{"id":4827,"date":"2026-06-03T06:24:32","date_gmt":"2026-06-03T05:24:32","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/combustion\/"},"modified":"2026-10-25T12:09:05","modified_gmt":"2026-10-25T12:09:05","slug":"combustion","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/combustion\/","title":{"rendered":"Combustion"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-combustion-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      --green: #3f8f46;\n      --red: #d94b2b;\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\n    .ols-revision-page * { box-sizing: border-box; }\n\n    .ols-main {\n      min-width: 0;\n      max-width: 970px;\n    }\n\n    .ols-breadcrumbs {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 8px;\n      margin: 10px 0 22px;\n      font-size: 15px;\n      color: var(--grey-text);\n    }\n\n    .ols-breadcrumbs a,\n    .ols-breadcrumbs span {\n      color: var(--grey-text);\n      text-decoration: none;\n      font-weight: 600;\n    }\n\n    .ols-breadcrumbs a:hover {\n      color: var(--blue);\n      text-decoration: underline;\n      text-underline-offset: 3px;\n    }\n\n    .ols-title-card,\n    .ols-note-card,\n    .ols-h5p-card,\n    .ols-faq-card,\n    .ols-related-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\n    .ols-title-card {\n      background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n    }\n\n    .ols-title-card h1 {\n      margin: 0 0 18px;\n      font-size: clamp(36px, 5vw, 58px);\n      line-height: 1.08;\n      font-weight: 800;\n      letter-spacing: -0.04em;\n      color: #111827;\n    }\n\n    .ols-page-intro {\n      font-size: 19px;\n      line-height: 1.7;\n      font-weight: 300;\n      color: var(--body-text);\n      margin: 0 0 22px;\n    }\n\n    .ols-badges {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 12px;\n      margin-bottom: 22px;\n    }\n\n    .ols-badge {\n      display: inline-flex;\n      align-items: center;\n      padding: 9px 14px;\n      border-radius: 999px;\n      background: #ffffff;\n      border: 1px solid var(--border);\n      font-size: 15px;\n      font-weight: 600;\n      color: var(--navy);\n    }\n\n    .ols-note-card.soft {\n      background: linear-gradient(135deg, #ffffff 0%, var(--soft-red) 100%);\n    }\n\n    .ols-note-card.purple {\n      background: linear-gradient(135deg, #ffffff 0%, var(--soft-purple) 100%);\n    }\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-h5p-card h2,\n    .ols-faq-card h2,\n    .ols-related-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\n    .ols-h5p-card h2,\n    .ols-faq-card h2,\n    .ols-related-card h2 {\n      margin-bottom: 14px;\n    }\n\n    .ols-note-card p,\n    .ols-note-card li {\n      font-size: clamp(15px, 1.25vw, 17px);\n      line-height: 1.65;\n      font-weight: 300;\n      color: var(--body-text);\n    }\n\n    .ols-h5p-card p,\n    .ols-faq-card p,\n    .ols-related-card p {\n      font-size: clamp(15px, 1.3vw, 18px);\n      line-height: 1.65;\n      font-weight: 300;\n      color: var(--body-text);\n    }\n\n    .ols-note-card strong,\n    .ols-h5p-card strong,\n    .ols-faq-card strong,\n    .ols-related-card strong {\n      font-weight: 700;\n      color: var(--navy);\n    }\n\n    .ols-note-card ul,\n    .ols-note-card ol {\n      margin: 0;\n      padding-left: 22px;\n    }\n\n    .ols-key-box {\n      margin-top: 20px;\n      background: var(--soft-green);\n      border: 1px solid rgba(63, 143, 70, 0.25);\n      border-radius: 20px;\n      padding: 18px 20px;\n    }\n\n    .ols-key-box p {\n      margin: 0;\n      font-weight: 400;\n      color: var(--navy);\n    }\n\n    .ols-definition-box {\n      background: linear-gradient(135deg, #ffffff, var(--soft-purple));\n      border: 2px dashed rgba(122, 62, 157, 0.35);\n      border-radius: 24px;\n      padding: 24px;\n      margin-top: 22px;\n    }\n\n    .ols-definition-box p {\n      margin: 0;\n      color: var(--body-text);\n    }\n\n    .ols-reaction-summary {\n      display: grid;\n      grid-template-columns: repeat(2, minmax(0, 1fr));\n      gap: 14px;\n      margin-top: 20px;\n    }\n\n    .ols-summary-item {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 18px;\n      padding: 16px;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-summary-item span {\n      display: block;\n      font-size: 13px;\n      font-weight: 700;\n      color: var(--grey-text);\n      margin-bottom: 6px;\n    }\n\n    .ols-summary-item strong {\n      display: block;\n      font-size: 16px;\n      line-height: 1.45;\n      color: var(--navy);\n    }\n\n    .ols-figure-card {\n      margin: 26px 0 4px;\n      border: 1px solid var(--border);\n      border-radius: 26px;\n      overflow: hidden;\n      background: #ffffff;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-figure-image {\n      width: 100%;\n      min-height: 260px;\n      display: flex;\n      align-items: center;\n      justify-content: center;\n      background: #ffffff;\n      padding: 20px;\n    }\n\n    .ols-figure-image img {\n      max-width: 100%;\n      height: auto;\n      display: block;\n      border-radius: 18px;\n    }\n\n    .ols-figure-caption {\n      padding: 18px 22px 20px;\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n    }\n\n    .ols-figure-caption p {\n      margin: 0;\n      color: #5f6b85;\n      font-size: clamp(15px, 1.25vw, 17px);\n      line-height: 1.6;\n      font-weight: 300;\n      font-style: italic;\n    }\n\n    .ols-table-wrap {\n      overflow: hidden;\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      table-layout: fixed;\n    }\n\n    .ols-table th {\n      background: var(--navy);\n      color: #ffffff;\n      padding: 16px;\n      text-align: left;\n      font-size: clamp(14px, 1.2vw, 17px);\n      font-weight: 600;\n      overflow-wrap: anywhere;\n    }\n\n    .ols-table td {\n      padding: 16px;\n      