{"id":4961,"date":"2026-03-10T10:12:32","date_gmt":"2026-06-04T04:41:54","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/cp-6-chlorination-of-2-methylpropan-2-ol\/"},"modified":"2026-06-10T10:48:27","modified_gmt":"2026-06-10T09:48:27","slug":"cp-6-chlorination-of-2-methylpropan-2-ol","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-6-chlorination-of-2-methylpropan-2-ol\/","title":{"rendered":"CP 6 Chlorination of 2-methylpropan-2-ol"},"content":{"rendered":"<p><!-- OLS Edexcel International IAL Unit 3 Core Practical page. Full HTML content to be added. --><\/p>\n\n\n<section class=\"ols-cp-page ols-cp6-chlorination-page\">\n  <style>\n    .ols-cp-page {\n      --navy: #1C244B;\n      --blue: #2563eb;\n      --blue-2: #0f4fa8;\n      --soft-blue: #eef4ff;\n      --soft-green: #f0f7f1;\n      --soft-red: #fff7f7;\n      --soft-purple: #f7f0ff;\n      --soft-gold: #fff8e8;\n      --soft-cyan: #effaff;\n      --green: #3f8f46;\n      --red: #d94b2b;\n      --gold: #c9973a;\n      --purple: #7a3e9d;\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\n    .ols-cp-page * { box-sizing: border-box; }\n\n    .ols-cp-sidebar-shortcode {\n      max-width: 1180px;\n      margin: 0 auto;\n      padding: 24px 20px 0;\n    }\n\n    .ols-cp-shell {\n    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background: linear-gradient(135deg, #ffffff 0%, var(--soft-cyan) 100%); }\n\n    .ols-note-title {\n      display: flex;\n      align-items: center;\n      gap: 14px;\n      margin-bottom: 20px;\n    }\n\n    .ols-note-icon {\n      width: 52px;\n      height: 52px;\n      border-radius: 16px;\n      background: var(--navy);\n      color: #ffffff;\n      display: grid;\n      place-items: center;\n      font-size: 24px;\n      font-weight: 800;\n      flex-shrink: 0;\n    }\n\n    .ols-note-title h2,\n    .ols-related-card h2,\n    .ols-faq-card h2 {\n      margin: 0;\n      font-size: clamp(27px, 3.4vw, 42px);\n      line-height: 1.15;\n      font-weight: 850;\n      color: #111827;\n      letter-spacing: -0.03em;\n    }\n\n    .ols-note-card p,\n    .ols-note-card li,\n    .ols-related-card p,\n    .ols-faq-card p,\n    .ols-faq-card li {\n      font-size: clamp(15px, 1.25vw, 17px);\n      line-height: 1.7;\n      font-weight: 300;\n      color: var(--body-text);\n    }\n\n    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   bottom: 14px;\n      z-index: 3;\n      padding: 8px 12px;\n      border-radius: 999px;\n      background: rgba(28, 36, 75, 0.88);\n      color: #ffffff;\n      font-size: 12px;\n      line-height: 1;\n      font-weight: 800;\n      opacity: 0;\n      transform: translateY(6px);\n      transition: opacity 0.22s ease, transform 0.22s ease;\n      pointer-events: none;\n    }\n\n    .ols-figure-image:hover::after {\n      opacity: 1;\n      transform: translateY(0);\n    }\n\n    .ols-figure-image img {\n      width: 100%;\n      max-width: 100%;\n      height: auto;\n      display: block;\n      cursor: zoom-in;\n      transition: transform 0.32s ease, box-shadow 0.32s ease, filter 0.32s ease;\n      transform-origin: center center;\n      will-change: transform;\n      position: relative;\n      z-index: 2;\n    }\n\n    @media (hover: hover) and (pointer: fine) {\n      .ols-figure-card .ols-figure-image:hover img {\n        transform: scale(1.5);\n        box-shadow: 0 30px 80px 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background: #ffffff;\n      color: var(--navy);\n      font-family: Poppins, Arial, sans-serif;\n      font-size: 26px;\n      line-height: 1;\n      cursor: pointer;\n      font-weight: 800;\n      box-shadow: 0 14px 36px rgba(0, 0, 0, 0.24);\n    }\n\n    .ols-cp6-lightbox button:hover {\n      background: var(--soft-blue);\n    }\n\n    .ols-cp6-lightbox p {\n      position: absolute;\n      left: 28px;\n      right: 84px;\n      bottom: 16px;\n      margin: 0;\n      color: #ffffff;\n      font-size: 14px;\n      line-height: 1.4;\n    }\n\n    .ols-figure-image.contain {\n      padding: 18px;\n    }\n\n    .ols-figure-image.contain img {\n      width: auto;\n      max-width: 100%;\n    }\n\n    .ols-figure-image.formula-small {\n      min-height: 0;\n      padding: 22px;\n    }\n\n    .ols-figure-image.formula-small img {\n      width: auto;\n      max-width: 420px;\n      max-height: 210px;\n      margin: 0 auto;\n    }\n\n    .ols-figure-caption {\n      padding: 20px 24px 22px;\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n      border-top: 1px solid var(--border);\n    }\n\n    .ols-figure-caption h3 {\n      margin: 0 0 8px;\n      color: var(--navy);\n      font-size: clamp(20px, 2vw, 28px);\n      line-height: 1.25;\n      font-weight: 800;\n    }\n\n    .ols-figure-caption p {\n      margin: 0;\n      color: #5f6b85;\n      font-size: clamp(15px, 1.25vw, 17px);\n      line-height: 1.65;\n      font-weight: 300;\n    }\n\n    .ols-table-wrap {\n      overflow-x: auto;\n      border-radius: 22px;\n      border: 1px solid var(--border);\n      background: #ffffff;\n      margin-top: 18px;\n    }\n\n    .ols-table {\n      width: 100%;\n      border-collapse: collapse;\n      min-width: 680px;\n    }\n\n    .ols-table th {\n      background: var(--navy);\n      color: #ffffff;\n      padding: 15px 16px;\n      text-align: left;\n      font-size: 15px;\n      font-weight: 700;\n      vertical-align: top;\n    }\n\n    .ols-table td {\n  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minmax(0, 1.05fr) minmax(280px, 0.95fr);\n      gap: 18px;\n      align-items: start;\n    }\n\n    .ols-interactive-panel {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 22px;\n      padding: 20px;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-interactive-panel h3 {\n      margin: 0 0 12px;\n      font-size: 22px;\n      color: var(--navy);\n    }\n\n    .ols-action-stack {\n      display: grid;\n      gap: 10px;\n    }\n\n    .ols-action-btn {\n      width: 100%;\n      text-align: left;\n      background: #ffffff;\n      color: var(--navy);\n      border: 1px solid rgba(37, 99, 235, 0.22);\n      box-shadow: 0 8px 16px rgba(28, 36, 75, 0.06);\n    }\n\n    .ols-action-btn.is-active {\n      background: var(--navy);\n      color: #ffffff;\n      border-color: var(--navy);\n    }\n\n    .ols-action-btn.is-pulse { animation: olsCp6Pulse 1.7s infinite; }\n\n    @keyframes olsCp6Pulse {\n      0% { box-shadow: 0 8px 16px rgba(28, 36, 75, 0.06), 0 0 0 0 rgba(37, 99, 235, 0.30); }\n      70% { box-shadow: 0 8px 16px rgba(28, 36, 75, 0.06), 0 0 0 10px rgba(37, 99, 235, 0.00); }\n      100% { box-shadow: 0 8px 16px rgba(28, 36, 75, 0.06), 0 0 0 0 rgba(37, 99, 235, 0.00); }\n    }\n\n    .ols-product-tracker {\n      display: grid;\n      gap: 10px;\n      margin-top: 12px;\n    }\n\n    .ols-tracker-row {\n      display: grid;\n      grid-template-columns: 34px minmax(0, 1fr);\n      gap: 10px;\n      align-items: start;\n      padding: 12px;\n      border: 1px solid var(--border);\n      border-radius: 16px;\n      background: #f8fbff;\n      opacity: 0.45;\n      transition: opacity 0.2s ease, background 0.2s ease, transform 0.2s ease;\n    }\n\n    .ols-tracker-row.is-done {\n      opacity: 1;\n      background: #ffffff;\n    }\n\n    .ols-tracker-row.is-current {\n      opacity: 1;\n      background: var(--soft-green);\n      transform: translateY(-1px);\n      border-color: rgba(63, 143, 70, 0.25);\n    }\n\n  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{\n      display: inline-flex;\n      align-items: center;\n      gap: 8px;\n      padding: 10px 13px;\n      border-radius: 999px;\n      background: var(--soft-green);\n      color: var(--navy);\n      font-weight: 800;\n      border: 1px solid rgba(63, 143, 70, 0.25);\n      margin-top: 6px;\n    }\n\n    .ols-calc-grid {\n      display: grid;\n      grid-template-columns: repeat(3, minmax(0, 1fr));\n      gap: 14px;\n      margin-top: 20px;\n    }\n\n    .ols-related-grid {\n      display: grid;\n      grid-template-columns: repeat(3, minmax(0, 1fr));\n      gap: 16px;\n      margin-top: 18px;\n    }\n\n    .ols-related-item {\n      border: 1px solid var(--border);\n      border-radius: 18px;\n      padding: 18px;\n      background: #ffffff;\n      color: var(--navy);\n      text-decoration: none;\n      font-weight: 700;\n      line-height: 1.45;\n      transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;\n    }\n\n    .ols-related-item:hover {\n      transform: translateY(-2px);\n      box-shadow: 0 10px 22px rgba(28, 36, 75, 0.08);\n      background: var(--soft-blue);\n    }\n\n    .ols-faq-list {\n      display: grid;\n      gap: 14px;\n      margin-top: 18px;\n    }\n\n    .ols-faq-item {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 18px;\n      padding: 18px;\n    }\n\n    .ols-faq-item h3 {\n      margin: 0 0 8px;\n      font-size: 19px;\n      color: var(--navy);\n    }\n\n    .ols-faq-item p { margin: 0; }\n\n    @media (max-width: 1050px) {\n      .ols-process-grid,\n      .ols-related-grid,\n      .ols-mini-flow,\n      .ols-calc-grid {\n        grid-template-columns: repeat(2, minmax(0, 1fr));\n      }\n\n      .ols-interactive-grid { grid-template-columns: 1fr; }\n    }\n\n    @media (max-width: 760px) {\n      .ols-cp-shell { padding: 14px 12px 44px; }\n\n      .ols-title-card,\n      .ols-note-card,\n      .ols-related-card,\n      .ols-faq-card,\n      .ols-interactive-card {\n        padding: 24px 18px;\n        border-radius: 22px;\n      }\n\n      .ols-note-title,\n      .ols-interactive-head { align-items: flex-start; }\n      .ols-interactive-head { flex-direction: column; }\n      .ols-reset-btn { width: 100%; text-align: center; }\n\n      .ols-process-grid,\n      .ols-apparatus-grid,\n      .ols-error-grid,\n      .ols-qa-grid,\n      .ols-related-grid,\n      .ols-mini-flow,\n      .ols-calc-grid {\n        grid-template-columns: 1fr;\n      }\n\n      .ols-figure-image { min-height: 200px; }\n      .ols-figure-image.contain { padding: 10px; }\n      .ols-figure-image.formula-small img { max-width: 100%; max-height: none; }\n      .ols-cp6-lightbox { padding: 12px; }\n      .ols-cp6-lightbox p { display: none; }\n      .ols-table { min-width: 640px; }\n    }\n  <\/style>\n\n  <div class=\"ols-cp-sidebar-shortcode\"><aside class=\"ols-sidebar\">\r\n  <div class=\"ols-sidebar-header\">\r\n    <h3>Revision Notes<\/h3>\r\n    <p>Edexcel International A Level Chemistry<\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Core Practicals<\/h4>\r\n    <ul class=\"ols-topic-list\">\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/\">CP1: Molar Volume of a Gas<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-2-enthalpy-change-via-hess-law\/\">CP2: Hess's Law Enthalpy Change<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-3-concentration-of-hcl-by-titration\/\">CP3: Concentration of HCl<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-4-preparation-of-a-standard-solution\/\">CP4: Standard Solution Preparation<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-5-hydrolysis-of-halogenoalkanes\/\">CP5: Halogenoalkane Hydrolysis<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-6-chlorination-of-2-methylpropan-2-ol\/\">CP6: Chlorination of 2-methylpropan-2-ol<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-7-oxidation-of-propan-1-ol\/\">CP7: Oxidation of Propan-1-ol<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-8-analysis-of-inorganic-and-organic-unknowns\/\">CP8: Inorganic & Organic Unknowns<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-9a-9b-iodine-propanone-and-clock-reaction-kinetics\/\">CP9: Iodine-Propanone & Clock Reaction<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-10-activation-energy-of-a-reaction\/\">CP10: Activation Energy<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-11-ka-value-for-a-weak-acid\/\">CP11: Ka Value for Weak Acid<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-12-electrochemical-cells\/\">CP12: Electrochemical Cells<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-13a-13b-redox-titrations\/\">CP13: Redox Titrations<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-14-preparation-of-a-transition-metal-complex\/\">CP14: Transition Metal Complex Prep<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-15-analysis-of-inorganic-and-organic-unknowns\/\">CP15: Inorganic & Organic