{"id":4956,"date":"2026-03-10T10:12:32","date_gmt":"2026-06-04T04:41:32","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/cp-1-molar-volume-of-a-gas\/"},"modified":"2026-06-09T10:22:59","modified_gmt":"2026-06-09T09:22:59","slug":"cp-1-molar-volume-of-a-gas","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/","title":{"rendered":"CP 1 Molar Volume of a Gas"},"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-revision-page ols-cp1-molar-volume-page\">\n  <style>\n    .ols-revision-page {\n      --navy: #1C244B;\n      --blue: #2563eb;\n      --soft-blue: #eef4ff;\n      --soft-green: #f0f7f1;\n      --soft-purple: #f7f0ff;\n      --soft-orange: #fff7ed;\n      --soft-red: #fff7f7;\n      --green: #168a2d;\n      --orange: #ea7600;\n      --red: #d92d20;\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 * {\n      box-sizing: border-box;\n    }\n\n    .ols-revision-layout {\n      display: grid;\n      grid-template-columns: 310px minmax(0, 1fr);\n      gap: 34px;\n      max-width: 1450px;\n      margin: 0 auto;\n      padding: 24px 20px 60px;\n      overflow: visible;\n    }\n\n    .ols-sidebar {\n      position: sticky;\n      top: 20px;\n      align-self: start;\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 24px;\n      box-shadow: var(--shadow);\n      overflow: hidden;\n    }\n\n    .ols-sidebar-header {\n      padding: 22px;\n      border-bottom: 1px solid var(--border);\n      background: linear-gradient(135deg, #ffffff, var(--soft-blue));\n    }\n\n    .ols-sidebar-header h3 {\n      margin: 0 0 6px;\n      font-size: 21px;\n      font-weight: 700;\n      color: var(--navy);\n    }\n\n    .ols-sidebar-header p {\n      margin: 0;\n      font-size: 14px;\n      color: var(--grey-text);\n      line-height: 1.5;\n    }\n\n    .ols-topic-group {\n      padding: 18px 22px;\n      border-bottom: 1px solid var(--border);\n    }\n\n    .ols-topic-group:last-child {\n      border-bottom: none;\n    }\n\n    .ols-topic-group h4 {\n      margin: 0 0 14px;\n      font-size: 17px;\n      font-weight: 700;\n      color: var(--navy);\n    }\n\n    .ols-topic-list {\n      list-style: none;\n      margin: 0;\n      padding: 0;\n      display: grid;\n      gap: 8px;\n    }\n\n    .ols-topic-list li {\n      border-radius: 14px;\n      font-size: 15px;\n      line-height: 1.35;\n      color: #344054;\n      background: transparent;\n    }\n\n    .ols-topic-list li.active {\n      padding: 11px 12px;\n      background: var(--soft-blue);\n      color: var(--blue);\n      font-weight: 700;\n    }\n\n    .ols-topic-list li:not(.active) {\n      padding: 0;\n    }\n\n    .ols-topic-list a {\n      display: block;\n      padding: 11px 12px;\n      border-radius: 14px;\n      color: #344054;\n      text-decoration: none;\n      transition: background 0.2s ease, color 0.2s ease;\n    }\n\n    .ols-topic-list a:hover {\n      background: var(--soft-blue);\n      color: var(--blue);\n    }\n\n    .ols-main {\n      min-width: 0;\n      max-width: 970px;\n      overflow: visible;\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-related-card,\n    .ols-faq-card,\n    .ols-author-footprint {\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: visible;\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-author {\n      display: flex;\n      align-items: center;\n      gap: 20px;\n      padding: 28px;\n      border-radius: 28px;\n      background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid rgba(28, 36, 75, 0.12);\n      box-shadow: 0 18px 45px rgba(28, 36, 75, 0.10);\n      margin-top: 22px;\n    }\n\n    .ols-author-avatar-img {\n      width: 92px;\n      height: 92px;\n      border-radius: 50%;\n      object-fit: cover;\n      object-position: center;\n      flex-shrink: 0;\n      border: 4px solid #ffffff;\n      box-shadow: 0 14px 32px rgba(28, 36, 75, 0.18), 0 0 0 1px rgba(28, 36, 75, 0.10);\n    }\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: var(--navy);\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: var(--grey-text);\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;\n      text-decoration: