\r\n      justify-content: center;\r\n      border: 0;\r\n      cursor: pointer;\r\n      background:\r\n        radial-gradient(circle at center, rgba(255, 255, 255, 0.26), rgba(28, 36, 75, 0.28)),\r\n        url(\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/ocr-a-level-chemistry-a-4-1-3-alkenes-interactive-course-banner-v2.jpg\");\r\n      background-size: cover;\r\n      background-position: center;\r\n      transition:\r\n        opacity 0.35s ease,\r\n        visibility 0.35s ease;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-start-overlay::before {\r\n      content: \"\";\r\n      position: absolute;\r\n      inset: 0;\r\n      background: rgba(28, 36, 75, 0.30);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-start-overlay.is-hidden {\r\n      opacity: 0;\r\n      visibility: hidden;\r\n      pointer-events: none;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-start-content {\r\n      position: relative;\r\n      z-index: 2;\r\n      display: grid;\r\n      justify-items: center;\r\n      gap: 16px;\r\n      padding: 24px;\r\n      text-align: center;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-play-circle {\r\n      width: 96px;\r\n      height: 96px;\r\n      border-radius: 50%;\r\n      background: #ffffff;\r\n      color: var(--navy);\r\n      display: flex;\r\n      align-items: center;\r\n      justify-content: center;\r\n      box-shadow:\r\n        0 18px 40px rgba(28, 36, 75, 0.30),\r\n        0 0 0 12px rgba(255, 255, 255, 0.22);\r\n      animation: olsAnimationPlayPulse001 1.8s ease-in-out infinite;\r\n      transition:\r\n        transform 0.25s ease,\r\n        background 0.25s ease,\r\n        color 0.25s ease;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-start-overlay:hover .ols-animation-play-circle {\r\n      transform: scale(1.08);\r\n      background: var(--navy);\r\n      color: #ffffff;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-play-icon {\r\n      width: 0;\r\n      height: 0;\r\n      margin-left: 7px;\r\n      border-top: 18px solid transparent;\r\n      border-bottom: 18px solid transparent;\r\n      border-left: 28px solid currentColor;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-start-text {\r\n      max-width: 540px;\r\n      margin: 0;\r\n      color: #ffffff;\r\n      font-size: clamp(20px, 3vw, 32px);\r\n      line-height: 1.2;\r\n      font-weight: 800;\r\n      text-shadow: 0 8px 20px rgba(0, 0, 0, 0.28);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-pause-button {\r\n      position: absolute;\r\n      left: 16px;\r\n      bottom: 16px;\r\n      z-index: 7;\r\n      display: none;\r\n      align-items: center;\r\n      justify-content: center;\r\n      min-width: 92px;\r\n      padding: 10px 16px;\r\n      border: 0;\r\n      border-radius: 999px;\r\n      background: rgba(28, 36, 75, 0.92);\r\n      color: #ffffff;\r\n      font-family: Poppins, Arial, sans-serif;\r\n      font-size: 14px;\r\n      line-height: 1.2;\r\n      font-weight: 800;\r\n      cursor: pointer;\r\n      box-shadow: 0 12px 28px rgba(28, 36, 75, 0.24);\r\n      transition:\r\n        transform 0.2s ease,\r\n        background 0.2s ease,\r\n        box-shadow 0.2s ease;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-pause-button:hover {\r\n      transform: translateY(-2px);\r\n      background: var(--blue);\r\n      box-shadow: 0 16px 34px rgba(37, 99, 235, 0.28);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-animation-pause-button.is-visible {\r\n      display: inline-flex;\r\n    }\r\n\r\n    @keyframes olsAnimationPlayPulse001 {\r\n      0% {\r\n        box-shadow:\r\n          0 18px 40px rgba(28, 36, 75, 0.30),\r\n          0 0 0 0 rgba(255, 255, 255, 0.40);\r\n      }\r\n\r\n      70% {\r\n        box-shadow:\r\n          0 18px 40px rgba(28, 36, 75, 0.30),\r\n          0 0 0 18px rgba(255, 255, 255, 0);\r\n      }\r\n\r\n      100% {\r\n        box-shadow:\r\n          0 18px 40px rgba(28, 36, 75, 0.30),\r\n          0 0 0 0 rgba(255, 255, 255, 0);\r\n      }\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-video-status {\r\n      margin: 14px 0 0;\r\n      text-align: center;\r\n      color: var(--grey-text);\r\n      font-size: 13px;\r\n      line-height: 1.5;\r\n      font-weight: 500;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-cta-bottom {\r\n      display: flex;\r\n      justify-content: center;\r\n      padding-top: 22px;\r\n      border-top: 1px solid var(--border);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-button {\r\n      display: inline-flex;\r\n      align-items: center;\r\n      justify-content: center;\r\n      padding: 15px 28px;\r\n      border-radius: 999px;\r\n      background: var(--navy);\r\n      color: #ffffff;\r\n      text-decoration: none;\r\n      font-size: 16px;\r\n      line-height: 1.2;\r\n      font-weight: 800;\r\n      box-shadow: 0 12px 26px rgba(28, 36, 75, 0.18);\r\n      transition:\r\n        transform 0.2s ease,\r\n        background 0.2s ease,\r\n        box-shadow 0.2s ease;\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-button:hover {\r\n      transform: translateY(-2px);\r\n      background: var(--blue);\r\n      color: #ffffff;\r\n      box-shadow: 0 16px 32px rgba(37, 99, 235, 0.24);\r\n    }\r\n\r\n    .ols-course-cta-alkenes .ols-course-button-top {\r\n      flex-shrink: 0;\r\n      padding: 12px 22px;\r\n      font-size: 15px;\r\n    }\r\n\r\n    @media (max-width: 900px) {\r\n      .ols-course-cta-alkenes .ols-course-cta-top {\r\n        grid-template-columns: 1fr;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-cta-image-link {\r\n        max-width: 520px;\r\n        margin: 0 auto;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-cta-intro-stats {\r\n        grid-template-columns: 1fr;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-animation-frame-shell {\r\n        height: 520px;\r\n      }\r\n    }\r\n\r\n    @media (max-width: 760px) {\r\n      .ols-course-cta-alkenes {\r\n        margin: 26px 0 22px;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-cta-card {\r\n        padding: 20px;\r\n        border-radius: 24px;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-cta-header-row {\r\n        align-items: stretch;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-button-top {\r\n        width: 100%;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-cta-stats,\r\n      .ols-course-cta-alkenes .ols-course-cta-features {\r\n        grid-template-columns: 1fr;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-animation-wrap {\r\n        padding: 0;\r\n        border-radius: 0;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-animation-frame-shell {\r\n        height: 420px;\r\n        border-radius: 18px;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-animation-play-circle {\r\n        width: 76px;\r\n        height: 76px;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-animation-play-icon {\r\n        border-top-width: 14px;\r\n        border-bottom-width: 14px;\r\n        border-left-width: 22px;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-animation-pause-button {\r\n        left: 12px;\r\n        bottom: 12px;\r\n        min-width: 84px;\r\n        padding: 9px 14px;\r\n        font-size: 13px;\r\n      }\r\n\r\n      .ols-course-cta-alkenes .ols-course-button {\r\n        width: 100%;\r\n      }\r\n    }\r\n  <\/style>\r\n\r\n  <div class=\"ols-course-cta-card\">\r\n\r\n    <div class=\"ols-course-cta-top\">\r\n\r\n      <a class=\"ols-course-cta-image-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/alkenes-4-1-3-ocr-a\/\" aria-label=\"Open the OCR A Level Chemistry A 4.1.3 Alkenes course page\">\r\n\r\n        <div class=\"ols-course-cta-image\">\r\n          <img decoding=\"async\"\r\n            src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/ocr-a-level-chemistry-a-4-1-3-alkenes-interactive-course-banner-v2.jpg\"\r\n            alt=\"OCR A Level Chemistry A 4.1.3 Alkenes interactive course banner\"\r\n          >\r\n        <\/div>\r\n\r\n      <\/a>\r\n\r\n      <div class=\"ols-course-cta-content\">\r\n\r\n        <div class=\"ols-course-cta-header-row\">\r\n\r\n          <div class=\"ols-course-cta-kicker\">\r\n            OCR H432 | 4.1.3 Alkenes Course\r\n          <\/div>\r\n\r\n          <a class=\"ols-course-button ols-course-button-top\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/alkenes-4-1-3-ocr-a\/\">\r\n            View Course\r\n          <\/a>\r\n\r\n        <\/div>\r\n\r\n        <h2>\r\n          Master Alkenes for OCR A Level Chemistry A\r\n        <\/h2>\r\n\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-cta-intro-stats\">\r\n\r\n      <p class=\"ols-course-cta-intro\">\r\n        Continue from these free revision notes into the full 4.1.3 Alkenes course. The guided video lessons are ready now; the OCR A MCQ bank, teacher-marked short-answer questions and KASP spec-point report are being written, and the course opens for enrolment as soon as they are complete.\r\n      <\/p>\r\n\r\n      <div class=\"ols-course-cta-stats\">\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>Recorded lessons<\/span>\n          <strong>Coming soon<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>Video lessons<\/span>\n          <strong>Coming soon<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>MCQ practice<\/span>\n          <strong>Coming soon<\/strong>\r\n        <\/div>\r\n\r\n        <div class=\"ols-course-stat\">\r\n          <span>SAQ practice<\/span>\n          <strong>Coming soon<\/strong>\r\n        <\/div>\r\n\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-cta-features\">\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Guided video teaching<\/h3>\r\n        <p>\r\n          Learn the chemistry and exam technique through structured video lessons with worked examples and walkthroughs.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Instant MCQ feedback<\/h3>\r\n        <p>\r\n          Auto-marked MCQ quizzes provide immediate diagnostic feedback for every answer choice.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Teacher-marked SAQs<\/h3>\r\n        <p>\r\n          Submit written exam responses and receive chemistry specialist feedback with improvement guidance.\r\n        <\/p>\r\n      <\/div>\r\n\r\n      <div class=\"ols-course-feature\">\r\n        <h3>Progress tracking<\/h3>\r\n        <p>\r\n          Identify strengths and weaknesses across the full 4.1.3 specification with targeted reporting.\r\n        <\/p>\r\n      <\/div>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-animation-wrap\">\r\n\r\n      <h3 class=\"ols-course-animation-title\">\r\n        See how the course works\r\n      <\/h3>\r\n\r\n      <div class=\"ols-animation-frame-shell\">\r\n        <iframe\r\n          id=\"olsCourseAnimationFrame001\"\r\n          title=\"OLS course preview animation\"\r\n          loading=\"lazy\"\r\n          referrerpolicy=\"no-referrer\">\r\n        <\/iframe>\r\n\r\n        <button\r\n          class=\"ols-animation-start-overlay\"\r\n          id=\"olsCourseAnimationStart001\"\r\n          type=\"button\"\r\n          aria-label=\"Play OLS course preview animation\">\r\n          <span class=\"ols-animation-start-content\">\r\n            <span class=\"ols-animation-play-circle\" aria-hidden=\"true\">\r\n              <span class=\"ols-animation-play-icon\"><\/span>\r\n            <\/span>\r\n            <span class=\"ols-animation-start-text\">\r\n              Play course preview animation\r\n            <\/span>\r\n          <\/span>\r\n        <\/button>\r\n\r\n        <button\r\n          class=\"ols-animation-pause-button\"\r\n          id=\"olsCourseAnimationPause001\"\r\n          type=\"button\"\r\n          aria-label=\"Pause course preview animation\">\r\n          Pause\r\n        <\/button>\r\n      <\/div>\r\n\r\n      <p class=\"ols-course-video-status\">\r\n        Click play to start the course preview animation.\r\n      <\/p>\r\n\r\n    <\/div>\r\n\r\n    <div class=\"ols-course-cta-bottom\">\r\n\r\n      <a class=\"ols-course-button\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/product\/alkenes-4-1-3-ocr-a\/\">\r\n        View Alkenes 4.1.3 Course\r\n      <\/a>\r\n\r\n    <\/div>\r\n\r\n  <\/div>\r\n\r\n  <template id=\"olsCourseAnimationTemplate001\">\r\n<!DOCTYPE html>\r\n<html lang=\"en\">\r\n<head>\r\n<meta charset=\"UTF-8\">\r\n<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\r\n<title>OLS Combined Promo Animation<\/title>\r\n\r\n<style>\r\n*{box-sizing:border-box;}\r\n\r\nhtml.ols-animation-paused *,\r\nhtml.ols-animation-paused *::before,\r\nhtml.ols-animation-paused *::after{\r\n  animation-play-state:paused!important;\r\n}\r\n\r\n:root{\r\n  --ols-video-screen-w:1180;\r\n  --ols-video-screen-h:664;\r\n  --ols-video-screen-scale:1;\r\n  --ols-mcq-screen-w:1360;\r\n  --ols-mcq-screen-h:1130;\r\n  --ols-mcq-screen-scale:1;\r\n  --ols-saq-screen-w:1360;\r\n  --ols-saq-screen-h:965;\r\n  --ols-saq-screen-scale:1;\r\n}\r\n\r\nhtml,\r\nbody{\r\n  width:100%;\r\n  height:100%;\r\n}\r\n\r\nbody{\r\n  margin:0;\r\n  overflow:hidden;\r\n  font-family:Poppins,Arial,sans-serif;\r\n  background:#e9efff;\r\n}\r\n\r\n.ols-combined-stage{\r\n  position:relative;\r\n  width:100vw;\r\n  height:100vh;\r\n  overflow:hidden;\r\n  background:\r\n    radial-gradient(circle at top left,rgba(70,127,247,0.14),transparent 34%),\r\n    linear-gradient(135deg,#f8fbff 0%,#e9efff 100%);\r\n}\r\n\r\n.ols-scene{\r\n  position:absolute;\r\n  inset:0;\r\n  width:100vw;\r\n  height:100vh;\r\n  opacity:0;\r\n  visibility:hidden;\r\n  pointer-events:none;\r\n}\r\n\r\n.ols-scene.active{\r\n  opacity:1;\r\n  visibility:visible;\r\n  pointer-events:auto;\r\n}\r\n\r\n.ols-scene.fade-out{\r\n  animation:olsSceneFadeOut 0.85s ease forwards;\r\n}\r\n\r\n@keyframes olsSceneFadeOut{\r\n  to{\r\n    opacity:0;\r\n    visibility:hidden;\r\n  }\r\n}\r\n\r\n.ols-title-cursor{\r\n  display:inline-block;\r\n  width:5px;\r\n  height:0.85em;\r\n  background:#1C244B;\r\n  margin-left:8px;\r\n  transform:translateY(8px);\r\n  animation:olsBlink 0.8s infinite;\r\n}\r\n\r\n.cursor{\r\n  display:inline-block;\r\n  width:3px;\r\n  height:28px;\r\n  background:#1c244b;\r\n  margin-left:3px;\r\n  transform:translateY(5px);\r\n  animation:olsBlink 0.8s infinite;\r\n}\r\n\r\n@keyframes olsBlink{\r\n  0%,45%{opacity:1;}\r\n  46%,100%{opacity:0;}\r\n}\r\n\r\n.ols-video-stage,\r\n.ols-mcq-stage,\r\n.ols-saq-stage{\r\n  width:100vw;\r\n  height:100vh;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  padding:0;\r\n  overflow:hidden;\r\n  background:\r\n    radial-gradient(circle at top left,rgba(70,127,247,0.14),transparent 34%),\r\n    