Unknowns<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-16-preparation-of-aspirin\/\">CP16: Preparation of Aspirin<\/a><\/li>\r\n    <\/ul>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Useful Links<\/h4>\r\n    <ul class=\"ols-topic-list\">\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\">Edexcel International Chemistry<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-6-energetics\/\">Energetics<\/a><\/li>\r\n      <li><a href=\"\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/\">Practical Skills<\/a><\/li>\r\n    <\/ul>\r\n  <\/div>\r\n<\/aside>\r\n\r\n<script>\r\ndocument.addEventListener('DOMContentLoaded', function () {\r\n  var currentPath = window.location.pathname.replace(\/\\\/$\/, '');\r\n  var sidebarLinks = document.querySelectorAll('.ols-sidebar .ols-topic-list a');\r\n\r\n  sidebarLinks.forEach(function (link) {\r\n    var linkPath = new URL(link.href, window.location.origin).pathname.replace(\/\\\/$\/, '');\r\n\r\n    if (linkPath === currentPath) {\r\n      link.closest('li').classList.add('active');\r\n    } else {\r\n      link.closest('li').classList.remove('active');\r\n    }\r\n  });\r\n});\r\n<\/script><\/div>\n\n  <div class=\"ols-cp-shell\">\n    <main class=\"ols-cp-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\/edexcel-international\/\">Edexcel International<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/\">Core Practicals<\/a> \/\n        <span>CP6: Chlorination of 2-methylpropan-2-ol<\/span>\n      <\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>CP6: Chlorination of 2-methylpropan-2-ol<\/h1>\n        <p class=\"ols-page-intro\">In this core practical, you prepare and purify <strong>2-chloro-2-methylpropane<\/strong> from <strong>2-methylpropan-2-ol<\/strong> and concentrated hydrochloric acid. The key skill is following the product through reaction, layer separation, washing, drying, distillation and chemical analysis.<\/p>\n        <div class=\"ols-badges\">\n          <div class=\"ols-badge\">Exam board: Edexcel International<\/div>\n          <div class=\"ols-badge\">Unit 3: Practical Skills in Chemistry I<\/div>\n          <div class=\"ols-badge\">Core Practical 6<\/div>\n          <div class=\"ols-badge\">Skill: Organic preparation, purification and analysis<\/div>\n        <\/div>\n        <div class=\"ols-author\">\n          <div class=\"ols-author-avatar\">MA<\/div>\n          <div>\n            <p><strong>Written by: Dr. Mohammed Al-Fatah<\/strong><\/p>\n            <p>Chemistry specialist revision notes for Edexcel International A Level Chemistry.<\/p>\n          <\/div>\n        <\/div>\n      <\/header>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">1<\/div>\n          <h2>What This Practical Is Testing<\/h2>\n        <\/div>\n        <p>This practical tests how an alcohol can be converted into a halogenoalkane. The hydroxyl group in <strong>2-methylpropan-2-ol<\/strong> is replaced by chlorine to form <strong>2-chloro-2-methylpropane<\/strong>.<\/p>\n        <span class=\"ols-equation\">(CH<sub>3<\/sub>)<sub>3<\/sub>COH + HCl \u2192 (CH<sub>3<\/sub>)<sub>3<\/sub>CCl + H<sub>2<\/sub>O<\/span>\n        <p>The reaction is only the first part. In exam questions, you also need to explain why the product is separated, washed, dried, distilled and then tested.<\/p>\n\n        <div class=\"ols-process-grid\" aria-label=\"CP6 practical process map\">\n          <div class=\"ols-process-step\">\n            <span>1<\/span>\n            <h3>Make crude product<\/h3>\n            <p>React 2-methylpropan-2-ol with concentrated hydrochloric acid in a fume cupboard.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>2<\/span>\n            <h3>Purify<\/h3>\n            <p>Use layer separation, sodium hydrogencarbonate washing and drying to remove impurities.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>3<\/span>\n            <h3>Analyse<\/h3>\n            <p>Distil the correct boiling fraction, then test the distillate for chloride ions.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Key idea:<\/strong> CP6 is not just a preparation practical. It is a purification practical. Track where the organic product is at every stage.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">2<\/div>\n          <h2>Safety and Apparatus<\/h2>\n        <\/div>\n        <p>This procedure must be carried out in a <strong>working fume cupboard<\/strong>. Concentrated hydrochloric acid produces fumes that are toxic and corrosive, and the organic product is flammable.<\/p>\n\n        <div class=\"ols-apparatus-grid\">\n          <div class=\"ols-apparatus-card\">\n            <h3>Main chemicals<\/h3>\n            <p>2-methylpropan-2-ol, concentrated hydrochloric acid, sodium hydrogencarbonate solution, anhydrous calcium chloride, anhydrous sodium sulfate, ethanol, sodium hydroxide, nitric acid and silver nitrate solution.<\/p>\n          <\/div>\n          <div class=\"ols-apparatus-card\">\n            <h3>Main equipment<\/h3>\n            <p>Conical flask with bung, separating funnel, measuring cylinders, filter funnel, distillation apparatus, pear-shaped or round-bottomed flask, thermometer, test tubes and sample tube.<\/p>\n          <\/div>\n          <div class=\"ols-apparatus-card\">\n            <h3>Personal protection<\/h3>\n            <p>Wear eye protection and gloves. Avoid skin contact with reactants and products.<\/p>\n          <\/div>\n          <div class=\"ols-apparatus-card\">\n            <h3>Vapour risk<\/h3>\n            <p>Avoid inhaling vapours. The concentrated acid fumes are especially hazardous for anyone with a respiratory problem.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-warning-box\">\n          <p><strong>Safety wording:<\/strong> Do not just write \u201cwear goggles\u201d. Link the fume cupboard to toxic and corrosive HCl fumes, and link no naked flames to flammable organic product.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card green\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">3<\/div>\n          <h2>Reaction Stage: Forming the Crude Chloroalkane<\/h2>\n        <\/div>\n        <p>The Pearson method uses <strong>10 cm<sup>3<\/sup><\/strong> of 2-methylpropan-2-ol and <strong>35 cm<sup>3<\/sup><\/strong> of concentrated hydrochloric acid. Some centre notes use a smaller-scale version, but the chemistry and purification logic are the same.