none;\n      font-size: 14px;\n      line-height: 1;\n      font-weight: 700;\n      box-shadow: 0 10px 22px rgba(10, 102, 194, 0.24);\n      transition: transform 0.22s ease, box-shadow 0.22s ease;\n    }\n\n    .ols-linkedin-pill:hover {\n      transform: translateY(-3px) scale(1.03);\n      box-shadow: 0 16px 34px rgba(10, 102, 194, 0.34), 0 0 0 6px rgba(10, 102, 194, 0.10);\n      color: #ffffff;\n    }\n\n    .ols-linkedin-icon {\n      width: 18px;\n      height: 18px;\n      display: block;\n      flex-shrink: 0;\n    }\n\n    .ols-note-card.soft {\n      background: linear-gradient(135deg, #ffffff 0%, var(--soft-blue) 100%);\n    }\n\n    .ols-note-card.green {\n      background: linear-gradient(135deg, #ffffff 0%, var(--soft-green) 100%);\n    }\n\n    .ols-note-card.orange {\n      background: linear-gradient(135deg, #ffffff 0%, var(--soft-orange) 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-related-card h2,\n    .ols-faq-card h2,\n    .ols-infographic-title,\n    .ols-widget-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-note-card p,\n    .ols-note-card li,\n    .ols-h5p-card p,\n    .ols-related-card p,\n    .ols-faq-card p,\n    .ols-faq-card li,\n    .ols-author-footprint p {\n      font-size: clamp(15px, 1.25vw, 17px);\n      line-height: 1.65;\n      font-weight: 300;\n      color: var(--body-text);\n    }\n\n    .ols-note-card strong,\n    .ols-h5p-card strong,\n    .ols-related-card strong,\n    .ols-faq-card strong,\n    .ols-author-footprint strong {\n      font-weight: 700;\n      color: var(--navy);\n    }\n\n    .ols-note-card ul,\n    .ols-note-card ol,\n    .ols-faq-card ul {\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-warning-box {\n      margin-top: 20px;\n      background: #fff5f5;\n      border: 1px solid rgba(217, 45, 32, 0.22);\n      border-radius: 20px;\n      padding: 18px 20px;\n    }\n\n    .ols-warning-box p {\n      margin: 0;\n      font-weight: 400;\n      color: var(--navy);\n    }\n\n    .ols-equation-box {\n      margin-top: 18px;\n      background: #ffffff;\n      border: 1px solid rgba(28, 36, 75, 0.12);\n      border-radius: 18px;\n      padding: 16px 18px;\n      box-shadow: var(--inner-shadow);\n      font-size: clamp(16px, 1.4vw, 19px);\n      line-height: 1.7;\n      color: var(--navy);\n      font-weight: 500;\n      overflow-wrap: anywhere;\n    }\n\n    .ols-figure-card {\n      margin: 26px 0 4px;\n      border: 1px solid var(--border);\n      border-radius: 26px;\n      background: #ffffff;\n      box-shadow: var(--inner-shadow);\n      overflow: visible;\n      position: relative;\n      z-index: 2;\n    }\n\n    .ols-figure-link {\n      display: block;\n      text-decoration: none;\n      color: inherit;\n      border-radius: 26px 26px 0 0;\n      overflow: visible;\n      position: relative;\n      z-index: 3;\n    }\n\n    .ols-figure-image {\n      width: 100%;\n      min-height: 330px;\n      display: flex;\n      align-items: center;\n      justify-content: center;\n      background: #ffffff;\n      padding: 18px;\n      overflow: visible;\n      border-radius: 26px 26px 0 0;\n    }\n\n    .ols-figure-image img {\n      max-width: 100%;\n      height: auto;\n      display: block;\n      border-radius: 18px;\n      transition: transform 0.24s ease, box-shadow 0.24s ease;\n      transform-origin: center center;\n      position: relative;\n      z-index: 4;\n    }\n\n    .ols-figure-link:hover img {\n      transform: scale(1.5);\n      box-shadow: 0 24px 60px rgba(28, 36, 75, 0.22);\n      z-index: 20;\n    }\n\n    .ols-figure-caption {\n      padding: 20px 24px 22px;\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n      border-radius: 0 0 26px 26px;\n    }\n\n    .ols-figure-caption p {\n      margin: 0;\n      color: #5f6b85;\n      font-size: clamp(14px, 1.2vw, 16px);\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: 15px;\n      text-align: left;\n      font-size: clamp(14px, 1.1vw, 16px);\n      font-weight: 600;\n      overflow-wrap: anywhere;\n    }\n\n    .ols-table td {\n      padding: 15px;\n      border-bottom: 1px solid var(--border);\n      