border-bottom: 1px solid var(--border);\n      font-size: clamp(14px, 1.15vw, 16px);\n      line-height: 1.45;\n      color: var(--body-text);\n      vertical-align: top;\n      overflow-wrap: anywhere;\n    }\n\n    .ols-table tr:last-child td {\n      border-bottom: none;\n    }\n\n    .ols-h5p-card {\n      background: linear-gradient(135deg, #ffffff 0%, #f7f0ff 100%);\n    }\n\n    .ols-h5p-frame {\n      margin-top: 22px;\n      padding: 18px;\n      border-radius: 24px;\n      background: #ffffff;\n      border: 1px solid var(--border);\n      box-shadow: inset 0 0 0 1px rgba(28, 36, 75, 0.03);\n    }\n\n    .ols-infographic-full {\n      width: 100%;\n      max-width: 100%;\n      margin: 6px 0 30px;\n      overflow: hidden;\n    }\n\n    .ols-infographic-title {\n      margin: 0 0 18px;\n    }\n\n    .ols-infographic-full-frame {\n      width: 100%;\n      max-width: 100%;\n      border-radius: 22px;\n      overflow: hidden;\n      box-shadow: 0 18px 42px rgba(28, 36, 75, 0.13);\n      background: #ffffff;\n      border: 1px solid var(--border);\n      padding: 24px;\n    }\n\n    .ols-infographic-grid {\n      display: grid;\n      grid-template-columns: repeat(2, minmax(0, 1fr));\n      gap: 16px;\n    }\n\n    .ols-info-panel {\n      border: 1px solid var(--border);\n      border-radius: 20px;\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n      padding: 18px;\n    }\n\n    .ols-info-panel h3 {\n      margin: 0 0 8px;\n      font-size: 21px;\n      line-height: 1.25;\n      color: var(--navy);\n    }\n\n    .ols-info-panel p {\n      margin: 0;\n      font-size: 16px;\n      line-height: 1.6;\n      color: var(--body-text);\n      font-weight: 300;\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 20px;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-faq-item h3 {\n      margin: 0 0 8px;\n      font-size: 20px;\n      line-height: 1.35;\n      color: var(--navy);\n    }\n\n    .ols-faq-item p {\n      margin: 0;\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: 600;\n      line-height: 1.5;\n      transition: transform 0.2s ease, box-shadow 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    }\n\n    .ols-course-cta-topic4,\n    .ols-course-cta-topic4 * {\n      box-sizing: border-box;\n    }\n\n    .ols-course-cta-topic4 {\n      width: 100%;\n      margin: 30px 0 24px;\n      font-family: Poppins, Arial, sans-serif;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-card {\n      overflow: hidden;\n      border-radius: 30px;\n      border: 1px solid var(--border);\n      background:\n        radial-gradient(circle at top left, rgba(37, 99, 235, 0.16), transparent 34%),\n        linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n      box-shadow: var(--shadow);\n      padding: 30px;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-top {\n      display: grid;\n      grid-template-columns: minmax(260px, 0.9fr) minmax(0, 1.1fr);\n      gap: 28px;\n      align-items: center;\n      margin-bottom: 24px;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-image-link {\n      display: block;\n      text-decoration: none;\n      border-radius: 24px;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-image {\n      width: 100%;\n      border-radius: 24px;\n      overflow: hidden;\n      border: 1px solid var(--border);\n      background: #ffffff;\n      box-shadow: var(--inner-shadow);\n      transition: transform 0.35s ease, box-shadow 0.35s ease;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-image img {\n      width: 100%;\n      height: auto;\n      display: block;\n      transition: transform 0.45s ease;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-image-link:hover .ols-course-cta-image {\n      transform: translateY(-8px) scale(1.015);\n      box-shadow:\n        0 26px 60px rgba(28, 36, 75, 0.18),\n        0 0 0 1px rgba(37, 99, 235, 0.12);\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-image-link:hover .ols-course-cta-image img {\n      transform: scale(1.03);\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-header-row {\n      display: flex;\n      flex-wrap: wrap;\n      align-items: center;\n      justify-content: space-between;\n      gap: 14px;\n      margin-bottom: 18px;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-kicker {\n      display: inline-flex;\n      align-items: center;\n      padding: 8px 14px;\n      border-radius: 999px;\n      background: #ffffff;\n      border: 1px solid rgba(37, 99, 235, 0.18);\n      color: var(--blue);\n      font-size: 14px;\n      line-height: 1.2;\n      font-weight: 700;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-course-cta-topic4 h2 {\n      margin: 0 0 14px;\n      font-size: clamp(28px, 3.5vw, 42px);\n      line-height: 1.15;\n      font-weight: 800;\n      letter-spacing: -0.03em;\n      color: #111827;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-intro-stats {\n      display: grid;\n      grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);\n      gap: 24px;\n      align-items: stretch;\n      margin: 0 0 30px;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-intro {\n      margin: 0;\n      color: var(--body-text);\n      font-size: clamp(16px, 1.4vw, 18px);\n      line-height: 1.7;\n      font-weight: 300;\n      align-self: center;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-stats {\n      display: grid;\n      grid-template-columns: repeat(2, minmax(0, 1fr));\n      gap: 14px;\n      margin: 0;\n    }\n\n    .ols-course-cta-topic4 .ols-course-stat {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 18px;\n      padding: 16px;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-course-cta-topic4 .ols-course-stat span {\n      display: block;\n      margin-bottom: 6px;\n      color: var(--grey-text);\n      font-size: 13px;\n      line-height: 1.35;\n      font-weight: 700;\n    }\n\n    .ols-course-cta-topic4 .ols-course-stat strong {\n      display: block;\n      color: var(--navy);\n      font-size: 18px;\n      line-height: 1.35;\n      font-weight: 800;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-features {\n      display: grid;\n      grid-template-columns: repeat(2, minmax(0, 1fr));\n      gap: 14px;\n      margin: 0 0 30px;\n    }\n\n    .ols-course-cta-topic4 .ols-course-feature {\n      background: rgba(255, 255, 255, 0.78);\n      border: 1px solid var(--border);\n      border-radius: 18px;\n      padding: 16px 18px;\n    }\n\n    .ols-course-cta-topic4 .ols-course-feature h3 {\n      margin: 0 0 6px;\n      color: var(--navy);\n      font-size: 18px;\n      line-height: 1.3;\n      font-weight: 800;\n    }\n\n    .ols-course-cta-topic4 .ols-course-feature p {\n      margin: 0;\n      color: var(--body-text);\n      font-size: 15px;\n      line-height: 1.6;\n      font-weight: 300;\n    }\n\n    .ols-course-cta-topic4 .ols-course-cta-bottom {\n      display: flex;\n      justify-content: center;\n      padding-top: 22px;\n      border-top: 1px solid var(--border);\n    }\n\n    .ols-course-cta-topic4 .ols-course-button {\n      display: inline-flex;\n      align-items: center;\n      justify-content: center;\n      padding: 15px 28px;\n      border-radius: 999px;\n      background: var(--navy);\n      color: #ffffff;\n      text-decoration: none;\n      font-size: 16px;\n      line-height: 1.2;\n      font-weight: 800;\n      box-shadow: 0 12px 26px rgba(28, 36, 75, 0.18);\n      transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;\n    }\n\n    .ols-course-cta-topic4 .ols-course-button:hover {\n      transform: translateY(-2px);\n      background: var(--blue);\n      color: #ffffff;\n      box-shadow: 0 16px 32px rgba(37, 99, 235, 0.24);\n    }\n\n    .ols-course-cta-topic4 .ols-course-button-top {\n      flex-shrink: 0;\n      padding: 12px 22px;\n      font-size: 15px;\n    }\n\n    @media (max-width: 1050px) {\n\n      .ols-main {\n        max-width: none;\n      }\n\n      .ols-related-grid,\n      .ols-infographic-grid {\n        grid-template-columns: repeat(2, minmax(0, 1fr));\n      }\n\n      .ols-course-cta-topic4 .ols-course-cta-top,\n      .ols-course-cta-topic4 .ols-course-cta-intro-stats {\n        grid-template-columns: 1fr;\n      }\n\n      .ols-course-cta-topic4 .ols-course-cta-image-link {\n        max-width: 520px;\n        margin: 0 auto;\n      }\n    }\n\n    @media (max-width: 760px) {\n\n      .ols-title-card,\n      .ols-note-card,\n      .ols-h5p-card,\n      .ols-faq-card,\n      .ols-related-card {\n        padding: 24px 18px;\n        border-radius: 22px;\n      }\n\n      .ols-note-title {\n        align-items: flex-start;\n      }\n\n      .ols-figure-card {\n        border-radius: 22px;\n      }\n\n      .ols-figure-image {\n        min-height: 210px;\n        padding: 14px;\n      }\n\n      .ols-figure-caption {\n        padding: 18px;\n      }\n\n      .ols-infographic-full {\n        margin: 0 0 26px;\n      }\n\n      .ols-infographic-full-frame {\n        border-radius: 18px;\n        padding: 18px;\n      }\n\n      .ols-table thead {\n        display: none;\n      }\n\n      .ols-table,\n      .ols-table tbody,\n      .ols-table tr,\n      .ols-table td {\n        display: block;\n        width: 100%;\n      }\n\n      .ols-table tr {\n        border-bottom: 1px solid var(--border);\n        padding: 12px 0;\n      }\n\n      .ols-table tr:last-child {\n        border-bottom: none;\n      }\n\n      .ols-table td {\n        border-bottom: none;\n        padding: 10px 14px;\n      }\n\n      .ols-table td::before {\n        content: attr(data-label);\n        display: block;\n        margin-bottom: 5px;\n        color: var(--navy);\n        font-weight: 800;\n      }\n\n      .ols-course-cta-topic4 {\n        margin: 26px 0 22px;\n      }\n\n      .ols-course-cta-topic4 .ols-course-cta-card {\n        padding: 20px;\n        border-radius: 24px;\n      }\n\n      .ols-course-cta-topic4 .ols-course-cta-header-row {\n        align-items: stretch;\n      }\n\n      .ols-course-cta-topic4 .ols-course-button-top {\n        width: 100%;\n      }\n\n      .ols-course-cta-topic4 .ols-course-cta-stats,\n      .ols-course-cta-topic4 .ols-course-cta-features {\n        grid-template-columns: 1fr;\n      }\n\n      .ols-course-cta-topic4 .ols-course-button {\n        width: 100%;\n      }\n    }\n\n    \/* OLS saved author profile block *\/\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      }\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:\n          0 14px 32px rgba(28,36,75,0.18),\n          0 0 0 1px rgba(28,36,75,0.10);\n        transition:\n          transform 0.25s ease,\n          box-shadow 0.25s ease;\n      }\n    \n      .ols-author:hover .ols-author-avatar-img{\n        transform:scale(1.04);\n        box-shadow:\n          0 20px 42px rgba(28,36,75,0.22),\n          0 0 0 1px rgba(28,36,75,0.10);\n      }\n    \n      .ols-author-content{\n        min-width:0;\n      }\n    \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:#1C244B;\n        letter-spacing:-0.03em;\n      }\n    \n      .ols-author-description{\n        margin:0;\n        font-size:17px;\n        line-height:1.7;\n        font-weight:300;\n        color:#667085;\n      }\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 !important;\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:\n          transform 0.22s ease,\n          box-shadow 0.22s ease;\n      }\n    \n      .ols-linkedin-pill::before{\n        content:\"\";\n        position:absolute;\n        top:0;\n        left:-120%;\n        width:100%;\n        height:100%;\n        background:linear-gradient(\n          120deg,\n          rgba(255,255,255,0) 0%,\n          rgba(255,255,255,0.28) 50%,\n          rgba(255,255,255,0) 100%\n        );\n        transition:left 0.7s ease;\n      }\n    \n      .ols-linkedin-pill:hover{\n        color:#ffffff !important;\n        transform:translateY(-3px) scale(1.03);\n        box-shadow:\n          0 16px 34px rgba(10,102,194,0.34),\n          0 0 0 6px rgba(10,102,194,0.10);\n      }\n    \n      .ols-linkedin-pill:hover::before{\n        left:120%;\n      }\n    \n      .ols-linkedin-icon{\n        width:18px;\n        height:18px;\n        display:block;\n        flex-shrink:0;\n      }\n    \n      @media (max-width:640px){\n    \n        .ols-author{\n          align-items:flex-start;\n          padding:22px 18px;\n          border-radius:22px;\n        }\n    \n        .ols-author-avatar-img{\n          width:72px;\n          height:72px;\n        }\n    \n        .ols-author-title{\n          font-size:24px;\n        }\n    \n        .ols-author-description{\n          font-size:15px;\n        }\n      }\n    \n      .ols-linkedin-pill:hover, .ols-linkedin-pill:focus { color:#ffffff !important; }\n    \n    .ols-figure-placeholder .ols-placeholder-box { border: 2px dashed #c9973a; background: #fffaf0; border-radius: 16px; padding: 26px 22px; font-weight: 700; color: #7a4b12; text-align: center; line-height: 1.6; }\n    .ols-figure-placeholder .ols-figure-image { background: transparent; }\n    .ols-figure-placeholder { background: #ffffff; border: 1px solid rgba(28, 36, 75, 0.12); border-radius: 22px; padding: 14px; margin: 18px 0 6px; }\n    .ols-figure-placeholder .ols-figure-caption p { margin: 10px 0 0; font-size: 14px; color: #667085; text-align: center; }\n<\/style>\n\n  <aside class=\"ols-sidebar\">\r\n  <div class=\"ols-sidebar-header\">\r\n    <h3>Revision Notes<\/h3>\r\n    <p>A Level Chemistry<\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Topic 6 Organic Chemistry I<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/\">Introduction to Organic Chemistry<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/iupac-rules\/\">IUPAC Rules<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/alkene\/\">Alkene<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/alcohol\/\">Alcohol<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/halogenoalkanes\/\">Halogenoalkanes<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/aldehyde\/\">Aldehyde<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/ketone\/\">Ketone<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/carboxylic-acid\/\">Carboxylic Acid<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/ester\/\">Ester<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/introduction-to-organic-chemistry\/isomerism\/\">Isomerism<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/\">Alkanes<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/crude-oil\/\">Alkanes from Crude Oil<\/a>\r\n\r\n            <ul class=\"ols-subtopic-list\">\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/crude-oil\/fractional-distillation\/\">Fractional Distillation<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/crude-oil\/cracking\/\">Cracking<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/crude-oil\/reforming\/\">Reforming<\/a>\r\n              <\/li>\r\n            <\/ul>\r\n          <\/li>\r\n\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/\">Alkanes as Fuel<\/a>\r\n\r\n            <ul class=\"ols-subtopic-list\">\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/combustion\/\">Combustion<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/oxides-of-sulfur\/\">Oxides of Sulfur<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/oxides-of-nitrogen\/\">Oxides of Nitrogen<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/catalytic-converter\/\">Catalytic Converter<\/a>\r\n              <\/li>\r\n            <\/ul>\r\n          <\/li>\r\n\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/alternative-fuel\/\">Alternative Fuel<\/a>\r\n          <\/li>\r\n\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/reactions\/\">Reactions of Alkanes<\/a>\r\n\r\n            <ul class=\"ols-subtopic-list\">\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/reactions\/free-radical-substitution\/\">Free Radical Substitution<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/reactions\/initiation\/\">Initiation<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/reactions\/propagation\/\">Propagation<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/reactions\/termination\/\">Termination<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/reactions\/further-substitution\/\">Further Substitution<\/a>\r\n              <\/li>\r\n            <\/ul>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/\">Alkenes<\/a>\r\n\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/alkene-bonding\/\">Alkene Bonding<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/geometric-isomerism\/\">Geometric Isomerism<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/electrophilic-addition-mechanism\/\">Electrophilic Addition Mechanism<\/a>\r\n          <\/li>\r\n\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/reactions-of-alkenes\/\">Reactions of Alkenes<\/a>\r\n\r\n            <ul class=\"ols-subtopic-list\">\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/reactions-of-alkenes\/halogens\/\">Halogens<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/reactions-of-alkenes\/hydrogen-halide\/\">Hydrogen Halide<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/reactions-of-alkenes\/bromine-water\/\">Bromine Water<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/reactions-of-alkenes\/hydrogen\/\">Hydrogen<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/reactions-of-alkenes\/steam\/\">Steam<\/a>\r\n              <\/li>\r\n              <li>\r\n                <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/reactions-of-alkenes\/kmno4\/\">KMnO4<\/a>\r\n              <\/li>\r\n            <\/ul>\r\n          <\/li>\r\n\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/polymerisation-reactions\/\">Polymerisation Reactions<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/polymer-waste\/\">Polymer Waste<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/halogenoalkanes\/\">Halogenoalkanes<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alcohols\/\">Alcohols<\/a>\r\n      <\/li>\r\n\r\n    <\/ul>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Next Topics<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-7-modern-analytical-techniques-i\/\">Topic 7 Modern Analytical Techniques I<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/\">Topic 5 Formulae, Equations &amp; Amounts<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-4-inorganic-chemistry-and-the-periodic-table\/\">Topic 4 Inorganic Chemistry &amp; The Periodic Table<\/a>\r\n      <\/li>\r\n    <\/ul>\r\n  <\/div>\r\n<\/aside>\r\n\r\n<script>\r\n(function() {\r\n  function normalisePath(path) {\r\n    return String(path || '')\r\n      .split('?')[0]\r\n      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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\/\">Edexcel<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/\">Topic 6 Organic Chemistry I<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/\">Alkanes<\/a> \/\n        <span>Combustion<\/span>\n      <\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Combustion of Alkanes<\/h1>\n        <p class=\"ols-page-intro\">A concise revision guide to alkanes as fuels, complete combustion, incomplete combustion, carbon monoxide, soot, energy release and environmental impact.<\/p>\n\n        <div class=\"ols-badges\">\n          <div class=\"ols-badge\">Paper 2<\/div>\n          <div class=\"ols-badge\">Topic 6: Organic Chemistry I<\/div>\n          <div class=\"ols-badge\">9CH0\/02<\/div>\n        <\/div>\n      <\/header>\n<!-- 3D card: combustion-methane (22 Oct 2026) -->\n<!-- Copyright (c) 2026 Dr. Mohammed Al-Fatah, onlinelearningsystem.net. 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text-align:center; font-size:11px; font-style:italic; color:#aab0c0;\r\n}\r\n.ols-cc-cmb-001 a{color:#aab0c0; text-decoration:none;}\r\n.ols-cc-cmb-001 a:hover{text-decoration:underline;}\r\n.ols-cmb-001 .cmb-seg button{display:inline-flex; align-items:center;}\r\n.ols-cmb-001 .cmb-seg button .cmb-n{display:inline-flex; align-items:center; justify-content:center; width:20px; height:20px; margin-right:9px; border-radius:50%; font-size:11px; font-weight:600; background:rgba(37,99,235,0.10); color:#2563eb; flex:0 0 auto;}\r\n.ols-cmb-001 .cmb-seg button[aria-pressed=\"true\"] .cmb-n{background:#ffffff; color:#2563eb;}\r\n<\/style>\r\n\r\n<div class=\"cmb-head\">\r\n  <h2 class=\"cmb-title\">Burning Methane: Complete, Incomplete and Toxic CO<\/h2>\r\n  <p class=\"cmb-sub\">Choose a step to follow every atom as methane burns in plenty of oxygen, in too little, and in very little, then see why carbon monoxide is toxic.<\/p>\r\n<\/div>\r\n\r\n<div class=\"cmb-stage\" id=\"cmbStage\">\r\n  <canvas class=\"cmb-canvas\" id=\"cmbCanvas\"><\/canvas>\r\n  <div class=\"cmb-overlay\" id=\"cmbOverlay\"><\/div>\r\n  <div class=\"cmb-caption\" id=\"cmbCaption\"><\/div>\r\n  <div class=\"cmb-hint\" id=\"cmbHint\">Drag to rotate<\/div>\r\n  <div class=\"cmb-badges\" id=\"cmbBadges\"><\/div>\r\n<\/div>\r\n\r\n<div class=\"cmb-controls\">\r\n  <div class=\"cmb-row\">\r\n    <span class=\"cmb-rowlab\">Step<\/span>\r\n    <div class=\"cmb-seg\" role=\"group\" aria-label=\"Step\">\r\n      <button type=\"button\" data-step=\"1\" aria-pressed=\"true\"><span class=\"cmb-n\">1<\/span>Complete<\/button>\r\n      <button type=\"button\" data-step=\"2\" aria-pressed=\"false\"><span class=\"cmb-n\">2<\/span>Incomplete: CO<\/button>\r\n      <button type=\"button\" data-step=\"3\" aria-pressed=\"false\"><span class=\"cmb-n\">3<\/span>Soot<\/button>\r\n      <button type=\"button\" data-step=\"4\" aria-pressed=\"false\"><span class=\"cmb-n\">4<\/span>Why CO is toxic<\/button>\r\n    <\/div>\r\n  <\/div>\r\n\r\n  <div class=\"cmb-row\">\r\n    <span class=\"cmb-rowlab\">View<\/span>\r\n    <button type=\"button\" class=\"cmb-pill\" id=\"cmbResetV\">Reset view<\/button>\r\n  <\/div>\r\n<\/div>\r\n\r\n<div class=\"cmb-info\">\r\n  <h3 id=\"cmbInfoTitle\"><\/h3>\r\n  <p id=\"cmbInfoText\"><\/p>\r\n  <div class=\"cmb-facts\" id=\"cmbFacts\"><\/div>\r\n  <div class=\"cmb-key\">\r\n    <span><i class=\"k-ball\" style=\"background:#464a54\"><\/i>Carbon<\/span>\r\n    <span><i class=\"k-ball\" style=\"background:#ececf0\"><\/i>Hydrogen<\/span>\r\n    <span><i class=\"k-ball\" style=\"background:#cd2d28\"><\/i>Oxygen<\/span>\r\n    <span><i class=\"k-ball\" style=\"background:#be6432\"><\/i>Iron<\/span>\r\n    <span><i class=\"k-ball\" style=\"background:#3c5cc8\"><\/i>Nitrogen<\/span>\r\n  <\/div>\r\n<\/div>\r\n\r\n<script src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/JS\/combustion-methane.js?v=20261025p\"><\/script>\r\n<\/section>\r\n\r\n<p class=\"ols-cc-cmb-001\">&copy; Dr. Mohammed Al-Fatah &#8211; <a href=\"https:\/\/www.onlinelearningsystem.net\" target=\"_blank\" rel=\"noopener\">onlinelearningsystem.net<\/a><\/p>\n\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: Hydrocarbons and Energy Changes<\/h2>\n<p>Before you start, check what you remember from GCSE about hydrocarbons, bond energies and burning.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-content\" data-content-id=\"683\"><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">1<\/div>\n          <h2>Alkanes as Fuels<\/h2>\n        <\/div>\n\n        <p>A <strong>fuel<\/strong> is a substance that releases energy as heat when it undergoes combustion. Alkanes are useful fuels because they <strong>burn readily in oxygen<\/strong> and release large amounts of energy.