<\/p>\n\n        <div class=\"ols-process-grid\" aria-label=\"CP6 reaction sequence\">\n          <div class=\"ols-process-step\">\n            <span>1<\/span>\n            <h3>Add reactants<\/h3>\n            <p>Pour the alcohol and concentrated hydrochloric acid into a large conical flask.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>2<\/span>\n            <h3>Swirl gently<\/h3>\n            <p>Very gently swirl the contents. The reaction mixture should remain controlled.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>3<\/span>\n            <h3>Bung and vent<\/h3>\n            <p>Fit the bung, swirl, then remove the bung to release pressure.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>4<\/span>\n            <h3>Repeat<\/h3>\n            <p>Continue swirling with intermittent pressure release for about 20 minutes.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>5<\/span>\n            <h3>Two layers form<\/h3>\n            <p>The upper layer is the crude organic product. The lower layer is aqueous.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>6<\/span>\n            <h3>Prepare to purify<\/h3>\n            <p>The crude product still contains impurities, so it must be separated, washed and dried.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Layer logic:<\/strong> The desired product is the <strong>upper organic layer<\/strong>. This is the layer you keep during separation.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">4<\/div>\n          <h2>The Reaction Equation and a Common Image Mix-up<\/h2>\n        <\/div>\n        <p>The CP6 reaction is the substitution of an alcohol group by chlorine. The product is <strong>2-chloro-2-methylpropane<\/strong>, not an alkene.<\/p>\n        <span class=\"ols-equation\">(CH<sub>3<\/sub>)<sub>3<\/sub>COH + HCl \u2192 (CH<sub>3<\/sub>)<sub>3<\/sub>CCl + H<sub>2<\/sub>O<\/span>\n\n        <div class=\"ols-figure-card\">\n          <div class=\"ols-figure-image contain formula-small\">\n            <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/Formula-Mechanism.webp\" alt=\"Dehydration of cyclohexanol to cyclohexene using concentrated phosphoric acid.\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <h3>Connected organic preparation: dehydration of cyclohexanol<\/h3>\n            <p>This small reaction image shows cyclohexanol forming cyclohexene using concentrated H<sub>3<\/sub>PO<sub>4<\/sub>. It is useful as a comparison, but it is <strong>not<\/strong> the CP6 chlorination reaction. In CP6, an alcohol is converted into a chloroalkane.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card gold\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">5<\/div>\n          <h2>Purification: What Each Step Removes<\/h2>\n        <\/div>\n        <p>The purification stage is the centre of this practical. The aim is to keep the organic product while removing acid, water and unreacted alcohol.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Stage<\/th>\n                <th>Action<\/th>\n                <th>What it removes or achieves<\/th>\n                <th>Exam point<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td><strong>Add anhydrous calcium chloride<\/strong><\/td>\n                <td>Swirl until dissolved.<\/td>\n                <td>Helps ensure unreacted alcohol is in the lower aqueous layer.<\/td>\n                <td>The crude organic product is still impure.<\/td>\n              <\/tr>\n              <tr>\n                <td><strong>Use separating funnel<\/strong><\/td>\n                <td>Allow two layers to settle.<\/td>\n                <td>Separates the upper organic layer from the lower aqueous layer.<\/td>\n                <td>Keep the upper organic layer.<\/td>\n              <\/tr>\n              <tr>\n                <td><strong>Wash with NaHCO<sub>3<\/sub><\/strong><\/td>\n                <td>Add sodium hydrogencarbonate solution and swirl.<\/td>\n                <td>Removes unreacted HCl by neutralisation.<\/td>\n                <td>CO<sub>2<\/sub> forms, so release pressure frequently.<\/td>\n              <\/tr>\n              <tr>\n                <td><strong>Repeat wash<\/strong><\/td>\n                <td>Wash again and run off lower layer.<\/td>\n                <td>Removes remaining acid and aqueous impurities.<\/td>\n                <td>Make sure no aqueous layer remains in the tap.<\/td>\n              <\/tr>\n              <tr>\n                <td><strong>Dry with Na<sub>2<\/sub>SO<sub>4<\/sub><\/strong><\/td>\n                <td>Add anhydrous sodium sulfate and leave until clear.<\/td>\n                <td>Removes water from the organic liquid.<\/td>\n                <td>The liquid should look completely clear before distillation.<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Neutralisation equation:<\/strong> HCl + NaHCO<sub>3<\/sub> \u2192 NaCl + CO<sub>2<\/sub> + H<sub>2<\/sub>O<\/p>\n        <\/div>\n      <\/article>\n\n      <section class=\"ols-interactive-card\" aria-label=\"Interactive CP6 purification walkthrough\">\n        <div class=\"ols-interactive-head\">\n          <div>\n            <h2>Interactive: Purify the Product<\/h2>\n            <p>Click through the stages to follow the organic product from crude reaction mixture to purified sample. Each step explains what is kept, what is removed and what observation matters.<\/p>\n          <\/div>\n          <button type=\"button\" class=\"ols-reset-btn\" id=\"olsCp6Reset\">Reset<\/button>\n        <\/div>\n\n        <div class=\"ols-interactive-grid\">\n          <div class=\"ols-interactive-panel\">\n            <h3>Product tracker<\/h3>\n            <div class=\"ols-product-tracker\" aria-label=\"Interactive product tracker\">\n              <div class=\"ols-tracker-row\" id=\"olsCp6Track1\"><div class=\"ols-tracker-dot\">1<\/div><div><strong>Reaction mixture<\/strong><span>Alcohol reacts with concentrated HCl. Crude organic product forms.