font-size: clamp(14px, 1.1vw, 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-method-grid {\n      display: grid;\n      grid-template-columns: 1fr;\n      gap: 12px;\n      margin-top: 20px;\n    }\n\n    .ols-method-step {\n      display: grid;\n      grid-template-columns: 44px minmax(0, 1fr);\n      gap: 14px;\n      align-items: start;\n      padding: 16px;\n      border-radius: 18px;\n      border: 1px solid var(--border);\n      background: #ffffff;\n      box-shadow: 0 8px 18px rgba(28, 36, 75, 0.06);\n    }\n\n    .ols-step-number {\n      width: 36px;\n      height: 36px;\n      border-radius: 50%;\n      display: grid;\n      place-items: center;\n      background: var(--blue);\n      color: #ffffff;\n      font-weight: 800;\n      font-size: 16px;\n    }\n\n    .ols-method-step p {\n      margin: 0;\n    }\n\n    .ols-pill-row {\n      display: flex;\n      flex-wrap: wrap;\n      gap: 10px;\n      margin-top: 18px;\n    }\n\n    .ols-mini-pill {\n      display: inline-flex;\n      align-items: center;\n      border-radius: 999px;\n      border: 1px solid var(--border);\n      padding: 8px 12px;\n      background: #ffffff;\n      color: var(--navy);\n      font-size: 14px;\n      font-weight: 600;\n    }\n\n    .ols-interactive-card {\n      background: linear-gradient(135deg, #ffffff 0%, #f8fbff 100%);\n      border: 1px solid var(--border);\n      border-radius: 28px;\n      box-shadow: var(--shadow);\n      padding: 30px;\n      margin-bottom: 24px;\n      overflow: hidden;\n    }\n\n    .ols-widget-intro {\n      margin: 12px 0 22px;\n      font-size: clamp(15px, 1.25vw, 17px);\n      line-height: 1.65;\n      color: var(--body-text);\n      font-weight: 300;\n    }\n\n    .ols-gas-widget {\n      display: grid;\n      grid-template-columns: 260px minmax(0, 1fr);\n      gap: 20px;\n      align-items: start;\n    }\n\n    .ols-gas-widget-panel {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 22px;\n      box-shadow: var(--inner-shadow);\n      padding: 18px;\n    }\n\n    .ols-gas-widget-panel h3 {\n      margin: 0 0 12px;\n      font-size: 19px;\n      color: var(--navy);\n      line-height: 1.25;\n    }\n\n    .ols-widget-table {\n      width: 100%;\n      border-collapse: collapse;\n      table-layout: fixed;\n      font-size: 13px;\n    }\n\n    .ols-widget-table th {\n      background: var(--navy);\n      color: #ffffff;\n      padding: 8px;\n      text-align: center;\n      font-weight: 600;\n    }\n\n    .ols-widget-table td {\n      border: 1px solid rgba(28, 36, 75, 0.12);\n      padding: 8px;\n      text-align: center;\n      color: var(--body-text);\n    }\n\n    .ols-widget-controls {\n      display: grid;\n      gap: 10px;\n      margin-top: 16px;\n    }\n\n    @keyframes ols-widget-btn-pulse {\n      0%, 100% {\n        transform: scale(1);\n        box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.34);\n      }\n      50% {\n        transform: scale(1.035);\n        box-shadow: 0 0 0 8px rgba(37, 99, 235, 0);\n      }\n    }\n\n    .ols-widget-btn {\n      width: 100%;\n      border: none;\n      border-radius: 999px;\n      padding: 11px 14px;\n      background: var(--navy);\n      color: #ffffff;\n      font-family: Poppins, Arial, sans-serif;\n      font-size: 14px;\n      font-weight: 700;\n      cursor: pointer;\n      transition: transform 0.2s ease, background 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;\n    }\n\n    .ols-widget-btn.is-pulsing {\n      background: var(--blue);\n      animation: ols-widget-btn-pulse 1.8s ease-in-out infinite;\n      box-shadow: 0 10px 22px rgba(37, 99, 235, 0.18);\n    }\n\n    .ols-widget-btn.is-locked {\n      background: #98a2b3;\n      color: #ffffff;\n      opacity: 0.55;\n      cursor: not-allowed;\n      animation: none;\n      box-shadow: none;\n    }\n\n    .ols-widget-btn.is-complete {\n      background: #475467;\n      color: #ffffff;\n      animation: none;\n      box-shadow: none;\n    }\n\n    .ols-widget-btn.is-reset {\n      background: #ffffff;\n      color: var(--navy);\n      border: 1px solid var(--border);\n      