linear-gradient(135deg,#f8fbff 0%,#e9efff 100%);\r\n}\r\n\r\n.ols-video-title-screen,\r\n.ols-mcq-intro-screen,\r\n.ols-saq-intro{\r\n  position:absolute;\r\n  inset:0;\r\n  z-index:50;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  background:\r\n    radial-gradient(circle at top left,rgba(70,127,247,0.14),transparent 34%),\r\n    linear-gradient(135deg,#f8fbff 0%,#e9efff 100%);\r\n  opacity:1;\r\n  visibility:visible;\r\n  pointer-events:none;\r\n}\r\n\r\n.ols-video-title-screen.hide{animation:olsVideoTitleFadeOut 0.85s ease forwards;}\r\n.ols-mcq-intro-screen.hide{animation:olsMcqIntroFadeOut 0.85s ease forwards;}\r\n.ols-saq-intro.hide{animation:olsSaqIntroFadeOut 0.85s ease forwards;}\r\n\r\n@keyframes olsVideoTitleFadeOut{to{opacity:0;visibility:hidden;}}\r\n@keyframes olsMcqIntroFadeOut{to{opacity:0;visibility:hidden;}}\r\n@keyframes olsSaqIntroFadeOut{to{opacity:0;visibility:hidden;}}\r\n\r\n.ols-video-title-wrap,\r\n.ols-mcq-intro-title-wrap,\r\n.ols-saq-intro-title-wrap{\r\n  max-width:1250px;\r\n  padding:0 34px;\r\n  text-align:center;\r\n}\r\n\r\n.ols-video-title,\r\n.ols-mcq-intro-title,\r\n.ols-saq-intro-title{\r\n  margin:0;\r\n  font-family:Poppins,Arial,sans-serif;\r\n  font-size:clamp(52px,8vw,124px);\r\n  font-weight:600;\r\n  line-height:1.08;\r\n  color:#1C244B;\r\n  text-shadow:-9px 0 9px rgba(28,36,75,0.16);\r\n  letter-spacing:-0.045em;\r\n}\r\n\r\n#videoTitleText,\r\n#mcqIntroTitleText,\r\n#saqIntroTitleText{\r\n  white-space:pre-wrap;\r\n}\r\n\r\n.ols-video-scene{\r\n  width:100%;\r\n  height:100%;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  opacity:0;\r\n  visibility:hidden;\r\n}\r\n\r\n.ols-video-scene.show{\r\n  visibility:visible;\r\n  animation:olsVideoSceneIn 1s ease forwards;\r\n}\r\n\r\n@keyframes olsVideoSceneIn{to{opacity:1;}}\r\n\r\n.ols-video-scale-wrap{\r\n  width:calc(var(--ols-video-screen-w) * 1px);\r\n  height:calc(var(--ols-video-screen-h) * 1px);\r\n  transform:scale(var(--ols-video-screen-scale));\r\n  transform-origin:center center;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n}\r\n\r\n.ols-video-card{\r\n  width:1180px;\r\n  height:664px;\r\n  border-radius:28px;\r\n  overflow:hidden;\r\n  background:#1C244B;\r\n  box-shadow:0 28px 80px rgba(28,36,75,0.28);\r\n  transform:translateY(24px) scale(0.96);\r\n  opacity:0;\r\n}\r\n\r\n.ols-video-scene.show .ols-video-card{\r\n  animation:olsVideoCardIn 1s cubic-bezier(.18,.89,.32,1.12) forwards;\r\n  animation-delay:0.2s;\r\n}\r\n\r\n@keyframes olsVideoCardIn{\r\n  to{\r\n    transform:translateY(0) scale(1);\r\n    opacity:1;\r\n  }\r\n}\r\n\r\n.ols-video-card video{\r\n  display:block;\r\n  width:100%;\r\n  height:100%;\r\n  aspect-ratio:16 \/ 9;\r\n  object-fit:cover;\r\n  border:0;\r\n}\r\n\r\n.ols-mcq-scale-wrap,\r\n.ols-saq-scale-wrap{\r\n  width:calc(var(--ols-mcq-screen-w) * 1px);\r\n  height:calc(var(--ols-mcq-screen-h) * 1px);\r\n  transform:scale(var(--ols-mcq-screen-scale));\r\n  transform-origin:center center;\r\n  display:flex;\r\n  justify-content:center;\r\n  align-items:flex-start;\r\n}\r\n\r\n.ols-saq-scale-wrap{\r\n  width:calc(var(--ols-saq-screen-w) * 1px);\r\n  height:calc(var(--ols-saq-screen-h) * 1px);\r\n  transform:scale(var(--ols-saq-screen-scale));\r\n}\r\n\r\n.ols-mcq-screen{\r\n  width:1360px;\r\n  height:1130px;\r\n  border-radius:22px;\r\n  overflow:hidden;\r\n  background:#eaf0ff;\r\n  box-shadow:0 26px 70px rgba(28,36,75,0.22);\r\n  opacity:0;\r\n  transform:translateY(24px) scale(0.96);\r\n}\r\n\r\n.ols-mcq-screen.show{\r\n  animation:olsMcqScreenEnter 1s ease forwards;\r\n}\r\n\r\n@keyframes olsMcqScreenEnter{\r\n  from{opacity:0;transform:translateY(24px) scale(0.96);}\r\n  to{opacity:1;transform:translateY(0) scale(1);}\r\n}\r\n\r\n.mcq-question-area{\r\n  background:#eaf0ff;\r\n  padding:28px 30px 30px;\r\n  position:relative;\r\n  height:610px;\r\n}\r\n\r\n.mcq-question-lead{\r\n  margin:0 0 14px;\r\n  font-size:24px;\r\n  line-height:1.35;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-ionic-table{\r\n  border-collapse:collapse;\r\n  width:500px;\r\n  margin-bottom:8px;\r\n  font-size:21px;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-ionic-table th,\r\n.mcq-ionic-table td{\r\n  border:1.5px solid #c9ced8;\r\n  padding:12px 18px;\r\n  text-align:center;\r\n}\r\n\r\n.mcq-ionic-table th{\r\n  background:#f2f2f2;\r\n  font-weight:700;\r\n}\r\n\r\n.mcq-ionic-table td{\r\n  background:#eaf0ff;\r\n}\r\n\r\n.mcq-question-main{\r\n  margin:6px 0 28px;\r\n  font-size:24px;\r\n  line-height:1.35;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-options-wrap{\r\n  display:flex;\r\n  flex-direction:column;\r\n  gap:17px;\r\n  max-width:1200px;\r\n}\r\n\r\n.mcq-option-row{\r\n  display:flex;\r\n  align-items:center;\r\n  min-height:34px;\r\n  position:relative;\r\n}\r\n\r\n.mcq-radio{\r\n  width:28px;\r\n  height:28px;\r\n  border-radius:50%;\r\n  border:2px solid #6b7280;\r\n  margin-right:16px;\r\n  background:transparent;\r\n  position:relative;\r\n  flex:0 0 auto;\r\n}\r\n\r\n.mcq-radio::after{\r\n  content:\"\";\r\n  position:absolute;\r\n  inset:5px;\r\n  border-radius:50%;\r\n  background:#6b7280;\r\n  opacity:0;\r\n  transform:scale(0.4);\r\n  transition:opacity 0.25s ease,transform 0.25s ease;\r\n}\r\n\r\n.mcq-option-row.selected .mcq-radio::after{\r\n  opacity:1;\r\n  transform:scale(1);\r\n}\r\n\r\n.mcq-radio-ripple{\r\n  position:absolute;\r\n  left:14px;\r\n  top:50%;\r\n  width:28px;\r\n  height:28px;\r\n  border-radius:50%;\r\n  border:2px solid rgba(28,36,75,0.28);\r\n  transform:translate(-50%,-50%) scale(1);\r\n  opacity:0;\r\n  pointer-events:none;\r\n}\r\n\r\n.mcq-option-row.clicking .mcq-radio-ripple{\r\n  animation:mcqRipple 0.75s ease forwards;\r\n}\r\n\r\n@keyframes mcqRipple{\r\n  0%{opacity:0.65;transform:translate(-50%,-50%) scale(1);}\r\n  100%{opacity:0;transform:translate(-50%,-50%) scale(2.5);}\r\n}\r\n\r\n.mcq-option-label{\r\n  font-size:23px;\r\n  color:#111827;\r\n}\r\n\r\n.mcq-specific-feedback{\r\n  display:inline-flex;\r\n  align-items:center;\r\n  margin-left:18px;\r\n  min-height:38px;\r\n  opacity:0;\r\n  transform:translateX(-8px);\r\n}\r\n\r\n.mcq-specific-feedback.show{\r\n  opacity:1;\r\n  transform:translateX(0);\r\n  transition:opacity 0.35s ease,transform 0.35s ease;\r\n}\r\n\r\n.mcq-cross-icon{\r\n  width:26px;\r\n  height:26px;\r\n  border-radius:50%;\r\n  border:2px solid #d83255;\r\n  color:#d83255;\r\n  display:inline-flex;\r\n  justify-content:center;\r\n  align-items:center;\r\n  font-size:18px;\r\n  font-weight:700;\r\n  margin-right:12px;\r\n  opacity:0;\r\n  transform:scale(0.4);\r\n}\r\n\r\n.mcq-cross-icon.show{\r\n  animation:mcqCrossPop 0.35s ease forwards;\r\n}\r\n\r\n@keyframes mcqCrossPop{\r\n  70%{opacity:1;transform:scale(1.18);}\r\n  100%{opacity:1;transform:scale(1);}\r\n}\r\n\r\n.mcq-specific-feedback-text{\r\n  display:inline-block;\r\n  background:#fff4b8;\r\n  color:#111827;\r\n  padding:8px 16px;\r\n  font-size:22px;\r\n  line-height:1.35;\r\n  min-width:850px;\r\n  min-height:44px;\r\n}\r\n\r\n.mcq-submit-button{\r\n  position:absolute;\r\n  right:34px;\r\n  bottom:30px;\r\n  border:0;\r\n  border-radius:999px;\r\n  background:#1C244B;\r\n  color:#ffffff;\r\n  padding:14px 28px;\r\n  font-size:18px;\r\n  font-weight:600;\r\n  box-shadow:0 14px 32px rgba(28,36,75,0.25);\r\n  cursor:default;\r\n  