<\/span><\/div><\/div>\n              <div class=\"ols-tracker-row\" id=\"olsCp6Track2\"><div class=\"ols-tracker-dot\">2<\/div><div><strong>Crude upper layer<\/strong><span>Upper layer contains product but still has impurities.<\/span><\/div><\/div>\n              <div class=\"ols-tracker-row\" id=\"olsCp6Track3\"><div class=\"ols-tracker-dot\">3<\/div><div><strong>Washed organic layer<\/strong><span>Sodium hydrogencarbonate removes unreacted acid.<\/span><\/div><\/div>\n              <div class=\"ols-tracker-row\" id=\"olsCp6Track4\"><div class=\"ols-tracker-dot\">4<\/div><div><strong>Dried organic liquid<\/strong><span>Anhydrous sodium sulfate removes water.<\/span><\/div><\/div>\n              <div class=\"ols-tracker-row\" id=\"olsCp6Track5\"><div class=\"ols-tracker-dot\">5<\/div><div><strong>Distilled product<\/strong><span>The 50-52 \u00b0C fraction is collected.<\/span><\/div><\/div>\n              <div class=\"ols-tracker-row\" id=\"olsCp6Track6\"><div class=\"ols-tracker-dot\">6<\/div><div><strong>Confirmed sample<\/strong><span>Silver nitrate test confirms chloride after hydrolysis.<\/span><\/div><\/div>\n            <\/div>\n          <\/div>\n\n          <div class=\"ols-interactive-panel\">\n            <h3>Choose each stage<\/h3>\n            <div class=\"ols-action-stack\">\n              <button type=\"button\" class=\"ols-action-btn is-pulse\" data-cp6-step=\"0\">1. React alcohol with concentrated HCl<\/button>\n              <button type=\"button\" class=\"ols-action-btn\" data-cp6-step=\"1\">2. Allow layers to separate<\/button>\n              <button type=\"button\" class=\"ols-action-btn\" data-cp6-step=\"2\">3. Wash with sodium hydrogencarbonate<\/button>\n              <button type=\"button\" class=\"ols-action-btn\" data-cp6-step=\"3\">4. Dry with anhydrous sodium sulfate<\/button>\n              <button type=\"button\" class=\"ols-action-btn\" data-cp6-step=\"4\">5. Distil the organic liquid<\/button>\n              <button type=\"button\" class=\"ols-action-btn\" data-cp6-step=\"5\">6. Test the distillate<\/button>\n            <\/div>\n            <div class=\"ols-working-box\" id=\"olsCp6Info\" style=\"margin-top: 16px;\">\n              <h4>Start here<\/h4>\n              <p>Begin by reacting 2-methylpropan-2-ol with concentrated hydrochloric acid. Your goal is to keep the organic product and remove anything that would contaminate it.<\/p>\n              <span class=\"ols-answer-pill\">Click step 1<\/span>\n            <\/div>\n          <\/div>\n        <\/div>\n\n        <script>\n          (function(){\n            var buttons = Array.prototype.slice.call(document.querySelectorAll('.ols-cp6-chlorination-page [data-cp6-step]'));\n            var reset = document.getElementById('olsCp6Reset');\n            var info = document.getElementById('olsCp6Info');\n            var tracks = [1,2,3,4,5,6].map(function(n){ return document.getElementById('olsCp6Track' + n); });\n            var copy = [\n              {\n                title: '1. Reaction stage',\n                body: '2-methylpropan-2-ol reacts with concentrated hydrochloric acid to form 2-chloro-2-methylpropane and water. Swirl gently and release pressure at intervals while the mixture reacts.',\n                pill: 'Product begins in the crude mixture'\n              },\n              {\n                title: '2. Layer separation',\n                body: 'After about 20 minutes, two layers are visible. The upper layer is the crude organic product, so the lower aqueous layer is run off and discarded.',\n                pill: 'Keep the upper organic layer'\n              },\n              {\n                title: '3. Sodium hydrogencarbonate wash',\n                body: 'Sodium hydrogencarbonate solution removes unreacted hydrochloric acid. Carbon dioxide is produced, so the separating funnel must be vented frequently.',\n                pill: 'Removes unreacted HCl'\n              },\n              {\n                title: '4. Drying stage',\n                body: 'Anhydrous sodium sulfate removes water from the organic layer. The mixture is left until the liquid looks completely clear, then the dry organic liquid is decanted.',\n                pill: 'Removes water'\n              },\n              {\n                title: '5. Distillation stage',\n                body: 'The dry organic liquid is distilled. Collect the fraction boiling between 50 \u00b0C and 52 \u00b0C because this matches the boiling point of 2-chloro-2-methylpropane.',\n                pill: 'Collect the 50-52 \u00b0C fraction'\n              },\n              {\n                title: '6. Analysis stage',\n                body: 'The distillate is warmed with ethanol and aqueous sodium hydroxide, then acidified with nitric acid before silver nitrate is added. A white precipitate of AgCl confirms chloride ions.',\n                pill: 'White AgCl precipitate'\n              }\n            ];\n            function setStep(index) {\n              buttons.forEach(function(btn, i){\n                btn.classList.toggle('is-active', i === index);\n                btn.classList.toggle('is-pulse', i === index + 1);\n              });\n              tracks.forEach(function(row, i){\n                row.classList.toggle('is-current', i === index);\n                row.classList.toggle('is-done', i < index);\n              });\n              info.innerHTML = '<h4>' + copy[index].title + '<\/h4><p>' + copy[index].body + '<\/p><span class=\"ols-answer-pill\">' + copy[index].pill + '<\/span>';\n            }\n            buttons.forEach(function(btn){\n              btn.addEventListener('click', function(){ setStep(parseInt(btn.getAttribute('data-cp6-step'), 10)); });\n            });\n            if (reset) {\n              reset.addEventListener('click', function(){\n                buttons.forEach(function(btn, i){ btn.classList.remove('is-active'); btn.classList.toggle('is-pulse', i === 0); });\n                tracks.forEach(function(row){ row.classList.remove('is-current'); row.classList.remove('is-done'); });\n                info.innerHTML = '<h4>Start here<\/h4><p>Begin by reacting 2-methylpropan-2-ol with concentrated hydrochloric acid. Your goal is to keep the organic product and remove anything that would contaminate it.