{"id":10907,"date":"2026-09-26T21:56:46","date_gmt":"2026-09-26T20:56:46","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/"},"modified":"2026-10-04T23:03:45","modified_gmt":"2026-10-04T22:03:45","slug":"reaction-types-mechanisms-and-nucleophiles","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/","title":{"rendered":"Reaction Types, Mechanisms and Nucleophiles"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-alcohols-halogenoalkanes-spectra-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      --gold: #c9973a;\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\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 { transition: color 0.2s ease, text-decoration-color 0.2s ease; }\n    .ols-breadcrumbs a:hover { color: var(--blue); text-decoration: underline; text-underline-offset: 3px; }\n    .ols-title-card, .ols-note-card, .ols-h5p-card, .ols-related-card { background: #ffffff; border: 1px solid var(--border); border-radius: 28px; box-shadow: var(--shadow); padding: 34px; margin-bottom: 24px; overflow: hidden; }\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    .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-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-note-card p, .ols-note-card li, .ols-h5p-card p, .ols-related-card p { font-size: clamp(15px, 1.25vw, 17px); line-height: 1.65; font-weight: 300; color: var(--body-text); }\n    .ols-note-card strong, .ols-h5p-card strong, .ols-related-card strong, .ols-faq-card strong { font-weight: 750; color: var(--navy); }\n    .ols-note-card ul { margin: 0; padding-left: 22px; }\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-figure-card { margin: 26px 0 4px; border: 1px solid var(--border); border-radius: 26px; overflow: hidden; background: #ffffff; box-shadow: var(--inner-shadow); }\n    .ols-figure-image { width: 100%; min-height: 390px; background-color: #ffffff; background-image: var(--ols-image); background-repeat: no-repeat; background-position: center; background-size: contain; border-bottom: 1px solid var(--border); }\n    .ols-figure-caption { padding: 22px 26px 24px; background: linear-gradient(135deg, #ffffff, #f8fbff); }\n    .ols-figure-caption h3 { margin: 0 0 8px; color: var(--navy); font-size: clamp(21px, 2vw, 30px); line-height: 1.25; font-weight: 800; font-style: italic; }\n    .ols-figure-caption p { margin: 0; color: #5f6b85; font-size: clamp(16px, 1.4vw, 19px); line-height: 1.65; font-weight: 300; font-style: italic; }\n    .ols-table-wrap { overflow-x: auto; border-radius: 22px; border: 1px solid var(--border); background: #ffffff; margin-top: 18px; }\n    .ols-table { width: 100%; border-collapse: collapse; min-width: 680px; }\n    .ols-table th { background: var(--navy); color: #ffffff; padding: 14px 16px; text-align: left; font-size: 15px; font-weight: 700; }\n    .ols-table td { padding: 14px 16px; border-bottom: 1px solid var(--border); font-size: 15px; color: var(--body-text); vertical-align: top; }\n    .ols-table tr:last-child td { border-bottom: none; }\n    .ols-definition-box { background: linear-gradient(135deg, #ffffff, var(--soft-purple)); border: 2px dashed rgba(122, 62, 157, 0.35); border-radius: 24px; padding: 26px; margin-top: 22px; display: grid; grid-template-columns: 1fr; gap: 16px; align-items: center; }\n    .ols-definition-circle { width: 105px; height: 105px; border-radius: 50%; background: linear-gradient(135deg, #9b59b6, #6f3d96); color: white; display: grid; place-items: center; font-size: 28px; font-weight: 800; text-align: center; margin: 0 auto; }\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    .ols-infographic-full { width: 100%; margin: 6px 0 30px; }\n    .ols-infographic-full-frame { width: 100%; border-radius: 22px; overflow: hidden; box-shadow: 0 18px 42px rgba(28, 36, 75, 0.13); background: #ffffff; }\n    .ols-infographic-full-frame img { width: 100%; height: auto; display: block; }\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    .ols-unlock { background: linear-gradient(135deg, var(--navy), #0f4fa8); border-radius: 30px; padding: 36px; color: #ffffff; box-shadow: var(--shadow); text-align: center; margin: 30px 0 24px; }\n    .ols-unlock h2 { margin: 0 0 12px; font-size: clamp(30px, 4vw, 46px); line-height: 1.15; font-weight: 800; color: #ffffff; text-align: center; }\n    .ols-unlock p { margin: 0 auto 24px; max-width: 700px; font-size: 20px; line-height: 1.6; font-weight: 300; text-align: center; color: #ffffff; }\n    .ols-cta-button { display: inline-flex; align-items: center; justify-content: center; padding: 14px 26px; border-radius: 999px; background: #ffffff; color: var(--navy); text-decoration: none; font-weight: 700; }\n\n    @media (max-width: 1050px) {\n      .ols-main { max-width: none; }\n      .ols-related-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }\n    }\n\n    @media (max-width: 760px) {\n      .ols-title-card, .ols-note-card, .ols-h5p-card, .ols-related-card, .ols-unlock { padding: 24px 18px; border-radius: 22px; }\n      .ols-note-title { align-items: flex-start; }\n      .ols-figure-card { border-radius: 22px; }\n      .ols-figure-image { min-height: 250px; }\n      .ols-figure-caption { padding: 18px; }\n      .ols-topic-list, .ols-related-grid { grid-template-columns: 1fr; }\n      .ols-infographic-full { margin: 0 0 26px; }\n      .ols-infographic-full-frame { border-radius: 18px; }\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      .ols-note-card h3 { margin: 22px 0 8px; font-size: 18px; line-height: 1.25; font-weight: 500; color: var(--navy); }\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\n    \/* inline checks (H5P re-flow, Sep 2026) *\/\n    .ols-h5p-card.ols-h5p-inline { padding: 26px 28px; border-left: 6px solid #7c3aed; }\n    .ols-h5p-card.ols-h5p-inline h2 { font-size: clamp(20px, 2.2vw, 27px); letter-spacing: -0.02em; }\n    .ols-h5p-card.ols-h5p-inline > p { margin: 8px 0 0; }\n    .ols-h5p-card.ols-h5p-inline .ols-h5p-frame { margin-top: 16px; padding: 14px; border-radius: 20px; }\n    .ols-h5p-kicker { display: inline-block; margin-bottom: 10px; padding: 5px 12px; border-radius: 999px; background: #ede9fe; color: #5b21b6; font-size: 12px; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase; }\n    .ols-h5p-card.ols-h5p-recap { border-left-color: #c9973a; background: linear-gradient(135deg, #ffffff 0%, #fff8e8 100%); }\n    .ols-h5p-recap .ols-h5p-kicker { background: #fdf0d2; color: #8a5a00; }\n    @media (max-width: 760px) { .ols-h5p-card.ols-h5p-inline { padding: 20px 16px; } }\n\n.ols-faq-card,\n    .ols-quicksnap-card {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 28px;\n      box-shadow: var(--shadow);\n      padding: 34px;\n      margin-bottom: 24px;\n      overflow: hidden;\n    }\n.ols-faq-card h2,\n    .ols-quicksnap-card h2,\n    .ols-infographic-title {\n      margin: 0;\n      font-size: clamp(28px, 3.5vw, 42px);\n      line-height: 1.15;\n      font-weight: 800;\n      color: #111827;\n      letter-spacing: -0.03em;\n    }\n.ols-faq-card h2,\n    .ols-quicksnap-card h2 {\n      margin-bottom: 14px;\n    }\n.ols-faq-card p,\n    .ols-quicksnap-card p {\n      font-size: clamp(15px, 1.25vw, 17px);\n      line-height: 1.65;\n      font-weight: 300;\n      color: var(--body-text);\n    }\n.ols-faq-card strong,\n    .ols-quicksnap-card strong {\n      font-weight: 700;\n      color: var(--navy);\n    }\n.ols-faq-list {\n      display: grid;\n      gap: 14px;\n      margin-top: 18px;\n    }\n.ols-faq-item {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 18px;\n      padding: 18px 20px;\n      box-shadow: var(--inner-shadow);\n    }\n.ols-faq-item h3 {\n      margin: 0 0 8px;\n      font-size: 20px;\n      line-height: 1.3;\n      color: var(--navy);\n    }\n.ols-faq-item p {\n      margin: 0;\n      font-size: 16px;\n      line-height: 1.65;\n      color: var(--body-text);\n    }\n.ols-faq-card,\n      .ols-quicksnap-card,\n      .ols-attribution-card {\n        padding: 24px 18px;\n        border-radius: 22px;\n      }\n  <\/style>\n\n    <aside class=\"ols-sidebar\">\n  <div class=\"ols-sidebar-header\">\n    <h3>Revision Notes<\/h3>\n    <p>A Level Chemistry<\/p>\n  <\/div>\n\n  <div class=\"ols-topic-group\">\n    <h4>Topic 10 Alcohols, Halogenoalkanes &amp; Spectra<\/h4>\n\n    <ul class=\"ols-topic-list\">\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/\">Topic 10 Overview<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10a-alcohols\/\">Topic 10A Alcohols<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10a-alcohols\/alcohols-naming-classification-and-properties\/\">Alcohols: Naming, Classification and Properties<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10a-alcohols\/oxidation-of-alcohols\/\">Oxidation of Alcohols<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10a-alcohols\/reactions-of-alcohols\/\">Substitution and Elimination Reactions of Alcohols<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10a-alcohols\/preparing-and-purifying-organic-liquids\/\">Preparing and Purifying Organic Liquids<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-6-chlorination-of-2-methylpropan-2-ol\/\">Core Practical 6<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-7-oxidation-of-propan-1-ol\/\">Core Practical 7<\/a>\n          <\/li>\n        <\/ul>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/\">Topic 10B Halogenoalkanes<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/\">Reaction Types, Mechanisms and Nucleophiles<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/halogenoalkanes-naming-classification-and-bonding\/\">Halogenoalkanes: Naming, Classification and the C\u2013X Bond<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/nucleophilic-substitution-reactions\/\">Nucleophilic Substitution Reactions<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/elimination-reactions-of-halogenoalkanes\/\">Elimination Reactions of Halogenoalkanes<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/rates-of-hydrolysis-and-bond-enthalpy\/\">Rates of Hydrolysis and Bond Enthalpy<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-5-hydrolysis-of-halogenoalkanes\/\">Core Practical 5<\/a>\n          <\/li>\n        <\/ul>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10c-spectra\/\">Topic 10C Spectra<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10c-spectra\/mass-spectra-of-organic-compounds\/\">Mass Spectra of Organic Compounds<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10c-spectra\/infrared-spectroscopy\/\">Infrared Spectroscopy<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10c-spectra\/identifying-unknown-compounds\/\">Identifying Unknown Compounds<\/a>\n          <\/li>\n          <li>\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-8-analysis-of-inorganic-and-organic-unknowns\/\">Core Practical 8<\/a>\n          <\/li>\n        <\/ul>\n      <\/li>\n    <\/ul>\n  <\/div>\n\n  <div class=\"ols-topic-group\">\n    <h4>Other Topics<\/h4>\n\n    <ul class=\"ols-topic-list\">\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/\">Topic 4 Organic Chemistry &amp; Alkanes<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-5-alkenes\/\">Topic 5 Alkenes<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-9-kinetics-and-equilibria\/\">Topic 9 Kinetics &amp; Equilibria<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/\">Core Practicals<\/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>\r\n\n\n    <main class=\"ols-main\">\n\n      <!-- BREADCRUMBS - updated with full path and correct links -->\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\/edexcel-international\/\">Edexcel International<\/a> \/\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/\">Topic 10 Alcohols, Halogenoalkanes and Spectra<\/a> \/\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/\">Topic 10B Halogenoalkanes<\/a> \/\n<span>Reaction Types, Mechanisms and Nucleophiles<\/span>\n<\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Reaction Types, Mechanisms and Nucleophiles<\/h1>\n        <p class=\"ols-page-intro\">A concise revision guide to classifying organic reactions as addition, elimination, substitution, oxidation, reduction, hydrolysis or polymerisation, what a mechanism and a curly arrow show, heterolytic bond breaking, electrophiles and nucleophiles, and how bond polarity decides the mechanism.<\/p>\n        <div class=\"ols-badges\">\n<div class=\"ols-badge\">Exam board: Edexcel International<\/div>\n<div class=\"ols-badge\">Unit 2: WCH12\/01<\/div>\n<div class=\"ols-badge\">Topic 10B Halogenoalkanes<\/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: Organic Reactions<\/h2>\n<p>Three quick questions on what you already know: addition across a double bond, what a catalyst does, and what happens when a polymer forms.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-content\" data-content-id=\"946\"><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">1<\/div>\n<h2>Classifying Organic Reactions<\/h2>\n<\/div>\n<p>Organic reactions are sorted into a small number of <strong>reaction types<\/strong> according to what happens to the molecule.<\/p><p>In an <strong>addition<\/strong> reaction two molecules join to form one, and a double bond is used up: ethene and bromine give 1,2-dibromoethane.<\/p><p>In an <strong>elimination<\/strong> reaction a small molecule is removed and a double bond forms.<\/p><p>In a <strong>substitution<\/strong> reaction one atom or group is replaced by another, and the number of groups on the carbon stays the same.<\/p>\n<p><strong>Oxidation<\/strong> is the gain of oxygen or the loss of hydrogen, written with [O]; <strong>reduction<\/strong> is the reverse, written with [H].<\/p><p><strong>Hydrolysis<\/strong> is the splitting of a molecule by reaction with water, or with hydroxide ions, so the hydrolysis of a halogenoalkane is also a substitution.<\/p><p><strong>Polymerisation<\/strong> joins many small molecules into a long chain.