transition:transform 0.2s ease,box-shadow 0.2s ease,background 0.2s ease;\r\n}\r\n\r\n.mcq-submit-button.clicked{\r\n  transform:translateY(2px) scale(0.97);\r\n  background:#26315f;\r\n  box-shadow:0 7px 18px rgba(28,36,75,0.22);\r\n}\r\n\r\n.mcq-general-feedback{\r\n  height:520px;\r\n  background:#fff3c9;\r\n  color:#8a6a00;\r\n  padding:26px 30px 28px;\r\n  font-size:23px;\r\n  line-height:1.34;\r\n  opacity:0;\r\n  transform:translateY(20px);\r\n  transition:opacity 0.7s ease,transform 0.7s ease;\r\n  overflow:hidden;\r\n}\r\n\r\n.mcq-general-feedback.show{\r\n  opacity:1;\r\n  transform:translateY(0);\r\n}\r\n\r\n#mcqGeneralText{\r\n  white-space:pre-wrap;\r\n}\r\n\r\n.mcq-specific-cursor{background:#111827;}\r\n.mcq-general-cursor{background:#8a6a00;}\r\n\r\n.ols-saq-screen{\r\n  width:1360px;\r\n  height:965px;\r\n  border-radius:22px;\r\n  overflow:hidden;\r\n  background:#eaf0ff;\r\n  box-shadow:0 26px 70px rgba(28,36,75,0.22);\r\n  opacity:0;\r\n  transform:translateY(24px) scale(0.96);\r\n}\r\n\r\n.ols-saq-screen.show{\r\n  animation:olsSaqScreenEnter 1s ease forwards;\r\n}\r\n\r\n@keyframes olsSaqScreenEnter{\r\n  from{opacity:0;transform:translateY(24px) scale(0.96);}\r\n  to{opacity:1;transform:translateY(0) scale(1);}\r\n}\r\n\r\n.saq-question-area{\r\n  height:335px;\r\n  background:#eaf0ff;\r\n  padding:30px 40px 32px;\r\n}\r\n\r\n.saq-question-text{\r\n  font-size:25px;\r\n  line-height:1.42;\r\n  color:#111827;\r\n  margin-bottom:22px;\r\n}\r\n\r\n.saq-student-box{\r\n  height:195px;\r\n  background:#f3f4f6;\r\n  border:2px solid #cfd6e3;\r\n  border-radius:8px;\r\n  padding:23px 26px;\r\n  font-size:24px;\r\n  line-height:1.55;\r\n  color:#4b5563;\r\n  position:relative;\r\n  overflow:hidden;\r\n}\r\n\r\n.saq-teacher-feedback{\r\n  height:630px;\r\n  background:#dff3e6;\r\n  color:#075f3b;\r\n  padding:28px 40px 30px;\r\n  font-size:23px;\r\n  line-height:1.47;\r\n  opacity:0;\r\n  transform:translateY(20px);\r\n  transition:opacity 0.7s ease,transform 0.7s ease;\r\n  overflow:hidden;\r\n}\r\n\r\n.saq-teacher-feedback.show{\r\n  opacity:1;\r\n  transform:translateY(0);\r\n}\r\n\r\n#saqTeacherText{\r\n  white-space:pre-wrap;\r\n}\r\n\r\n.saq-teacher-cursor{\r\n  background:#075f3b;\r\n}\r\n\r\n@media(max-width:900px){\r\n  .ols-video-title,\r\n  .ols-mcq-intro-title,\r\n  .ols-saq-intro-title{\r\n    font-size:clamp(42px,11vw,78px);\r\n    line-height:1.12;\r\n  }\r\n\r\n  .ols-title-cursor{\r\n    width:4px;\r\n    margin-left:6px;\r\n  }\r\n\r\n  .ols-video-card{\r\n    border-radius:20px;\r\n  }\r\n}\r\n<\/style>\r\n<\/head>\r\n\r\n<body>\r\n<div class=\"ols-combined-stage\">\r\n\r\n  <section id=\"sceneVideo\" class=\"ols-scene active\">\r\n    <div class=\"ols-video-stage\">\r\n      <div id=\"videoTitleScreen\" class=\"ols-video-title-screen\">\r\n        <div class=\"ols-video-title-wrap\">\r\n          <h1 class=\"ols-video-title\">\r\n            <span id=\"videoTitleText\"><\/span><span id=\"videoTitleCursor\" class=\"ols-title-cursor\"><\/span>\r\n          <\/h1>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <section id=\"videoScene\" class=\"ols-video-scene\">\r\n        <div class=\"ols-video-scale-wrap\">\r\n          <div class=\"ols-video-card\">\r\n            <video\r\n              id=\"lessonVideo\"\r\n              src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Virtual-Lesson.mp4\"\r\n              muted\r\n              playsinline\r\n              preload=\"auto\">\r\n            <\/video>\r\n          <\/div>\r\n        <\/div>\r\n      <\/section>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"sceneMcq\" class=\"ols-scene\">\r\n    <div class=\"ols-mcq-stage\">\r\n      <div id=\"mcqIntroScreen\" class=\"ols-mcq-intro-screen\">\r\n        <div class=\"ols-mcq-intro-title-wrap\">\r\n          <h1 class=\"ols-mcq-intro-title\">\r\n            <span id=\"mcqIntroTitleText\"><\/span><span id=\"mcqIntroTitleCursor\" class=\"ols-title-cursor\"><\/span>\r\n          <\/h1>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ols-mcq-scale-wrap\">\r\n        <main id=\"mcqScreen\" class=\"ols-mcq-screen\">\r\n          <section class=\"mcq-question-area\">\r\n            <p class=\"mcq-question-lead\">Some ionic radii are shown.<\/p>\r\n\r\n            <table class=\"mcq-ionic-table\">\r\n              <thead>\r\n                <tr>\r\n                  <th>Ion<\/th>\r\n                  <th>Ionic radius \/ nm<\/th>\r\n                <\/tr>\r\n              <\/thead>\r\n              <tbody>\r\n                <tr><td>Na<sup>+<\/sup><\/td><td>0.102<\/td><\/tr>\r\n                <tr><td>K<sup>+<\/sup><\/td><td>0.138<\/td><\/tr>\r\n                <tr><td>F<sup>\u2212<\/sup><\/td><td>0.133<\/td><\/tr>\r\n                <tr><td>Cl<sup>\u2212<\/sup><\/td><td>0.180<\/td><\/tr>\r\n              <\/tbody>\r\n            <\/table>\r\n\r\n            <p class=\"mcq-question-main\">Which compound has the strongest ionic bonding?<\/p>\r\n\r\n            <div class=\"mcq-options-wrap\">\r\n              <div id=\"mcqWrongOption\" class=\"mcq-option-row\">\r\n                <span class=\"mcq-radio\"><\/span>\r\n                <span class=\"mcq-radio-ripple\"><\/span>\r\n                <span class=\"mcq-option-label\">sodium chloride<\/span>\r\n\r\n                <span id=\"mcqSpecificFeedback\" class=\"mcq-specific-feedback\">\r\n                  <span id=\"mcqCrossIcon\" class=\"mcq-cross-icon\">\u00d7<\/span>\r\n                  <span class=\"mcq-specific-feedback-text\">\r\n                    <span id=\"mcqSpecificText\"><\/span><span id=\"mcqSpecificCursor\" class=\"cursor mcq-specific-cursor\" style=\"display:none;\"><\/span>\r\n                  <\/span>\r\n                <\/span>\r\n              <\/div>\r\n\r\n              <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">potassium chloride<\/span><\/div>\r\n              <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">sodium fluoride<\/span><\/div>\r\n              <div class=\"mcq-option-row\"><span class=\"mcq-radio\"><\/span><span class=\"mcq-radio-ripple\"><\/span><span class=\"mcq-option-label\">potassium fluoride<\/span><\/div>\r\n            <\/div>\r\n\r\n            <button id=\"mcqSubmitButton\" class=\"mcq-submit-button\">Submit answer<\/button>\r\n          <\/section>\r\n\r\n          <section id=\"mcqGeneralFeedback\" class=\"mcq-general-feedback\">\r\n            <span id=\"mcqGeneralText\"><\/span><span id=\"mcqGeneralCursor\" class=\"cursor mcq-general-cursor\" style=\"display:none;\"><\/span>\r\n          <\/section>\r\n        <\/main>\r\n      <\/div>\r\n    <\/div>\r\n  <\/section>\r\n\r\n  <section id=\"sceneSaq\" class=\"ols-scene\">\r\n    <div class=\"ols-saq-stage\">\r\n      <div id=\"saqIntro\" class=\"ols-saq-intro\">\r\n        <div class=\"ols-saq-intro-title-wrap\">\r\n          <h1 class=\"ols-saq-intro-title\">\r\n            <span id=\"saqIntroTitleText\"><\/span><span id=\"saqIntroTitleCursor\" class=\"ols-title-cursor\"><\/span>\r\n          <\/h1>\r\n        <\/div>\r\n      <\/div>\r\n\r\n      <div class=\"ols-saq-scale-wrap\">\r\n        <main id=\"saqScreen\" class=\"ols-saq-screen\">\r\n          <section class=\"saq-question-area\">\r\n            <div class=\"saq-question-text\">\r\n              <strong>(ii)<\/strong>&nbsp;&nbsp; Melting temperature depends on the strength of metallic bonding.