<\/p><span class=\"ols-answer-pill\">Click step 1<\/span>';\n              });\n            }\n          })();\n        <\/script>\n      <\/section>\n\n      <article class=\"ols-note-card cyan\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">6<\/div>\n          <h2>Simple Distillation: Collecting the Pure Product<\/h2>\n        <\/div>\n        <p>After drying, the organic liquid is distilled. The pure product is collected as the fraction that boils between <strong>50 \u00b0C and 52 \u00b0C<\/strong>. This is close to the boiling temperature of 2-chloro-2-methylpropane, which is about <strong>51 \u00b0C<\/strong>.<\/p>\n\n        <div class=\"ols-mini-flow\">\n          <div class=\"ols-mini-pill\">\n            <small>Thermometer<\/small>\n            <strong>Measures vapour temperature<\/strong>\n            <span>The bulb should be near the outlet to the condenser, not deep inside the liquid.<\/span>\n          <\/div>\n          <div class=\"ols-mini-pill\">\n            <small>Condenser water<\/small>\n            <strong>In at bottom, out at top<\/strong>\n            <span>This fills the jacket and gives efficient counter-current cooling.<\/span>\n          <\/div>\n          <div class=\"ols-mini-pill\">\n            <small>Heating<\/small>\n            <strong>Use safe heating<\/strong>\n            <span>Organic liquids can be flammable, so avoid naked flames.<\/span>\n          <\/div>\n          <div class=\"ols-mini-pill\">\n            <small>Fraction<\/small>\n            <strong>50-52 \u00b0C<\/strong>\n            <span>Collecting the correct boiling range improves product purity.<\/span>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n          <div class=\"ols-figure-image\">\n            <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/Simple-distillation-process-overview.webp\" alt=\"Simple distillation process overview showing correct thermometer position, water flow, heating and collection flask.\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <h3>Simple distillation process<\/h3>\n            <p>This visual focuses on the practical technique: thermometer position, condenser water flow, safe heating and collection of the distillate.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n          <div class=\"ols-figure-image\">\n            <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/Simple-distillation-apparatus-overview.webp\" alt=\"Simple distillation apparatus labelled with thermometer, distillation flask, Liebig condenser, water in, water out and receiver.\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <h3>Simple distillation apparatus<\/h3>\n            <p>The condenser cools the vapour so it condenses into the receiver. Water enters at the lower connection and leaves at the upper connection.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">7<\/div>\n          <h2>Reflux vs Distillation<\/h2>\n        <\/div>\n        <p>Reflux and distillation both use a condenser, but they have different purposes. In reflux, condensed vapour returns to the reaction flask. In distillation, vapour is condensed and collected in a separate receiver.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Technique<\/th>\n                <th>Purpose<\/th>\n                <th>What happens to the condensed liquid?<\/th>\n                <th>Why it matters for CP6<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td><strong>Reflux<\/strong><\/td>\n                <td>Heat a reaction mixture for a long time without losing volatile reactants or solvent.<\/td>\n                <td>It drips back into the flask.<\/td>\n                <td>Useful for carrying out reactions, but not for collecting a purified product.<\/td>\n              <\/tr>\n              <tr>\n                <td><strong>Simple distillation<\/strong><\/td>\n                <td>Separate and collect a liquid product based on boiling point.<\/td>\n                <td>It is collected in a receiver.<\/td>\n                <td>Used in CP6 to collect the 50-52 \u00b0C fraction of 2-chloro-2-methylpropane.<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n          <div class=\"ols-figure-image\">\n            <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/Reflux-setup-chemistry-apparatus-explained.webp\" alt=\"Reflux setup labelled with condenser, water in, water out, round-bottom flask and heating mantle.\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <h3>Reflux setup comparison<\/h3>\n            <p>In reflux, the condenser is vertical and condensed liquid returns to the flask. In CP6 purification, the apparatus is rearranged for simple distillation so the product can be collected.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card green\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">8<\/div>\n          <h2>Analysis: Testing the Distillate for Chloride<\/h2>\n        <\/div>\n        <p>The final sample is tested to show that it contains a chloroalkane. The chloroalkane must first be hydrolysed so chloride ions are released, then silver nitrate can be used to form a silver chloride precipitate.<\/p>\n\n        <div class=\"ols-process-grid\" aria-label=\"CP6 analysis sequence\">\n          <div class=\"ols-process-step\">\n            <span>1<\/span>\n            <h3>Add distillate<\/h3>\n            <p>Place a few drops of the distilled product into a test tube.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>2<\/span>\n            <h3>Add ethanol and NaOH<\/h3>\n            <p>Add ethanol and aqueous sodium hydroxide, then warm in a water bath.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>3<\/span>\n            <h3>Hydrolyse<\/h3>\n            <p>Hydroxide ions hydrolyse the chloroalkane, releasing chloride ions.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>4<\/span>\n            <h3>Acidify<\/h3>\n            <p>Add excess nitric acid before silver nitrate to remove excess hydroxide ions.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>5<\/span>\n            <h3>Add AgNO<sub>3<\/sub><\/h3>\n            <p>Silver ions react with chloride ions.