<\/p><p>A reaction can belong to two classes at once: elimination and substitution describe what happens to the organic molecule, while nucleophilic or electrophilic describes how.<\/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\/alcohols-halogenoalkanes-spectra-reactiontypes.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\/alcohols-halogenoalkanes-spectra-reactiontypes.jpg\" alt=\"Table of organic reaction types with definitions and examples, and heterolytic versus homolytic bond breaking\" data-fullscreen-src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/alcohols-halogenoalkanes-spectra-reactiontypes.jpg\">\n<\/a>\n<\/div>\n<div class=\"ols-figure-caption\"><p>The seven reaction types with a definition and an example equation for each, and the two ways a covalent bond can break.<\/p><\/div>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Key idea:<\/strong> Ask two questions: has the number of molecules changed (addition or elimination) and has a group been swapped (substitution)? Then check whether oxygen or hydrogen has been gained or lost.<\/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>Check: Naming the Reaction Type<\/h2>\n<p>Classify reactions that are not the examples on this page.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-947\" class=\"h5p-iframe\" data-content-id=\"947\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Alcohols, Halogenoalkanes and Spectra Drag: Naming the Reaction Type\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">2<\/div>\n<h2>What a Mechanism Is<\/h2>\n<\/div>\n<p>A <strong>reaction mechanism<\/strong> is a description of the steps by which the reactants become the products, showing which bonds break, which bonds form, and in what order.<\/p><p>An overall equation says only what goes in and what comes out; the mechanism explains why the conditions matter, why some compounds react faster than others, and why the products are what they are.<\/p>\n<p>Mechanisms are drawn with <strong>curly arrows<\/strong>. A full curly arrow shows the movement of a pair of electrons.<\/p><p>It always starts from where the electrons are, a lone pair or the middle of a bond, and ends where they go, a new bond or an atom that becomes negatively charged.<\/p><div class=\"ols-key-box\"><p><strong>Exam focus:<\/strong> The arrows are the answer; a mechanism with the right products but the arrows starting from the wrong place scores no marks.<\/p><\/div>\n<div class=\"ols-key-box\">\n<p><strong>Definition:<\/strong> A curly arrow starts at a lone pair or a covalent bond and ends where a new bond forms or where the electrons come to rest as a charge.<\/p>\n<\/div>\n<\/article>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">3<\/div>\n<h2>Heterolytic Bond Breaking: Electrophiles and Nucleophiles<\/h2>\n<\/div>\n<p>A covalent bond can break in two ways. In <strong>homolytic fission<\/strong> each atom keeps one electron and two radicals form; this is what happens to chlorine in ultraviolet light in the reactions of alkanes.<\/p><p>In <strong>heterolytic fission<\/strong> both electrons of the bond go to one atom, so a positive ion and a negative ion form. Heterolytic fission produces the two kinds of reactive species that drive most organic mechanisms.<\/p>\n<p>An <strong>electrophile<\/strong> is an electron-pair acceptor: a species with a positive charge or a \u03b4+ atom that is attacked by electron-rich centres.<\/p><p>A <strong>nucleophile<\/strong> is an electron-pair donor: a species with a lone pair of electrons, and often a negative charge, that attacks an electron-deficient, \u03b4+ atom.<\/p><p>Hydroxide ions, cyanide ions, water and ammonia are all nucleophiles because each has a lone pair to donate.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Species<\/th><th>Lone pair on<\/th><th>Charge<\/th><th>Role<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>OH\u207b<\/strong><\/td><td>oxygen<\/td><td>negative<\/td><td>nucleophile<\/td><\/tr>\n<tr><td><strong>CN\u207b<\/strong><\/td><td>carbon<\/td><td>negative<\/td><td>nucleophile<\/td><\/tr>\n<tr><td><strong>H\u2082O<\/strong><\/td><td>oxygen<\/td><td>neutral, \u03b4\u2212<\/td><td>nucleophile (weak)<\/td><\/tr>\n<tr><td><strong>NH\u2083<\/strong><\/td><td>nitrogen<\/td><td>neutral<\/td><td>nucleophile<\/td><\/tr>\n<tr><td><strong>H\u207a, Br\u207a (\u03b4+ end of Br\u2082)<\/strong><\/td><td>none<\/td><td>positive<\/td><td>electrophile<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Exam wording:<\/strong> Nucleophile: &#8220;an electron-pair donor&#8221; or &#8220;a species with a lone pair that attacks a \u03b4+ carbon&#8221;. Both are accepted; &#8220;negative ion&#8221; is not, because water and ammonia are nucleophiles without a charge.