<\/p>\n        <p>Combustion of alkanes is <strong>highly exothermic<\/strong>. More energy is released when new bonds are formed in the products than is absorbed to break bonds in the reactants.<\/p>\n        <p>This explains why alkanes are widely used in <strong>heating, cooking and transport<\/strong>, where a reliable and controllable energy source is required.<\/p>\n\n        <div class=\"ols-reaction-summary\">\n          <div class=\"ols-summary-item\"><span>Fuel<\/span><strong>Releases energy as heat during combustion<\/strong><\/div>\n          <div class=\"ols-summary-item\"><span>Alkanes<\/span><strong>Burn readily in oxygen<\/strong><\/div>\n          <div class=\"ols-summary-item\"><span>Energy change<\/span><strong>Highly exothermic<\/strong><\/div>\n          <div class=\"ols-summary-item\"><span>Uses<\/span><strong>Heating, cooking and transport<\/strong><\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Key idea:<\/strong> Alkanes are suitable fuels because their combustion releases significant energy in a controllable way.<\/p>\n        <\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Why Combustion Is Exothermic<\/h2>\n<p>Use the two energy totals to work out the overall energy change when propane burns.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-113\" class=\"h5p-iframe\" data-content-id=\"113\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Combustion of Alkanes MCQ: Bond Breaking and Bond Making for Propane\"><\/iframe><\/div><\/div>\n<\/section>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">2<\/div>\n          <h2>Complete Combustion<\/h2>\n        <\/div>\n\n        <p>When an alkane burns in the presence of <strong>excess oxygen<\/strong>, it undergoes <strong>complete combustion<\/strong>.<\/p>\n        <p>In complete combustion, the hydrocarbon is fully oxidised. The only products are <strong>carbon dioxide, CO<sub>2<\/sub><\/strong>, and <strong>water, H<sub>2<\/sub>O<\/strong>.<\/p>\n        <p>Because all carbon atoms form carbon dioxide and all hydrogen atoms form water, complete combustion releases the <strong>maximum amount of energy<\/strong> from the fuel.<\/p>\n\n        <div class=\"ols-definition-box\">\n          <p><strong>Complete combustion:<\/strong> Combustion in excess oxygen where a hydrocarbon is fully oxidised to carbon dioxide and water only.<\/p>\n        <\/div>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Combustion type<\/th>\n                <th>Oxygen supply<\/th>\n                <th>Products<\/th>\n                <th>Energy released<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td data-label=\"Combustion type\"><strong>Complete combustion<\/strong><\/td>\n                <td data-label=\"Oxygen supply\">Excess oxygen<\/td>\n                <td data-label=\"Products\">CO<sub>2<\/sub> and H<sub>2<\/sub>O only<\/td>\n                <td data-label=\"Energy released\">Maximum energy from the fuel<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Example:<\/strong> The complete combustion of octane is C<sub>8<\/sub>H<sub>18<\/sub>(l) + 12\u00bdO<sub>2<\/sub>(g) \u2192 8CO<sub>2<\/sub>(g) + 9H<sub>2<\/sub>O(l). Octane is a <strong>liquid<\/strong> under standard conditions, so it is written (l), like the water formed.<\/p>\n          <p><strong>Remember:<\/strong> If a question tells you not to use fractions, double every number: 2C<sub>8<\/sub>H<sub>18<\/sub>(l) + 25O<sub>2<\/sub>(g) \u2192 16CO<sub>2<\/sub>(g) + 18H<sub>2<\/sub>O(l).<\/p>\n        <\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Balance Complete Combustion<\/h2>\n<p>Type the missing balancing numbers for three alkanes burning in excess oxygen.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-112\" class=\"h5p-iframe\" data-content-id=\"112\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Combustion of Alkanes Fill the Blanks: Balancing Complete Combustion\"><\/iframe><\/div><\/div>\n<\/section>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">3<\/div>\n          <h2>Incomplete Combustion<\/h2>\n        <\/div>\n\n        <p>When the oxygen supply is <strong>limited<\/strong>, alkanes undergo <strong>incomplete combustion<\/strong> rather than complete combustion.<\/p>\n        <p>In incomplete combustion, the fuel is only <strong>partially oxidised<\/strong>. This can produce <strong>carbon monoxide, CO<\/strong>, which is highly toxic, and\/or <strong>solid carbon, C<\/strong>, also known as soot.<\/p>\n        <p>The oxygen supply is rarely even, so the products are usually a <strong>mixture<\/strong>: some carbon is oxidised to carbon dioxide, some only to carbon monoxide and some not at all.<\/p>\n<p>In an engine a little fuel also leaves the cylinder without burning, so the exhaust contains <strong>unburned hydrocarbons<\/strong> as well.<\/p>\n        <p>Incomplete combustion releases <strong>less energy per mole<\/strong> than complete combustion because the fuel is not fully oxidised.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Reaction<\/th>\n                <th>Balanced equation<\/th>\n                <th>Main concern<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td data-label=\"Reaction\"><strong>Methane forms carbon monoxide<\/strong><\/td>\n                <td data-label=\"Balanced equation\">CH<sub>4<\/sub>(g) + 1\u00bdO<sub>2<\/sub>(g) \u2192 CO(g) + 2H<sub>2<\/sub>O(l)<\/td>\n                <td data-label=\"Main concern\">CO is toxic and difficult to detect.<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Reaction\"><strong>Methane forms soot<\/strong><\/td>\n                <td data-label=\"Balanced equation\">CH<sub>4<\/sub>(g) + O<sub>2<\/sub>(g) \u2192 C(s) + 2H<sub>2<\/sub>O(l)<\/td>\n                <td data-label=\"Main concern\">Carbon particles cause smoky flames and air pollution.