animation: none;\n      box-shadow: none;\n    }\n\n    .ols-widget-btn:not(.is-locked):hover {\n      transform: translateY(-1px);\n      background: var(--blue);\n      animation: none;\n      box-shadow: 0 10px 22px rgba(37, 99, 235, 0.24);\n    }\n\n    .ols-widget-btn.is-reset:hover {\n      background: var(--soft-blue);\n      color: var(--blue);\n    }\n\n    .ols-slider-label {\n      display: grid;\n      gap: 8px;\n      margin-top: 14px;\n      font-size: 14px;\n      font-weight: 600;\n      color: var(--navy);\n    }\n\n    .ols-slider-label input {\n      width: 100%;\n    }\n\n    .ols-graph-stage {\n      background: #ffffff;\n      border: 1px solid var(--border);\n      border-radius: 22px;\n      padding: 16px;\n      box-shadow: var(--inner-shadow);\n    }\n\n    .ols-graph-stage svg {\n      width: 100%;\n      height: auto;\n      display: block;\n      background: #ffffff;\n      border-radius: 16px;\n    }\n\n    .ols-widget-feedback {\n      margin-top: 14px;\n      background: var(--soft-green);\n      border: 1px solid rgba(63, 143, 70, 0.25);\n      border-radius: 18px;\n      padding: 14px 16px;\n      color: var(--navy);\n      font-size: 14px;\n      line-height: 1.6;\n      min-height: 58px;\n    }\n\n    .ols-infographic-full {\n      width: 100%;\n      max-width: 100%;\n      margin: 6px 0 30px;\n      overflow: visible;\n    }\n\n    .ols-infographic-title {\n      margin-bottom: 18px;\n    }\n\n    .ols-infographic-full-frame {\n      width: 100%;\n      max-width: 100%;\n      border-radius: 22px;\n      background: #ffffff;\n      border: 1px solid var(--border);\n      box-shadow: 0 18px 42px rgba(28, 36, 75, 0.13);\n      overflow: visible;\n    }\n\n    .ols-infographic-full-frame a {\n      display: block;\n      overflow: visible;\n      border-radius: 22px;\n    }\n\n    .ols-infographic-full-frame img {\n      width: 100%;\n      max-width: 100%;\n      height: auto;\n      display: block;\n      object-fit: contain;\n      border-radius: 22px;\n      transition: transform 0.24s ease, box-shadow 0.24s ease;\n      position: relative;\n      z-index: 3;\n    }\n\n    .ols-infographic-full-frame a:hover img {\n      transform: scale(1.08);\n      box-shadow: 0 24px 60px rgba(28, 36, 75, 0.18);\n      z-index: 10;\n    }\n\n    .ols-h5p-card {\n      background: linear-gradient(135deg, #ffffff 0%, var(--soft-purple) 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-unlock {\n      background: linear-gradient(135deg, var(--navy), #0f4fa8);\n      border-radius: 30px;\n      padding: 36px;\n      color: #ffffff;\n      box-shadow: var(--shadow);\n      text-align: center;\n      margin: 30px 0 24px;\n    }\n\n    .ols-unlock h2 {\n      margin: 0 0 12px;\n      font-size: clamp(30px, 4vw, 46px);\n      line-height: 1.15;\n      font-weight: 800;\n      color: #ffffff;\n      text-align: center;\n    }\n\n    .ols-unlock p {\n      margin: 0 auto 24px;\n      max-width: 700px;\n      font-size: 20px;\n      line-height: 1.6;\n      font-weight: 300;\n      text-align: center;\n      color: #ffffff;\n    }\n\n    .ols-cta-button {\n      display: inline-flex;\n      align-items: center;\n      justify-content: center;\n      padding: 14px 26px;\n      border-radius: 999px;\n      background: #ffffff;\n      color: var(--navy);\n      text-decoration: none;\n      font-weight: 700;\n      transition: background 0.2s ease, color 0.2s ease, transform 0.2s ease;\n    }\n\n    .ols-cta-button:hover {\n      background: #f8fbff;\n      color: var(--blue);\n      transform: translateY(-1px);\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: 1.3;\n      color: var(--navy);\n    }\n\n    .ols-faq-item p {\n      margin: 0;\n      font-size: 16px;\n      line-height: 1.65;\n      color: var(--body-text);\n    }\n\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-author-footprint {\n      background: linear-gradient(135deg, #ffffff, #f8fbff);\n    }\n\n    .ols-author-footprint p {\n      margin: 0;\n      font-size: 14px;\n      color: var(--grey-text);\n    }\n\n    .ols-lightbox {\n      position: fixed;\n      inset: 0;\n      background: rgba(15, 23, 42, 0.88);\n      z-index: 99999;\n      display: none;\n      align-items: center;\n      justify-content: center;\n      padding: 24px;\n    }\n\n    .ols-lightbox.is-open {\n      display: flex;\n    }\n\n    .ols-lightbox img {\n      max-width: min(96vw, 1500px);\n      max-height: 90vh;\n      width: auto;\n      height: auto;\n      border-radius: 18px;\n      background: #ffffff;\n      box-shadow: 0 25px 80px rgba(0, 0, 0, 0.45);\n    }\n\n    .ols-lightbox button {\n      position: absolute;\n      top: 18px;\n      right: 18px;\n      border: none;\n      border-radius: 999px;\n      width: 44px;\n      height: 44px;\n      background: #ffffff;\n      color: var(--navy);\n      font-size: 28px;\n      font-weight: 700;\n      cursor: pointer;\n      line-height: 1;\n    }\n\n    @media (max-width: 1050px) {\n      .ols-revision-layout {\n        grid-template-columns: 1fr;\n      }\n\n      .ols-sidebar {\n        position: relative;\n        top: auto;\n      }\n\n      .ols-topic-list {\n        grid-template-columns: repeat(2, minmax(0, 1fr));\n      }\n\n      .ols-main {\n        max-width: none;\n      }\n\n      .ols-gas-widget {\n        grid-template-columns: 1fr;\n      }\n\n      .ols-related-grid {\n        grid-template-columns: repeat(2, minmax(0, 1fr));\n      }\n    }\n\n    @media (max-width: 760px) {\n      .ols-revision-layout {\n        padding: 14px 12px 44px;\n      }\n\n      .ols-title-card,\n      .ols-note-card,\n      .ols-h5p-card,\n      .ols-related-card,\n      .ols-faq-card,\n      .ols-unlock,\n      .ols-author-footprint,\n      .ols-interactive-card {\n        padding: 24px 18px;\n        border-radius: 22px;\n      }\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      .ols-note-title {\n        align-items: flex-start;\n      }\n\n      .ols-figure-image {\n        min-height: 220px;\n        padding: 12px;\n      }\n\n      .ols-figure-link:hover img {\n        transform: scale(1.08);\n      }\n\n      .ols-infographic-full-frame a:hover img {\n        transform: scale(1.04);\n      }\n\n      .ols-topic-list,\n      .ols-related-grid {\n        grid-template-columns: 1fr;\n      }\n\n      .ols-table th,\n      .ols-table td {\n        padding: 12px 10px;\n      }\n    }\n  <\/style>\n\n  <div class=\"ols-revision-layout\">\n    <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>\n\n\n    <main class=\"ols-main\">\n      <nav class=\"ols-breadcrumbs\" aria-label=\"Breadcrumb\">\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\">Revision Notes<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\">A Level Chemistry<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\">Edexcel International<\/a> \/\n        <span>CP1 Molar Volume of a Gas<\/span>\n      <\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Core Practical 1: Molar Volume of a Gas<\/h1>\n        <p class=\"ols-page-intro\">A guided Edexcel International AS Chemistry revision walkthrough for measuring the molar volume of carbon dioxide using calcium carbonate, ethanoic acid, gas collection over water, graphing and mole calculations.<\/p>\n\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>\n\n        <div class=\"ols-author\">\n          <img decoding=\"async\" class=\"ols-author-avatar-img\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\" alt=\"Dr. Mohammed Al-Fatah\">\n\n          <div class=\"ols-author-content\">\n            <h2 class=\"ols-author-title\">Written by: Dr. Mohammed Al-Fatah<\/h2>\n            <p class=\"ols-author-description\">Chemistry specialist revision notes for A Level Chemistry.<\/p>\n\n            <a class=\"ols-linkedin-pill\" href=\"https:\/\/www.linkedin.com\/in\/doctormohammedfatah\/\" target=\"_blank\" rel=\"noopener noreferrer\">\n              <svg class=\"ols-linkedin-icon\" viewBox=\"0 0 24 24\" fill=\"currentColor\" aria-hidden=\"true\">\n                <path d=\"M4.98 3.5C4.98 4.88 3.86 6 2.48 6S0 4.88 0 3.5 1.12 1 2.48 1s2.5 1.12 2.5 2.5zM.5 8h4V24h-4V8zm7 0h3.8v2.2h.1c.5-.9 1.8-2.2 3.9-2.2 4.2 0 5 2.8 5 6.4V24h-4v-7.6c0-1.8 0-4.2-2.6-4.2s-3 2-3 4v7.8h-4V8z\"><\/path>\n              <\/svg>\n              View LinkedIn Profile\n            <\/a>\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 Does This Practical Measure?