<\/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>Check: Electrophile or Nucleophile?<\/h2>\n<p>Sort species that are not in the table above.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-948\" class=\"h5p-iframe\" data-content-id=\"948\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Alcohols, Halogenoalkanes and Spectra Summary: Electrophile or Nucleophile?\"><\/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>Bond Polarity Decides the Mechanism<\/h2>\n<\/div>\n<p>The type of mechanism a compound undergoes follows from the <strong>polarity of its bonds<\/strong>.<\/p><p>An alkene has a non-polar C=C bond whose \u03c0 electrons are exposed and electron-rich, so it is attacked by electrophiles: alkenes undergo <strong>electrophilic addition<\/strong>.<\/p><p>A halogenoalkane has a polar C\u2013X bond, because the halogen is more electronegative than carbon, so the carbon is \u03b4+ and electron-deficient: halogenoalkanes are attacked by nucleophiles and undergo <strong>nucleophilic substitution<\/strong>.<\/p><p>An alkane has only non-polar C\u2013C and C\u2013H bonds, so neither electrophiles nor nucleophiles attack it, and its only reactions are radical reactions started by ultraviolet light.<\/p>\n<p>This is the link the specification wants: look at the bond, decide which end is electron-rich and which is electron-poor, and that tells you which kind of species attacks and where.<\/p>\n<div class=\"ols-key-box\">\n<p><strong>Key idea:<\/strong> Electron-rich C=C attracts electrophiles; electron-poor \u03b4+ carbon in C\u2013X attracts nucleophiles; non-polar C\u2013H and C\u2013C only react with radicals.<\/p>\n<\/div>\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\/alcohols-halogenoalkanes-spectra-polaritymech.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\/alcohols-halogenoalkanes-spectra-polaritymech.jpg\" alt=\"Three-column grid linking alkanes, alkenes and halogenoalkanes to radicals, electrophiles and nucleophiles.\" data-fullscreen-src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/alcohols-halogenoalkanes-spectra-polaritymech.jpg\">\n<\/a>\n<\/div>\n<div class=\"ols-figure-caption\"><p>Look at the bond first: an electron-rich C=C attracts electrophiles, a \u03b4+ carbon in a polar C\u2013X bond attracts nucleophiles, and non-polar alkanes react only with radicals.<\/p><\/div>\n<\/div>\n<\/article>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">5<\/div>\n<h2>Common Exam Points<\/h2>\n<\/div>\n<h3>Say<\/h3><p>&#8220;Substitution: the Br is replaced by OH.&#8221; &#8220;Heterolytic fission: both electrons go to the more electronegative atom.&#8221; &#8220;Nucleophile: electron-pair donor with a lone pair.&#8221;<\/p>\n<h3>Do not say<\/h3><p>&#8220;Hydrolysis is a reaction with acid.&#8221; &#8220;A nucleophile is attracted to the nucleus.&#8221; &#8220;The arrow shows where the atom moves&#8221; (it shows electrons).<\/p>\n<h3>Watch for<\/h3><p>Reaction types are asked with the reagent: &#8220;ethanolic KOH gives an elimination; aqueous KOH gives a substitution&#8221;.<\/p>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Check: Predicting the Mechanism Type<\/h2>\n<p>Link bond polarity to mechanism for molecules not discussed above.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-949\" class=\"h5p-iframe\" data-content-id=\"949\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Alcohols, Halogenoalkanes and Spectra Explain: Predicting the Mechanism Type\"><\/iframe><\/div><\/div>\n<\/section>\n<section class=\"ols-faq-card\">\n<h2>FAQs<\/h2>\n<p>Use these quick answers to check the reaction-type and mechanism vocabulary.<\/p>\n\n<div class=\"ols-faq-list\">\n<div class=\"ols-faq-item\">\n<h3>Can a reaction be both substitution and hydrolysis?<\/h3>\n<p>Yes. When a halogenoalkane reacts with water or hydroxide ions the halogen is swapped for OH (substitution) and the molecule is split by water (hydrolysis). Both names are correct.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>What is the difference between a nucleophile and a base?<\/h3>\n<p>Both donate a lone pair. A nucleophile donates it to a \u03b4+ carbon and forms a bond to carbon; a base donates it to a hydrogen and removes a proton. The hydroxide ion can do either, depending on the solvent.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>Where does a curly arrow start?<\/h3>\n<p>At the electrons that are moving: a lone pair or the middle of a covalent bond. It ends where a new bond forms or where the electrons come to rest as a negative charge.