<br>\r\n              Explain why the metallic bonding in magnesium is much stronger than that in sodium.\r\n            <\/div>\r\n\r\n            <div class=\"saq-student-box\">\r\n              <span id=\"saqStudentText\"><\/span><span id=\"saqStudentCursor\" class=\"cursor\"><\/span>\r\n            <\/div>\r\n          <\/section>\r\n\r\n          <section id=\"saqTeacherFeedback\" class=\"saq-teacher-feedback\">\r\n            <span id=\"saqTeacherText\"><\/span><span id=\"saqTeacherCursor\" class=\"cursor saq-teacher-cursor\" style=\"display:none;\"><\/span>\r\n          <\/section>\r\n        <\/main>\r\n      <\/div>\r\n    <\/div>\r\n  <\/section>\r\n\r\n<\/div>\r\n\r\n<script>\r\n(function(){\r\n  const nativeSetTimeout=window.setTimeout.bind(window);\r\n  const nativeClearTimeout=window.clearTimeout.bind(window);\r\n  let nextTimerId=1;\r\n  let paused=false;\r\n  const timers=new Map();\r\n\r\n  function runTimer(timerId){\r\n    const timer=timers.get(timerId);\r\n\r\n    if(!timer || timer.cleared){\r\n      return;\r\n    }\r\n\r\n    timers.delete(timerId);\r\n    timer.callback();\r\n  }\r\n\r\n  window.setTimeout=function(callback,delay){\r\n    const timerId=nextTimerId++;\r\n    const safeDelay=Math.max(0,Number(delay) || 0);\r\n\r\n    const timer={\r\n      callback:callback,\r\n      delay:safeDelay,\r\n      remaining:safeDelay,\r\n      startedAt:Date.now(),\r\n      nativeId:null,\r\n      cleared:false\r\n    };\r\n\r\n    if(paused){\r\n      timer.startedAt=null;\r\n    }else{\r\n      timer.nativeId=nativeSetTimeout(function(){\r\n        runTimer(timerId);\r\n      },safeDelay);\r\n    }\r\n\r\n    timers.set(timerId,timer);\r\n    return timerId;\r\n  };\r\n\r\n  window.clearTimeout=function(timerId){\r\n    const timer=timers.get(timerId);\r\n\r\n    if(timer){\r\n      timer.cleared=true;\r\n\r\n      if(timer.nativeId!==null){\r\n        nativeClearTimeout(timer.nativeId);\r\n      }\r\n\r\n      timers.delete(timerId);\r\n      return;\r\n    }\r\n\r\n    nativeClearTimeout(timerId);\r\n  };\r\n\r\n  function pauseVideos(){\r\n    document.querySelectorAll(\"video\").forEach(function(video){\r\n      if(!video.paused && !video.ended){\r\n        video.dataset.olsWasPlaying=\"1\";\r\n        video.pause();\r\n      }\r\n    });\r\n  }\r\n\r\n  function resumeVideos(){\r\n    document.querySelectorAll(\"video\").forEach(function(video){\r\n      if(video.dataset.olsWasPlaying===\"1\"){\r\n        delete video.dataset.olsWasPlaying;\r\n\r\n        const playPromise=video.play();\r\n\r\n        if(playPromise!==undefined){\r\n          playPromise.catch(function(){});\r\n        }\r\n      }\r\n    });\r\n  }\r\n\r\n  function pauseAnimation(){\r\n    if(paused){\r\n      return \"paused\";\r\n    }\r\n\r\n    paused=true;\r\n    document.documentElement.classList.add(\"ols-animation-paused\");\r\n\r\n    timers.forEach(function(timer){\r\n      if(timer.nativeId!==null){\r\n        nativeClearTimeout(timer.nativeId);\r\n        timer.nativeId=null;\r\n      }\r\n\r\n      if(timer.startedAt!==null){\r\n        timer.remaining=Math.max(0,timer.delay-(Date.now()-timer.startedAt));\r\n        timer.startedAt=null;\r\n      }\r\n    });\r\n\r\n    pauseVideos();\r\n    return \"paused\";\r\n  }\r\n\r\n  function resumeAnimation(){\r\n    if(!paused){\r\n      return \"playing\";\r\n    }\r\n\r\n    paused=false;\r\n    document.documentElement.classList.remove(\"ols-animation-paused\");\r\n\r\n    timers.forEach(function(timer,timerId){\r\n      timer.startedAt=Date.now();\r\n      timer.delay=timer.remaining;\r\n      timer.nativeId=nativeSetTimeout(function(){\r\n        runTimer(timerId);\r\n      },timer.remaining);\r\n    });\r\n\r\n    resumeVideos();\r\n    return \"playing\";\r\n  }\r\n\r\n  window.olsToggleAnimationPause=function(){\r\n    if(paused){\r\n      return resumeAnimation();\r\n    }\r\n\r\n    return pauseAnimation();\r\n  };\r\n\r\n  window.olsPauseAnimation=pauseAnimation;\r\n  window.olsResumeAnimation=resumeAnimation;\r\n})();\r\n\r\nfunction typeWriter(target,text,speed,callback){\r\n  let i=0;\r\n\r\n  function typing(){\r\n    if(i<text.length){\r\n      const char=text.charAt(i);\r\n      target.textContent+=char;\r\n      i++;\r\n\r\n      let delay=speed;\r\n\r\n      if(char===\".\"){delay=speed*5;}\r\n      if(char===\",\"){delay=speed*2.5;}\r\n      if(char===\"\\n\"){delay=speed*4;}\r\n\r\n      setTimeout(typing,delay);\r\n    }else{\r\n      if(callback){callback();}\r\n    }\r\n  }\r\n\r\n  typing();\r\n}\r\n\r\nfunction switchScene(currentScene,nextScene,callback){\r\n  currentScene.classList.add(\"fade-out\");\r\n\r\n  setTimeout(function(){\r\n    currentScene.classList.remove(\"active\");\r\n    currentScene.classList.remove(\"fade-out\");\r\n    nextScene.classList.add(\"active\");\r\n\r\n    if(callback){callback();}\r\n  },850);\r\n}\r\n\r\nfunction fitVideoScreen(){\r\n  const baseWidth=1180;\r\n  const baseHeight=664;\r\n  const safePadding=24;\r\n  const availableWidth=window.innerWidth-safePadding;\r\n  const availableHeight=window.innerHeight-safePadding;\r\n  const scaleByWidth=availableWidth\/baseWidth;\r\n  const scaleByHeight=availableHeight\/baseHeight;\r\n  const finalScale=Math.min(scaleByWidth,scaleByHeight,1);\r\n  document.documentElement.style.setProperty(\"--ols-video-screen-scale\",finalScale.toFixed(4));\r\n}\r\n\r\nfunction fitMcqScreen(){\r\n  const baseWidth=1360;\r\n  const baseHeight=1130;\r\n  const safePadding=24;\r\n  const availableWidth=window.innerWidth-safePadding;\r\n  const availableHeight=window.innerHeight-safePadding;\r\n  const scaleByWidth=availableWidth\/baseWidth;\r\n  const scaleByHeight=availableHeight\/baseHeight;\r\n  const finalScale=Math.min(scaleByWidth,scaleByHeight,1);\r\n  document.documentElement.style.setProperty(\"--ols-mcq-screen-scale\",finalScale.toFixed(4));\r\n}\r\n\r\nfunction fitSaqScreen(){\r\n  const baseWidth=1360;\r\n  const baseHeight=965;\r\n  const safePadding=24;\r\n  const availableWidth=window.innerWidth-safePadding;\r\n  const availableHeight=window.innerHeight-safePadding;\r\n  const scaleByWidth=availableWidth\/baseWidth;\r\n  const scaleByHeight=availableHeight\/baseHeight;\r\n  const finalScale=Math.min(scaleByWidth,scaleByHeight,1);\r\n  document.documentElement.style.setProperty(\"--ols-saq-screen-scale\",finalScale.toFixed(4));\r\n}\r\n\r\nfunction fitAllScreens(){\r\n  fitVideoScreen();\r\n  fitMcqScreen();\r\n  fitSaqScreen();\r\n}\r\n\r\nwindow.addEventListener(\"resize\",fitAllScreens);\r\nwindow.addEventListener(\"orientationchange\",fitAllScreens);\r\nfitAllScreens();\r\n\r\nconst sceneVideo=document.getElementById(\"sceneVideo\");\r\nconst sceneMcq=document.getElementById(\"sceneMcq\");\r\nconst sceneSaq=document.getElementById(\"sceneSaq\");\r\n\r\nconst videoTitle=\"Online Chemistry Lessons\";\r\nconst videoTitleText=document.getElementById(\"videoTitleText\");\r\nconst videoTitleCursor=document.getElementById(\"videoTitleCursor\");\r\nconst videoTitleScreen=document.getElementById(\"videoTitleScreen\");\r\nconst videoScene=document.getElementById(\"videoScene\");\r\nconst lessonVideo=document.getElementById(\"lessonVideo\");\r\n\r\nlet videoFallbackTimer=null;\r\nlet videoSceneComplete=false;\r\n\r\nfunction playLessonVideo(){\r\n  lessonVideo.muted=true;\r\n  lessonVideo.currentTime=0;\r\n\r\n  const playPromise=lessonVideo.play();\r\n\r\n  if(playPromise!