<\/h2>\n        <\/div>\n\n        <p>The aim of this core practical is to find the <strong>volume occupied by one mole of carbon dioxide gas<\/strong>. The experiment produces carbon dioxide by reacting calcium carbonate with ethanoic acid, then measures the volume of gas collected.<\/p>\n\n        <p>Different masses of calcium carbonate produce different volumes of carbon dioxide. These results are plotted on a graph, then the graph is used to estimate the volume of carbon dioxide made from <strong>0.25 g of CaCO<sub>3<\/sub><\/strong>.<\/p>\n\n        <div class=\"ols-equation-box\">\n          CaCO<sub>3<\/sub>(s) + 2CH<sub>3<\/sub>COOH(aq) \u2192 Ca(CH<sub>3<\/sub>COO)<sub>2<\/sub>(aq) + CO<sub>2<\/sub>(g) + H<sub>2<\/sub>O(l)\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Key idea:<\/strong> One mole of calcium carbonate produces one mole of carbon dioxide, so the moles of CO<sub>2<\/sub> are equal to the moles of CaCO<sub>3<\/sub> used.<\/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>Measuring Gas Volumes<\/h2>\n        <\/div>\n\n        <p>Gas volumes can be measured using a <strong>gas syringe<\/strong> or by <strong>collecting gas over water<\/strong>. In this practical, carbon dioxide is collected over water in an upturned measuring cylinder.<\/p>\n\n        <p>A gas syringe can reduce some errors because the gas is measured directly without dissolving in water. Collection over water is still useful, but it is most suitable for gases that are not very soluble and do not react with water.<\/p>\n\n        <div class=\"ols-figure-card\">\n          <a class=\"ols-figure-link ols-lightbox-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/measuring-gas-volumes.webp\" aria-label=\"Open measuring gas volumes infographic\">\n            <div class=\"ols-figure-image\">\n              <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/measuring-gas-volumes.webp\" alt=\"Infographic comparing gas syringe collection and collecting gas over water for measuring gas volumes.\">\n            <\/div>\n          <\/a>\n          <div class=\"ols-figure-caption\">\n            <p>This visual compares gas syringes with collection over water, including common errors such as gas escape, syringe sticking and gases dissolving in water.<\/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\">3<\/div>\n          <h2>How the Apparatus Collects Carbon Dioxide<\/h2>\n        <\/div>\n\n        <p>The reaction takes place in a boiling tube or similar reaction vessel containing ethanoic acid. Calcium carbonate is added, the bung is replaced quickly, and carbon dioxide travels through the delivery tube into the upturned measuring cylinder.<\/p>\n\n        <p>The carbon dioxide collects at the top of the measuring cylinder and displaces water. The volume of gas collected is then read from the graduations in cm<sup>3<\/sup>.<\/p>\n\n        <div class=\"ols-figure-card\">\n          <a class=\"ols-figure-link ols-lightbox-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/collecting-gas-over-water.webp\" aria-label=\"Open collecting gas over water apparatus diagram\">\n            <div class=\"ols-figure-image\">\n              <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/collecting-gas-over-water.webp\" alt=\"Diagram showing carbon dioxide collected over water using a delivery tube, water trough and upturned measuring cylinder.\">\n            <\/div>\n          <\/a>\n          <div class=\"ols-figure-caption\">\n            <p>The delivery tube carries CO<sub>2<\/sub> into the inverted measuring cylinder, where the gas displaces water and its volume is read directly.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-warning-box\">\n          <p><strong>Practical warning:<\/strong> The bung must be replaced quickly after adding CaCO<sub>3<\/sub>. Any gas produced before the bung is fitted will escape and make the measured gas volume too low.