<\/p>\n          <\/div>\n          <div class=\"ols-process-step\">\n            <span>6<\/span>\n            <h3>Observation<\/h3>\n            <p>A white precipitate of silver chloride forms.<\/p>\n          <\/div>\n        <\/div>\n\n        <span class=\"ols-equation\">Ag<sup>+<\/sup>(aq) + Cl<sup>&#8211;<\/sup>(aq) \u2192 AgCl(s)<\/span>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Expected result:<\/strong> A white precipitate confirms chloride ions after hydrolysis of the chloroalkane.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">9<\/div>\n          <h2>Boiling Point, Solubility and Purity<\/h2>\n        <\/div>\n        <p>The product and reactant have different physical properties because the alcohol can form hydrogen bonds, while the chloroalkane cannot form hydrogen bonds with water.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Substance<\/th>\n                <th>Boiling temperature<\/th>\n                <th>Solubility in water<\/th>\n                <th>Explanation<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td><strong>2-methylpropan-2-ol<\/strong><\/td>\n                <td>82 \u00b0C<\/td>\n                <td>Soluble<\/td>\n                <td>Can form hydrogen bonds between its own molecules and with water.<\/td>\n              <\/tr>\n              <tr>\n                <td><strong>2-chloro-2-methylpropane<\/strong><\/td>\n                <td>51 \u00b0C<\/td>\n                <td>Insoluble<\/td>\n                <td>Cannot form hydrogen bonds with water. Intermolecular forces are weaker overall.<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Purity check:<\/strong> A pure liquid has a boiling temperature close to the data-book value. Impurities can change the observed boiling range.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card gold\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">10<\/div>\n          <h2>Exam-Style Yield Calculation Walkthrough<\/h2>\n        <\/div>\n        <p>The exam-style question uses a related preparation of <strong>2-bromopropane<\/strong> from propan-2-ol. The method for percentage yield is the same: use density to find mass, convert to moles, find theoretical product mass, then compare with actual mass.<\/p>\n\n        <div class=\"ols-calc-grid\">\n          <div class=\"ols-calc-step\">\n            <span>1<\/span>\n            <h3>Mass of alcohol<\/h3>\n            <p>mass propan-2-ol = 3.0 \u00d7 0.79 = <strong>2.37 g<\/strong><\/p>\n          <\/div>\n          <div class=\"ols-calc-step\">\n            <span>2<\/span>\n            <h3>Moles of alcohol<\/h3>\n            <p>moles = 2.37 \u00f7 60.1 = <strong>0.0394 mol<\/strong><\/p>\n          <\/div>\n          <div class=\"ols-calc-step\">\n            <span>3<\/span>\n            <h3>Theoretical moles<\/h3>\n            <p>The reaction is 1:1, so theoretical moles of 2-bromopropane = <strong>0.0394 mol<\/strong><\/p>\n          <\/div>\n          <div class=\"ols-calc-step\">\n            <span>4<\/span>\n            <h3>Theoretical mass<\/h3>\n            <p>0.0394 \u00d7 123 = <strong>4.85 g<\/strong><\/p>\n          <\/div>\n          <div class=\"ols-calc-step\">\n            <span>5<\/span>\n            <h3>Actual mass<\/h3>\n            <p>actual mass = 1.4 \u00d7 1.31 = <strong>1.83 g<\/strong><\/p>\n          <\/div>\n          <div class=\"ols-calc-step\">\n            <span>6<\/span>\n            <h3>Percentage yield<\/h3>\n            <p>% yield = 1.83 \u00f7 4.85 \u00d7 100 = <strong>38%<\/strong><\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Why less than 100%?<\/strong> Product can be lost during purification, the reaction may be incomplete, or competing reactions may occur.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">11<\/div>\n          <h2>Questions and Answers<\/h2>\n        <\/div>\n        <p>These are the key CP6 questions from the practical sheets, written in revision-note format.<\/p>\n\n        <div class=\"ols-qa-grid\">\n          <div class=\"ols-qa-card\">\n            <h3>1. Write the equation for CP6.<\/h3>\n            <p><strong>(CH<sub>3<\/sub>)<sub>3<\/sub>COH + HCl \u2192 (CH<sub>3<\/sub>)<sub>3<\/sub>CCl + H<sub>2<\/sub>O<\/strong><\/p>\n          <\/div>\n          <div class=\"ols-qa-card\">\n            <h3>2. What does sodium hydrogencarbonate remove?<\/h3>\n            <p>It removes unreacted hydrochloric acid by neutralisation.<\/p>\n            <p><strong>HCl + NaHCO<sub>3<\/sub> \u2192 NaCl + CO<sub>2<\/sub> + H<sub>2<\/sub>O<\/strong><\/p>\n          <\/div>\n          <div class=\"ols-qa-card\">\n            <h3>3. Why is pressure released during washing?<\/h3>\n            <p>Carbon dioxide gas is produced when sodium hydrogencarbonate reacts with acid. The bung must be removed at intervals to release pressure safely.<\/p>\n          <\/div>\n          <div class=\"ols-qa-card\">\n            <h3>4. Why does the alcohol dissolve in water?<\/h3>\n            <p>2-methylpropan-2-ol can form hydrogen bonds with water, so it is soluble.<\/p>\n          <\/div>\n          <div class=\"ols-qa-card\">\n            <h3>5. Why is 2-chloro-2-methylpropane insoluble in water?<\/h3>\n            <p>It cannot form hydrogen bonds with water. It has weaker intermolecular attractions than the alcohol.<\/p>\n          <\/div>\n          <div class=\"ols-qa-card\">\n            <h3>6. Why is the alcohol boiling temperature higher?<\/h3>\n            <p>Intermolecular hydrogen bonds in the alcohol are stronger than the dipole-dipole attractions and London forces between 2-chloro-2-methylpropane molecules.<\/p>\n          <\/div>\n          <div class=\"ols-qa-card\">\n            <h3>7. Why does a brown vapour form in the bromide extension?<\/h3>\n            <p>Bromide ions are oxidised to bromine, Br<sub>2<\/sub>, by concentrated sulfuric acid. Bromine is brown.