==undefined){\r\n    playPromise.catch(function(){\r\n      lessonVideo.muted=true;\r\n    });\r\n  }\r\n}\r\n\r\nfunction completeVideoScene(){\r\n  if(videoSceneComplete){return;}\r\n\r\n  videoSceneComplete=true;\r\n\r\n  if(videoFallbackTimer){\r\n    clearTimeout(videoFallbackTimer);\r\n  }\r\n\r\n  lessonVideo.pause();\r\n\r\n  setTimeout(function(){\r\n    switchScene(sceneVideo,sceneMcq,function(){\r\n      startMcqIntro();\r\n    });\r\n  },1400);\r\n}\r\n\r\nlessonVideo.addEventListener(\"ended\",function(){\r\n  lessonVideo.pause();\r\n  completeVideoScene();\r\n});\r\n\r\nfunction startVideoSection(){\r\n  fitVideoScreen();\r\n\r\n  setTimeout(function(){\r\n    typeWriter(videoTitleText,videoTitle,44,function(){\r\n      setTimeout(function(){\r\n        videoTitleCursor.style.display=\"none\";\r\n\r\n        setTimeout(function(){\r\n          videoTitleScreen.classList.add(\"hide\");\r\n\r\n          setTimeout(function(){\r\n            videoScene.classList.add(\"show\");\r\n\r\n            setTimeout(function(){\r\n              playLessonVideo();\r\n\r\n              videoFallbackTimer=setTimeout(function(){\r\n                completeVideoScene();\r\n              },45000);\r\n            },600);\r\n          },850);\r\n        },3000);\r\n      },250);\r\n    });\r\n  },700);\r\n}\r\n\r\nconst mcqIntroTitle=\"Multiple Choice Question Bank\";\r\nconst mcqSpecificFeedbackText=\"Na\u207a is small, but Cl\u207b is larger than F\u207b, so the ionic bonding is weaker than in NaF.\";\r\nconst mcqGeneralFeedbackText=\r\n\"Your answer is incorrect.\\n\\n\"+\r\n\"To determine which compound has the strongest ionic bonding, recall the key principle:\\n\\n\"+\r\n\"\u2022 Ionic bond strength increases when ionic radii are small, because the ions can get closer together.\\n\"+\r\n\"\u2022 Smaller ions \u2192 stronger electrostatic attraction \u2192 stronger ionic lattice.\\n\"+\r\n\"\u2022 Na\u207a (0.102 nm) is smaller than K\u207a (0.138 nm).\\n\"+\r\n\"\u2022 F\u207b (0.133 nm) is smaller than Cl\u207b (0.180 nm).\\n\\n\"+\r\n\"Therefore, the strongest ionic bonding occurs in the compound formed by the smallest cation and the smallest anion \u2192 sodium fluoride (NaF).\\n\\n\"+\r\n\"The correct answer is: sodium fluoride\";\r\n\r\nconst mcqIntroScreen=document.getElementById(\"mcqIntroScreen\");\r\nconst mcqIntroTitleText=document.getElementById(\"mcqIntroTitleText\");\r\nconst mcqIntroTitleCursor=document.getElementById(\"mcqIntroTitleCursor\");\r\nconst mcqScreen=document.getElementById(\"mcqScreen\");\r\nconst mcqWrongOption=document.getElementById(\"mcqWrongOption\");\r\nconst mcqSubmitButton=document.getElementById(\"mcqSubmitButton\");\r\nconst mcqSpecificFeedback=document.getElementById(\"mcqSpecificFeedback\");\r\nconst mcqCrossIcon=document.getElementById(\"mcqCrossIcon\");\r\nconst mcqSpecificText=document.getElementById(\"mcqSpecificText\");\r\nconst mcqSpecificCursor=document.getElementById(\"mcqSpecificCursor\");\r\nconst mcqGeneralFeedback=document.getElementById(\"mcqGeneralFeedback\");\r\nconst mcqGeneralText=document.getElementById(\"mcqGeneralText\");\r\nconst mcqGeneralCursor=document.getElementById(\"mcqGeneralCursor\");\r\n\r\nfunction selectMcqWrongOption(){\r\n  mcqWrongOption.classList.add(\"clicking\");\r\n\r\n  setTimeout(function(){\r\n    mcqWrongOption.classList.add(\"selected\");\r\n  },220);\r\n\r\n  setTimeout(function(){\r\n    mcqWrongOption.classList.remove(\"clicking\");\r\n  },850);\r\n}\r\n\r\nfunction clickMcqSubmit(){\r\n  mcqSubmitButton.classList.add(\"clicked\");\r\n\r\n  setTimeout(function(){\r\n    mcqSubmitButton.classList.remove(\"clicked\");\r\n  },240);\r\n}\r\n\r\nfunction showMcqSpecificFeedback(){\r\n  mcqSpecificFeedback.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    mcqCrossIcon.classList.add(\"show\");\r\n  },180);\r\n\r\n  setTimeout(function(){\r\n    mcqSpecificCursor.style.display=\"inline-block\";\r\n\r\n    typeWriter(mcqSpecificText,mcqSpecificFeedbackText,12,function(){\r\n      mcqSpecificCursor.style.display=\"none\";\r\n\r\n      setTimeout(function(){\r\n        showMcqGeneralFeedback();\r\n      },650);\r\n    });\r\n  },560);\r\n}\r\n\r\nfunction showMcqGeneralFeedback(){\r\n  mcqGeneralFeedback.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    mcqGeneralCursor.style.display=\"inline-block\";\r\n\r\n    typeWriter(mcqGeneralText,mcqGeneralFeedbackText,8,function(){\r\n      mcqGeneralCursor.style.display=\"none\";\r\n\r\n      setTimeout(function(){\r\n        switchScene(sceneMcq,sceneSaq,function(){\r\n          startSaqIntro();\r\n        });\r\n      },2600);\r\n    });\r\n  },600);\r\n}\r\n\r\nfunction startMcqAnimation(){\r\n  fitMcqScreen();\r\n  mcqScreen.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    selectMcqWrongOption();\r\n\r\n    setTimeout(function(){\r\n      clickMcqSubmit();\r\n\r\n      setTimeout(function(){\r\n        showMcqSpecificFeedback();\r\n      },620);\r\n    },1150);\r\n  },1300);\r\n}\r\n\r\nfunction startMcqIntro(){\r\n  fitMcqScreen();\r\n\r\n  setTimeout(function(){\r\n    typeWriter(mcqIntroTitleText,mcqIntroTitle,44,function(){\r\n      setTimeout(function(){\r\n        mcqIntroTitleCursor.style.display=\"none\";\r\n\r\n        setTimeout(function(){\r\n          mcqIntroScreen.classList.add(\"hide\");\r\n\r\n          setTimeout(function(){\r\n            startMcqAnimation();\r\n          },850);\r\n        },3000);\r\n      },250);\r\n    });\r\n  },700);\r\n}\r\n\r\nconst saqIntroTitle=\"Chemistry Specialist\\nMarked Exam Feedback\";\r\nconst saqStudentAnswer=\"Magnesium has stronger metallic bonding because it has more atoms packed together and melts at a higher temperature than sodium.\";\r\nconst saqTeacherFeedbackText=\r\n\"Comment:\\n\"+\r\n\"This answer is not correct. Melting temperature is a result of bonding strength, not the cause of it.\\n\\n\"+\r\n\"In metallic bonding, positive metal ions are attracted to a sea of delocalised electrons. The strength of this attraction depends on the charge of the ions and the number of delocalised electrons.\\n\\n\"+\r\n\"Magnesium forms Mg\u00b2\u207a ions and contributes two delocalised electrons per atom, whereas sodium forms Na\u207a ions and contributes only one electron. This results in a stronger electrostatic attraction in magnesium. Additionally, Mg\u00b2\u207a ions have a higher charge density than Na\u207a ions, further strengthening the metallic bonding.\\n\\n\"+\r\n\"Next time, include:\\n\"+\r\n\"\u2022 Ion charge: magnesium forms Mg\u00b2\u207a, sodium forms Na\u207a \u2713\\n\"+\r\n\"\u2022 Delocalised electrons: magnesium provides more electrons to the sea \u2713\\n\"+\r\n\"\u2022 Charge density: smaller, more highly charged ions create stronger attraction \u2713\\n\\n\"+\r\n\"You were close. Focus on explaining bonding in terms of charge and electron density rather than physical properties like melting point.