<\/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\/10\/t4-img-23-combustion.jpg\" alt=\"Two burners compared: plentiful air gives a blue flame, CO\u2082 and H\u2082O; limited air gives a yellow smoky flame, CO, soot and H\u2082O\" title=\"Incomplete combustion and soot formation\">\n          <\/div>\n          <div class=\"ols-figure-caption\">\n            <p>Limited oxygen causes partial oxidation, producing soot and carbon monoxide instead of only carbon dioxide and water.<\/p>\n          <\/div>\n        <\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Complete or Incomplete?<\/h2>\n<p>Read each balanced equation and decide quickly what it shows.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-114\" class=\"h5p-iframe\" data-content-id=\"114\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Combustion of Alkanes Quick Fire: Complete or Incomplete?\"><\/iframe><\/div><\/div>\n<\/section>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">4<\/div>\n          <h2>Carbon Monoxide and Health Risks<\/h2>\n        <\/div>\n\n        <p><strong>Carbon monoxide<\/strong> is a <strong>colourless and odourless gas<\/strong>. This makes it extremely dangerous because it can build up without being noticed.<\/p>\n        <p>If carbon monoxide accumulates in an enclosed space, such as a room with a faulty heater, it can be <strong>fatal<\/strong>.<\/p>\n        <p>Carbon monoxide is toxic because it forms a <strong>strong bond with haemoglobin<\/strong> in red blood cells. This bond is stronger than the bond between haemoglobin and oxygen, so oxygen is prevented from being transported around the body.<\/p>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Exam focus:<\/strong> A strong answer links carbon monoxide poisoning to haemoglobin and reduced oxygen transport, not just to \u201ctoxic fumes\u201d.<\/p>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n<div class=\"ols-figure-image\"><img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/fix-38.jpg\" alt=\"Two-panel diagram: oxygen carried on haemoglobin, versus carbon monoxide bound in its place so oxygen cannot be carried.\"><\/div>\n<div class=\"ols-figure-caption\"><p>Carbon monoxide is dangerous because it binds strongly to haemoglobin, reducing the blood\u2019s ability to transport oxygen.<\/p><\/div>\n<\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Explain the Danger<\/h2>\n<p>Write a short explanation, then compare it with the mark points and the model answer.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-115\" class=\"h5p-iframe\" data-content-id=\"115\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Combustion of Alkanes Explain: The Butane Heater in a Closed Tent\"><\/iframe><\/div><\/div>\n<\/section>\n\n      <article class=\"ols-note-card soft\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">5<\/div>\n          <h2>Energy and Environmental Impact<\/h2>\n        <\/div>\n\n        <p>Incomplete combustion releases <strong>less energy per mole<\/strong> than complete combustion because the carbon atoms are not fully oxidised to carbon dioxide.<\/p>\n        <p>The formation of <strong>carbon particles<\/strong> contributes to <strong>air pollution<\/strong>. These particles can produce a smoky or sooty flame.<\/p>\n        <p>Carbon particles can also contribute to <strong>global dimming<\/strong>, because the particles reflect or absorb some of the Sun\u2019s incoming radiation, so less of it reaches the ground.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Issue<\/th>\n                <th>Cause<\/th>\n                <th>Effect<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td data-label=\"Issue\"><strong>Lower energy release<\/strong><\/td>\n                <td data-label=\"Cause\">Fuel is only partially oxidised<\/td>\n                <td data-label=\"Effect\">Less energy released per mole than complete combustion<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Issue\"><strong>Air pollution<\/strong><\/td>\n                <td data-label=\"Cause\">Carbon particles are produced<\/td>\n                <td data-label=\"Effect\">Smoky flame and particulate pollution<\/td>\n              <\/tr>\n              <tr>\n                <td data-label=\"Issue\"><strong>Global dimming<\/strong><\/td>\n                <td data-label=\"Cause\">Soot particles reflect or absorb sunlight<\/td>\n                <td data-label=\"Effect\">Less sunlight reaches the ground<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n      <\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Pick the Accurate Statement<\/h2>\n<p>In each round, choose the one statement that is accurate.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-684\" class=\"h5p-iframe\" data-content-id=\"684\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Combustion of Alkanes Summary: Energy, Soot and Common Misconceptions\"><\/iframe><\/div><\/div>\n<\/section>\n\n      \n\n      <section class=\"ols-infographic-full\" aria-label=\"Combustion of alkanes summary\">\n        <h2 class=\"ols-infographic-title\">Combustion of Alkanes<\/h2>\n        <div class=\"ols-infographic-full-frame\">\n          <div class=\"ols-infographic-grid\">\n            <div class=\"ols-info-panel\">\n              <h3>Alkanes as fuels<\/h3>\n              <p>Alkanes burn in oxygen and release heat energy, making them useful fuels for heating, cooking and transport.<\/p>\n            <\/div>\n            <div class=\"ols-info-panel\">\n              <h3>Complete combustion<\/h3>\n              <p>With excess oxygen, alkanes form carbon dioxide and water only, releasing the maximum energy from the fuel.<\/p>\n            <\/div>\n            <div class=\"ols-info-panel\">\n              <h3>Incomplete combustion<\/h3>\n              <p>With limited oxygen, alkanes may form carbon monoxide and soot, releasing less energy per mole.