<\/p>\n          <\/div>\n          <div class=\"ols-qa-card\">\n            <h3>8. Equations for brown vapour formation<\/h3>\n            <p><strong>KBr + H<sub>2<\/sub>SO<sub>4<\/sub> \u2192 KHSO<sub>4<\/sub> + HBr<\/strong><\/p>\n            <p><strong>2HBr + H<sub>2<\/sub>SO<sub>4<\/sub> \u2192 SO<sub>2<\/sub> + Br<sub>2<\/sub> + 2H<sub>2<\/sub>O<\/strong><\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">12<\/div>\n          <h2>Common Mistakes in CP6<\/h2>\n        <\/div>\n        <div class=\"ols-error-grid\">\n          <div class=\"ols-error-card\">\n            <h3>Mistake 1: Keeping the wrong layer<\/h3>\n            <p>The crude product is the upper organic layer. The lower aqueous layer is run off and discarded.<\/p>\n          <\/div>\n          <div class=\"ols-error-card\">\n            <h3>Mistake 2: Forgetting to vent<\/h3>\n            <p>Sodium hydrogencarbonate produces CO<sub>2<\/sub>. Pressure builds up in the separating funnel if it is not vented.<\/p>\n          <\/div>\n          <div class=\"ols-error-card\">\n            <h3>Mistake 3: Adding AgNO<sub>3<\/sub> too early<\/h3>\n            <p>The chloroalkane must be hydrolysed first so chloride ions are released.<\/p>\n          <\/div>\n          <div class=\"ols-error-card\">\n            <h3>Mistake 4: Missing the acidification step<\/h3>\n            <p>Nitric acid is added before silver nitrate to remove excess hydroxide ions that could interfere.<\/p>\n          <\/div>\n          <div class=\"ols-error-card\">\n            <h3>Mistake 5: Using reflux wording for distillation<\/h3>\n            <p>Distillation collects the condensed liquid. Reflux returns condensed liquid to the flask.<\/p>\n          <\/div>\n          <div class=\"ols-error-card\">\n            <h3>Mistake 6: Using the wrong boiling range<\/h3>\n            <p>For the Pearson CP6 procedure, collect the 50-52 \u00b0C fraction.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n      <section class=\"ols-faq-card\">\n        <h2>CP6 FAQs<\/h2>\n        <div class=\"ols-faq-list\">\n          <div class=\"ols-faq-item\">\n            <h3>What is the aim of CP6?<\/h3>\n            <p>To produce and purify a sample of 2-chloro-2-methylpropane from 2-methylpropan-2-ol and concentrated hydrochloric acid.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>Why is sodium hydrogencarbonate used?<\/h3>\n            <p>It neutralises unreacted hydrochloric acid. Carbon dioxide gas is produced, so pressure must be released frequently.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>Why is anhydrous sodium sulfate used?<\/h3>\n            <p>It is a drying agent. It removes water from the organic product before distillation.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>Why is the 50-52 \u00b0C fraction collected?<\/h3>\n            <p>This boiling range matches the boiling temperature of 2-chloro-2-methylpropane, so collecting this fraction improves purity.<\/p>\n          <\/div>\n          <div class=\"ols-faq-item\">\n            <h3>What does the silver nitrate test show?<\/h3>\n            <p>After hydrolysis and acidification, a white precipitate of AgCl shows that chloride ions are present.<\/p>\n          <\/div>\n        <\/div>\n      <\/section>\n    <\/main>\n  <\/div>\n\n  <div class=\"ols-cp6-lightbox\" id=\"olsCp6Lightbox\" aria-hidden=\"true\">\n    <button type=\"button\" aria-label=\"Close image\">&times;<\/button>\n    <img decoding=\"async\" src=\"\" alt=\"\">\n    <p><\/p>\n  <\/div>\n\n  <script>\n    (function(){\n      function initCp6Lightbox(){\n        var page = document.querySelector('.ols-cp6-chlorination-page');\n        if (!page) { return; }\n\n        var lb = page.querySelector('#olsCp6Lightbox');\n        if (!lb || lb.dataset.olsReady === '1') { return; }\n        lb.dataset.olsReady = '1';\n\n        var lbImg = lb.querySelector('img');\n        var lbText = lb.querySelector('p');\n        var closeBtn = lb.querySelector('button');\n\n        function openLightbox(img){\n          if (!img) { return; }\n          lbImg.src = img.currentSrc || img.src;\n          lbImg.alt = img.alt || '';\n          lbText.textContent = img.alt || 'Image preview';\n          lb.classList.add('is-open');\n          lb.setAttribute('aria-hidden', 'false');\n          document.documentElement.style.overflow = 'hidden';\n        }\n\n        function closeLightbox(){\n          lb.classList.remove('is-open');\n          lb.setAttribute('aria-hidden', 'true');\n          lbImg.src = '';\n          lbImg.alt = '';\n          lbText.textContent = '';\n          document.documentElement.style.overflow = '';\n        }\n\n        page.addEventListener('click', function(e){\n          var frame = e.target.closest('.ols-figure-image');\n          if (!frame || !page.contains(frame)) { return; }\n          var img = frame.querySelector('img');\n          openLightbox(img);\n        });\n\n        if (closeBtn) { closeBtn.addEventListener('click', closeLightbox); }\n\n        lb.addEventListener('click', function(e){\n          if (e.target === lb) { closeLightbox(); }\n        });\n\n        document.addEventListener('keydown', function(e){\n          if (e.key === 'Escape' && lb.classList.contains('is-open')) { closeLightbox(); }\n        });\n      }\n\n      if (document.readyState === 'loading') {\n        document.addEventListener('DOMContentLoaded', initCp6Lightbox);\n      } else {\n        initCp6Lightbox();\n      }\n    })();\n  <\/script>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Revision Notes \/ A Level Chemistry \/ Edexcel International \/ Core Practicals \/ CP6: Chlorination of 2-methylpropan-2-ol CP6: Chlorination of 2-methylpropan-2-ol In this core practical, you prepare and purify 2-chloro-2-methylpropane from 2-methylpropan-2-ol and concentrated hydrochloric acid. The key skill is following the product through reaction, layer separation, washing, drying, distillation and chemical analysis. Exam board: [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":5028,"menu_order":5,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-4961","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4961","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=4961"}],"version-history":[{"count":0,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4961\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/5028"}],"wp:attachment":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/media?parent=4961"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}