\";\r\n\r\nconst saqIntro=document.getElementById(\"saqIntro\");\r\nconst saqIntroTitleText=document.getElementById(\"saqIntroTitleText\");\r\nconst saqIntroTitleCursor=document.getElementById(\"saqIntroTitleCursor\");\r\nconst saqStudentText=document.getElementById(\"saqStudentText\");\r\nconst saqTeacherText=document.getElementById(\"saqTeacherText\");\r\nconst saqStudentCursor=document.getElementById(\"saqStudentCursor\");\r\nconst saqTeacherCursor=document.getElementById(\"saqTeacherCursor\");\r\nconst saqFeedbackBox=document.getElementById(\"saqTeacherFeedback\");\r\nconst saqScreen=document.getElementById(\"saqScreen\");\r\n\r\nfunction startSaqFeedbackAnimation(){\r\n  fitSaqScreen();\r\n  saqScreen.classList.add(\"show\");\r\n\r\n  setTimeout(function(){\r\n    typeWriter(saqStudentText,saqStudentAnswer,27,function(){\r\n      saqStudentCursor.style.display=\"none\";\r\n\r\n      setTimeout(function(){\r\n        saqFeedbackBox.classList.add(\"show\");\r\n        saqTeacherCursor.style.display=\"inline-block\";\r\n\r\n        typeWriter(saqTeacherText,saqTeacherFeedbackText,10,function(){\r\n          saqTeacherCursor.style.display=\"none\";\r\n        });\r\n      },650);\r\n    });\r\n  },850);\r\n}\r\n\r\nfunction startSaqIntro(){\r\n  fitSaqScreen();\r\n\r\n  setTimeout(function(){\r\n    typeWriter(saqIntroTitleText,saqIntroTitle,44,function(){\r\n      setTimeout(function(){\r\n        saqIntroTitleCursor.style.display=\"none\";\r\n\r\n        setTimeout(function(){\r\n          saqIntro.classList.add(\"hide\");\r\n\r\n          setTimeout(function(){\r\n            startSaqFeedbackAnimation();\r\n          },850);\r\n        },3000);\r\n      },250);\r\n    });\r\n  },700);\r\n}\r\n\r\nstartVideoSection();\r\n<\/script>\r\n<\/body>\r\n<\/html>\r\n  <\/template>\r\n\r\n  <script>\r\n    (function(){\r\n      var startButton = document.getElementById(\"olsCourseAnimationStart001\");\r\n      var pauseButton = document.getElementById(\"olsCourseAnimationPause001\");\r\n      var iframe = document.getElementById(\"olsCourseAnimationFrame001\");\r\n      var template = document.getElementById(\"olsCourseAnimationTemplate001\");\r\n\r\n      if (!startButton || !pauseButton || !iframe || !template) {\r\n        return;\r\n      }\r\n\r\n      startButton.addEventListener(\"click\", function(){\r\n        iframe.setAttribute(\"srcdoc\", template.innerHTML);\r\n        startButton.classList.add(\"is-hidden\");\r\n        pauseButton.classList.add(\"is-visible\");\r\n        pauseButton.textContent = \"Pause\";\r\n        pauseButton.setAttribute(\"aria-label\", \"Pause course preview animation\");\r\n      });\r\n\r\n      pauseButton.addEventListener(\"click\", function(){\r\n        if (!iframe.contentWindow || typeof iframe.contentWindow.olsToggleAnimationPause !== \"function\") {\r\n          return;\r\n        }\r\n\r\n        var state = iframe.contentWindow.olsToggleAnimationPause();\r\n\r\n        if (state === \"paused\") {\r\n          pauseButton.textContent = \"Resume\";\r\n          pauseButton.setAttribute(\"aria-label\", \"Resume course preview animation\");\r\n        } else {\r\n          pauseButton.textContent = \"Pause\";\r\n          pauseButton.setAttribute(\"aria-label\", \"Pause course preview animation\");\r\n        }\r\n      });\r\n    })();\r\n  <\/script>\r\n<\/section>\n\n      <section class=\"ols-attribution-card\">\n        <p><strong>Copyright notice:<\/strong> This OLS revision content, including the explanations, layout, diagrams, tables and embedded learning structure, is authored for Online Learning System by Dr. Mohammed Al-Fatah. It may not be copied, reproduced, redistributed or adapted without written permission.<\/p>\n      <\/section>\n\n      <div class=\"ols-lightbox-overlay ols-polymer-waste-page-lb\" role=\"dialog\" aria-modal=\"true\" aria-label=\"Image lightbox\">\n        <button class=\"ols-lightbox-close\" type=\"button\" aria-label=\"Close lightbox\">&times;<\/button>\n        <img decoding=\"async\" class=\"ols-lightbox-img\" src=\"\" alt=\"\">\n      <\/div>\n\n      <script>\n      (function(){\n        var wrap = document.querySelector('.ols-polymer-waste-page');\n        if (!wrap) { return; }\n        var overlay = wrap.querySelector('.ols-lightbox-overlay');\n        var lbImg = wrap.querySelector('.ols-lightbox-img');\n        var closeBtn = wrap.querySelector('.ols-lightbox-close');\n        if (!overlay) { return; }\n        if (!lbImg) { return; }\n        var links = wrap.querySelectorAll('.ols-lightbox-link');\n        links.forEach(function(link){\n          link.addEventListener('click', function(e){\n            e.preventDefault();\n            var img = link.querySelector('img');\n            if (!img) { return; }\n            lbImg.src = img.src;\n            lbImg.alt = img.alt;\n            overlay.classList.add('is-open');\n            document.body.style.overflow = 'hidden';\n          });\n        });\n        function closeLightbox(){\n          overlay.classList.remove('is-open');\n          document.body.style.overflow = '';\n          lbImg.src = '';\n          lbImg.alt = '';\n        }\n        if (closeBtn) {\n          closeBtn.addEventListener('click', closeLightbox);\n        }\n        overlay.addEventListener('click', function(e){\n          if (e.target === overlay) { closeLightbox(); }\n        });\n        document.addEventListener('keydown', function(e){\n          if (e.key === 'Escape') { closeLightbox(); }\n        });\n      })();\n      <\/script>\n\n    <\/main>\n  \n\n<script type=\"application\/ld+json\">{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@graph\": [\n    {\n      \"@type\": \"Organization\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/#organization\",\n      \"name\": \"Online Learning System\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/\"\n    },\n    {\n      \"@type\": \"WebPage\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#webpage\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/\",\n      \"name\": \"Processing Waste Polymers - OCR A Level Chemistry A\",\n      \"headline\": \"Processing Waste Polymers\",\n      \"description\": \"OCR A Level Chemistry A 4.1.3(k) revision notes on processing waste polymers: combustion for energy production and use as an organic feedstock, with the benefits for sustainability.\",\n      \"inLanguage\": \"en-GB\",\n      \"isPartOf\": {\n        \"@type\": \"WebSite\",\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/#website\",\n        \"name\": \"Online Learning System\",\n        \"url\": \"https:\/\/www.onlinelearningsystem.net\/\"\n      },\n      \"publisher\": {\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/#organization\"\n      },\n      \"author\": {\n        \"@type\": \"Person\",\n        \"name\": \"Dr. Mohammed Al-Fatah\"\n      },\n      \"breadcrumb\": {\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#breadcrumb\"\n      },\n      \"mainEntity\": {\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#course\"\n      }\n    },\n    {\n      \"@type\": \"BreadcrumbList\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#breadcrumb\",\n      \"itemListElement\": [\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 1,\n          \"name\": \"Revision Notes\",\n          \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\"\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 2,\n          \"name\": \"A Level Chemistry\",\n          \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\"\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 3,\n          \"name\": \"OCR A\",\n          \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/\"\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 4,\n          \"name\": \"4.1.3 Alkenes\",\n          \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/\"\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 5,\n          \"name\": \"Processing Waste Polymers - OCR A Level Chemistry A\",\n          \"item\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/polymer-waste\/\"\n        }\n      ]\n    },\n    {\n      \"@type\": \"Course\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#course\",\n      \"name\": \"Processing Waste Polymers - OCR A Level Chemistry A\",\n      \"description\": \"Revision notes for OCR A Level Chemistry A section 4.1.3 Alkenes covering polymer waste disposal, incineration, recycling, biodegradable polymers, compostable polymers and cracking waste polymers into useful hydrocarbon feedstock.