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>Why are alkanes attacked by neither electrophiles nor nucleophiles?<\/h3>\n<p>Their C\u2013C and C\u2013H bonds are almost non-polar, so there is no electron-rich or electron-poor site to attack. Only radicals, formed by UV light, react with them.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>What is the difference between homolytic and heterolytic fission?<\/h3>\n<p>Homolytic fission gives one electron to each atom, forming two radicals. Heterolytic fission gives both electrons to one atom, forming a positive and a negative ion.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<section class=\"ols-related-card\">\n<h2>Related Topic 10B Halogenoalkanes Pages<\/h2>\n<p>Use these pages to connect the ideas across halogenoalkanes and the rest of Topic 10.<\/p>\n<div class=\"ols-related-grid\">\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/halogenoalkanes-naming-classification-and-bonding\/\">Halogenoalkanes: Naming, Classification and the C\u2013X Bond<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/nucleophilic-substitution-reactions\/\">Nucleophilic Substitution Reactions<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/elimination-reactions-of-halogenoalkanes\/\">Elimination Reactions of Halogenoalkanes<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/rates-of-hydrolysis-and-bond-enthalpy\/\">Rates of Hydrolysis and Bond Enthalpy<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/\">Topic 10B Halogenoalkanes Overview<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-4-organic-chemistry-and-alkanes\/\">Topic 4 Organic Chemistry and Alkanes<\/a>\n<\/div>\n<\/section>\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    <\/main>\n  \n\n<script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@graph\": [\n    {\n      \"@type\": \"WebPage\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/#webpage\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/\",\n      \"name\": \"Reaction Types, Mechanisms and Nucleophiles | Topic 10B Halogenoalkanes | Online Learning System\",\n      \"description\": \"Edexcel International A Level Chemistry revision notes on organic reaction types and mechanisms: addition, elimination, substitution, oxidation, reduction, hydrolysis, polymerisation, curly arrows, heterolytic fission, electrophiles, nucleophiles and bond polarity.\",\n      \"isPartOf\": {\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/#website\"\n      },\n      \"breadcrumb\": {\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/#breadcrumb\"\n      }\n    },\n    {\n      \"@type\": \"WebSite\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/#website\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/\",\n      \"name\": \"Online Learning System\"\n    },\n    {\n      \"@type\": \"BreadcrumbList\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/#breadcrumb\",\n      \"itemListElement\": [\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 1,\n          \"item\": {\n            \"@type\": \"WebPage\",\n            \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\",\n            \"name\": \"Revision Notes\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 2,\n          \"item\": {\n            \"@type\": \"WebPage\",\n            \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\",\n            \"name\": \"A Level Chemistry\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 3,\n          \"item\": {\n            \"@type\": \"WebPage\",\n            \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\",\n            \"name\": \"Edexcel International\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 4,\n          \"item\": {\n            \"@type\": \"WebPage\",\n            \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/\",\n            \"name\": \"Topic 10 Alcohols, Halogenoalkanes and Spectra\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 5,\n          \"item\": {\n            \"@type\": \"WebPage\",\n            \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/\",\n            \"name\": \"Topic 10B Halogenoalkanes\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 6,\n          \"item\": {\n            \"@type\": \"WebPage\",\n            \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/\",\n            \"name\": \"Reaction Types, Mechanisms and Nucleophiles\"\n          }\n        }\n      ]\n    },\n    {\n      \"@type\": \"Course\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/#course\",\n      \"name\": \"Reaction Types, Mechanisms and Nucleophiles\",\n      \"description\": \"Edexcel International A Level Chemistry revision notes on organic reaction types and mechanisms: addition, elimination, substitution, oxidation, reduction, hydrolysis, polymerisation, curly arrows, heterolytic fission, electrophiles, nucleophiles and bond polarity.