<\/p>\n            <\/div>\n            <div class=\"ols-info-panel\">\n              <h3>Carbon monoxide risk<\/h3>\n              <p>Carbon monoxide binds strongly to haemoglobin, preventing oxygen transport and making it highly dangerous.<\/p>\n            <\/div>\n          <\/div>\n        <\/div>\n      <\/section>\n\n      <section class=\"ols-faq-card\">\n        <h2>Combustion FAQs<\/h2>\n        <p>These questions cover the main exam points on alkane combustion.<\/p>\n\n        <div class=\"ols-faq-list\">\n          <div class=\"ols-faq-item\">\n            <h3>What is complete combustion of an alkane?<\/h3>\n            <p>Complete combustion occurs when an alkane burns in excess oxygen, producing carbon dioxide and water only.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>What is incomplete combustion of an alkane?<\/h3>\n            <p>Incomplete combustion occurs when the oxygen supply is limited, producing carbon monoxide and\/or solid carbon as well as water.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why is carbon monoxide dangerous?<\/h3>\n            <p>Carbon monoxide binds strongly to haemoglobin in red blood cells, preventing oxygen from being transported around the body.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why does incomplete combustion release less energy?<\/h3>\n            <p>Incomplete combustion releases less energy because the fuel is only partially oxidised, so less energy is released per mole than in complete combustion.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>How do I balance the combustion equation of an alkane?<\/h3>\n            <p>Balance carbon first to give CO\u2082, then hydrogen to give H\u2082O. Count the oxygen atoms on the right and halve that number for O\u2082. A half is allowed, as in 12\u00bdO\u2082 for octane.<\/p>\n          <\/div>\n        <\/div>\n      <\/section>\n\n      <!-- author card (moved to the end, 10 Oct 2026) -->\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\n                class=\"ols-linkedin-pill\"\n                href=\"https:\/\/www.linkedin.com\/in\/doctormohammedfatah\/\"\n                target=\"_blank\"\n                rel=\"noopener noreferrer\"\n              >\n        \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        \n                View LinkedIn Profile\n        \n              <\/a>\n        \n            <\/div>\n        \n          <\/div>\n\n\n      <section class=\"ols-related-card\">\n        <h2>Related Topics<\/h2>\n        <p>Continue your revision with the next parts of Topic 6 and the following connected topics.<\/p>\n\n        <div class=\"ols-related-grid\">\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/oxides-of-sulfur\/\">Oxides of Sulfur<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/oxides-of-nitrogen\/\">Oxides of Nitrogen<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/catalytic-converter\/\">Catalytic Converter<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkenes\/alkene-bonding\/\">Alkenes<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-2-bonding-and-structure\/intermolecular-forces\/\">Intermolecular Forces<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-3-redox-i\/\">Redox Chemistry<\/a>\n        <\/div>\n      <\/section>\n\n      <!-- OLS Author Copyright Footprint \/ Attribution Card -->\n      <section class=\"ols-attribution-card ols-attr-std\" aria-label=\"Copyright notice\">\n<style id=\"ols-attribution-card-css\">.ols-attribution-card.ols-attr-std{background:linear-gradient(135deg,#ffffff,#f8fbff);border:1px solid rgba(28,36,75,0.14);border-radius:28px;box-shadow:0 18px 45px rgba(28,36,75,0.10);padding:34px;margin:24px 0;overflow:hidden;font-family:Poppins,Arial,sans-serif;box-sizing:border-box}.ols-attribution-card.ols-attr-std *{box-sizing:border-box}.ols-attribution-card.ols-attr-std p{margin:0;font-size:14px;line-height:1.65;font-weight:300;color:#667085}.ols-attribution-card.ols-attr-std strong{font-weight:700;color:#1C244B}@media (max-width:760px){.ols-attribution-card.ols-attr-std{padding:24px 18px;border-radius:22px}}<\/style>\n<p><strong>Copyright notice:<\/strong> This OLS revision content, including the explanations, layout, diagrams, tables and embedded learning structure, is authored for Online Learning System by Dr. Mohammed Al-Fatah. It may not be copied, reproduced, redistributed or adapted without written permission.<\/p>\n<\/section>\n\n      <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\/topic-6-organic-chemistry-i\/alkanes\/fuel\/combustion\/#webpage\",\n            \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/alkanes\/fuel\/combustion\/\",\n            \"name\": \"Combustion of Alkanes - Edexcel A Level Chemistry Revision Notes\",\n            \"description\": \"Revision notes on combustion of alkanes, complete combustion, incomplete combustion, carbon monoxide, soot, energy release and environmental impact for Edexcel A Level Chemistry.\",\n            \"inLanguage\": \"en-GB\",\n            \"isPartOf\": {\n  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Paper 2 Topic 6: Organic Chemistry I 9CH0\/02 Burning Methane: Complete, Incomplete and Toxic [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":4826,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-4827","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4827","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=4827"}],"version-history":[{"count":1,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4827\/revisions"}],"predecessor-version":[{"id":24540,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4827\/revisions\/24540"}],"up":[{"embeddable":true,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4826"}],"wp:attachment":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/media?parent=4827"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}