\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/\",\n      \"provider\": {\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/#organization\"\n      },\n      \"educationalLevel\": \"A Level\",\n      \"courseCode\": \"H432\/02\",\n      \"inLanguage\": \"en-GB\",\n      \"teaches\": [\n        \"Polymer waste disposal\",\n        \"Incineration of waste polymers\",\n        \"Removal of acidic gases using scrubbers\",\n        \"Recycling thermoplastic polymers\",\n        \"Biodegradable and compostable polymers\",\n        \"Cracking waste polymers\",\n        \"Environmental advantages and disadvantages of polymer disposal methods\"\n      ],\n      \"hasCourseInstance\": {\n        \"@type\": \"CourseInstance\",\n        \"courseMode\": \"online\",\n        \"courseWorkload\": \"Self-paced revision\"\n      }\n    },\n    {\n      \"@type\": \"ImageObject\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#incineration-image\",\n      \"name\": \"Incineration of Waste Polymers\",\n      \"description\": \"Image showing an incineration plant used to burn waste polymers, reducing waste volume while producing emissions that require pollution control.\",\n      \"contentUrl\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Incineration.webp\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Incineration.webp\"\n    },\n    {\n      \"@type\": \"ImageObject\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#recycling-image\",\n      \"name\": \"Recycling Waste Polymers\",\n      \"description\": \"Image showing a recycling facility where waste plastics are sorted and processed for reuse.\",\n      \"contentUrl\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Recycling.webp\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Recycling.webp\"\n    },\n    {\n      \"@type\": \"ImageObject\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#cracking-image\",\n      \"name\": \"Cracking Waste Polymers\",\n      \"description\": \"Image showing industrial cracking of waste polymers into smaller hydrocarbons that can be reused as chemical feedstock.\",\n      \"contentUrl\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Cracking.webp\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Cracking.webp\"\n    },\n    {\n      \"@type\": \"ItemList\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#related-lessons\",\n      \"name\": \"Related Alkene Revision Notes\",\n      \"itemListElement\": [\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 1,\n          \"item\": {\n            \"@type\": \"Course\",\n            \"name\": \"Polymerisation Reactions\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/polymerisation-reactions\/\",\n            \"description\": \"Revision notes covering addition polymerisation, monomers, repeat units and polymer formation from alkenes.\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 2,\n          \"item\": {\n            \"@type\": \"Course\",\n            \"name\": \"Reactions of Alkenes\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/reactions-of-alkenes\/\",\n            \"description\": \"Revision notes covering key addition reactions of alkenes including halogenation, hydrogenation and hydration.\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 3,\n          \"item\": {\n            \"@type\": \"Course\",\n            \"name\": \"Alkene Bonding\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/alkene-bonding\/\",\n            \"description\": \"Revision notes covering alkene structure, carbon-carbon double bonds, sigma bonds, pi bonds and alkene reactivity.\"\n          }\n        }\n      ]\n    },\n    {\n      \"@type\": \"FAQPage\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/processing-waste-polymers\/#faq\",\n      \"mainEntity\": [\n        {\n          \"@type\": \"Question\",\n          \"name\": \"What are the main methods of disposing of waste polymers?\",\n          \"acceptedAnswer\": {\n            \"@type\": \"Answer\",\n            \"text\": \"The main methods include incineration, recycling, use of biodegradable or compostable polymers, and cracking waste polymers into smaller hydrocarbon molecules.\"\n          }\n        },\n        {\n          \"@type\": \"Question\",\n          \"name\": \"What is an advantage and disadvantage of incinerating waste polymers?\",\n          \"acceptedAnswer\": {\n            \"@type\": \"Answer\",\n            \"text\": \"Incineration can generate energy and greatly reduce the volume of waste, but it can also release toxic substances and greenhouse gases.\"\n          }\n        },\n        {\n          \"@type\": \"Question\",\n          \"name\": \"Why are thermoplastics suitable for recycling by melting?\",\n          \"acceptedAnswer\": {\n            \"@type\": \"Answer\",\n            \"text\": \"Thermoplastic polymers can be heated, reshaped and reformed without undergoing chemical change, making them suitable for recycling by melting.\"\n          }\n        },\n        {\n          \"@type\": \"Question\",\n          \"name\": \"Why can cracking waste polymers be useful?\",\n          \"acceptedAnswer\": {\n            \"@type\": \"Answer\",\n            \"text\": \"Cracking breaks long polymer chains into smaller hydrocarbon molecules that can be reused as feedstock to manufacture new chemicals and polymers.\"\n          }\n        }\n      ]\n    }\n  ]\n}<\/script>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Revision Notes \/ A Level Chemistry \/ OCR A \/ 4.1.3 Alkenes \/ Processing Waste Polymers Processing Waste Polymers A concise OCR A Level Chemistry A revision guide to the two ways waste polymers are processed for sustainability in 4.1.3(k): combustion for energy production, and use as an organic feedstock for making new plastics and [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":7119,"menu_order":6,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-7306","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/7306","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/users\/12"}],"replies":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/comments?post=7306"}],"version-history":[{"count":0,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/7306\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/7119"}],"wp:attachment":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/media?parent=7306"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}