\",\n      \"provider\": {\n        \"@type\": \"Organization\",\n        \"name\": \"Online Learning System\",\n        \"url\": \"https:\/\/www.onlinelearningsystem.net\/\"\n      },\n      \"educationalLevel\": \"A Level\",\n      \"about\": [\n        \"Alcohols\",\n        \"Halogenoalkanes\",\n        \"Nucleophilic substitution\",\n        \"Elimination\",\n        \"Oxidation of alcohols\",\n        \"Mass spectrometry\",\n        \"Infrared spectroscopy\",\n        \"Organic chemistry\"\n      ],\n      \"hasCourseInstance\": {\n        \"@type\": \"CourseInstance\",\n        \"courseMode\": \"Online\"\n      }\n    },\n    {\n      \"@type\": \"ItemList\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/reaction-types-mechanisms-and-nucleophiles\/#relatedtopics\",\n      \"name\": \"Related Topic 10B Halogenoalkanes Pages\",\n      \"itemListElement\": [\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 1,\n          \"item\": {\n            \"@type\": \"Course\",\n            \"name\": \"Halogenoalkanes: Naming, Classification and the C\u2013X Bond\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/halogenoalkanes-naming-classification-and-bonding\/\",\n            \"description\": \"Edexcel International A Level Chemistry revision notes on halogenoalkanes: nomenclature and formulae, primary, secondary and tertiary, the polar carbon\u2013halogen bond, bond enthalpies and uses.\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 2,\n          \"item\": {\n            \"@type\": \"Course\",\n            \"name\": \"Nucleophilic Substitution Reactions\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/nucleophilic-substitution-reactions\/\",\n            \"description\": \"Edexcel International A Level Chemistry revision notes on nucleophilic substitution of halogenoalkanes: hydroxide, water, ammonia and cyanide as nucleophiles, conditions, products and the curly-arrow mechanism.\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 3,\n          \"item\": {\n            \"@type\": \"Course\",\n            \"name\": \"Elimination Reactions of Halogenoalkanes\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/elimination-reactions-of-halogenoalkanes\/\",\n            \"description\": \"Edexcel International A Level Chemistry revision notes on elimination of halogenoalkanes: ethanolic KOH, hydroxide as a base, alkene products and isomers, substitution versus elimination.\"\n          }\n        },\n        {\n          \"@type\": \"ListItem\",\n          \"position\": 4,\n          \"item\": {\n            \"@type\": \"Course\",\n            \"name\": \"Rates of Hydrolysis and Bond Enthalpy\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-10-alcohols-halogenoalkanes-and-spectra\/10b-halogenoalkanes\/rates-of-hydrolysis-and-bond-enthalpy\/\",\n            \"description\": \"Edexcel International A Level Chemistry revision notes on rates of hydrolysis of halogenoalkanes: the silver nitrate experiment, precipitate colours, bond enthalpy trend for C\u2013Cl, C\u2013Br and C\u2013I, and primary, secondary and tertiary comparison.\"\n          }\n        }\n      ]\n    }\n  ]\n}\n<\/script>\n\n<\/section>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Revision Notes \/ A Level Chemistry \/ Edexcel International \/ Topic 10 Alcohols, Halogenoalkanes and Spectra \/ Topic 10B Halogenoalkanes \/ Reaction Types, Mechanisms and Nucleophiles Reaction Types, Mechanisms and Nucleophiles A concise revision guide to classifying organic reactions as addition, elimination, substitution, oxidation, reduction, hydrolysis or polymerisation, what a mechanism and a curly arrow [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":10901,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-10907","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/10907","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=10907"}],"version-history":[{"count":2,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/10907\/revisions"}],"predecessor-version":[{"id":14189,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/10907\/revisions\/14189"}],"up":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/10901"}],"wp:attachment":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/media?parent=10907"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}