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card orange\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">4<\/div>\n          <h2>Step-by-Step Method<\/h2>\n        <\/div>\n\n        <p>The method is designed so that the actual mass of calcium carbonate transferred into the reaction vessel is known accurately. This is why the test tube is weighed before and after tipping out the solid.<\/p>\n\n        <div class=\"ols-method-grid\">\n          <div class=\"ols-method-step\">\n            <div class=\"ols-step-number\">1<\/div>\n            <p>Set up the gas collection apparatus with the delivery tube leading into an upturned measuring cylinder filled with water.<\/p>\n          <\/div>\n\n          <div class=\"ols-method-step\">\n            <div class=\"ols-step-number\">2<\/div>\n            <p>Measure <strong>30 cm<sup>3<\/sup><\/strong> of <strong>1 mol dm<sup>-3<\/sup><\/strong> ethanoic acid and place it in the reaction vessel.<\/p>\n          <\/div>\n\n          <div class=\"ols-method-step\">\n            <div class=\"ols-step-number\">3<\/div>\n            <p>Place about <strong>0.05 g<\/strong> of powdered calcium carbonate into a test tube. Weigh the test tube and contents accurately.<\/p>\n          <\/div>\n\n          <div class=\"ols-method-step\">\n            <div class=\"ols-step-number\">4<\/div>\n            <p>Add the calcium carbonate to the ethanoic acid and quickly replace the bung to minimise gas loss.<\/p>\n          <\/div>\n\n          <div class=\"ols-method-step\">\n            <div class=\"ols-step-number\">5<\/div>\n            <p>When the reaction stops, record the volume of carbon dioxide collected in cm<sup>3<\/sup>.<\/p>\n          <\/div>\n\n          <div class=\"ols-method-step\">\n            <div class=\"ols-step-number\">6<\/div>\n            <p>Reweigh the test tube. The difference between the two masses gives the mass of CaCO<sub>3<\/sub> actually used.<\/p>\n          <\/div>\n\n          <div class=\"ols-method-step\">\n            <div class=\"ols-step-number\">7<\/div>\n            <p>Repeat using larger masses of CaCO<sub>3<\/sub>, increasing by about 0.05 g each time. Do not exceed 0.40 g.<\/p>\n          <\/div>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Why not exceed 0.40 g?<\/strong> Larger masses may produce more carbon dioxide than the 100 cm<sup>3<\/sup> measuring cylinder can hold.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">5<\/div>\n          <h2>Using the Experimental Data<\/h2>\n        <\/div>\n\n        <p>The raw results show how the volume of carbon dioxide changes as the mass of calcium carbonate increases. Experimental data is not perfectly neat, so the graph is used to find a more reliable trend.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Mass of CaCO<sub>3<\/sub> \/ g<\/th>\n                <th>Volume of CO<sub>2<\/sub> collected \/ cm<sup>3<\/sup><\/th>\n                <th>What the result shows<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td>0.05<\/td>\n                <td>11<\/td>\n                <td>Small mass gives a small gas volume.<\/td>\n              <\/tr>\n              <tr>\n                <td>0.11<\/td>\n                <td>27<\/td>\n                <td>Gas volume increases as mass increases.<\/td>\n              <\/tr>\n              <tr>\n                <td>0.17<\/td>\n                <td>32<\/td>\n                <td>This point is below the overall trend, showing experimental variation.<\/td>\n              <\/tr>\n              <tr>\n                <td>0.21<\/td>\n                <td>50<\/td>\n                <td>Close to the straight-line trend.<\/td>\n              <\/tr>\n              <tr>\n                <td>0.24<\/td>\n                <td>59<\/td>\n                <td>Useful point near the 0.25 g graph reading.<\/td>\n              <\/tr>\n              <tr>\n                <td>0.32<\/td>\n                <td>74<\/td>\n                <td>Higher mass gives a larger gas volume.<\/td>\n              <\/tr>\n              <tr>\n                <td>0.33<\/td>\n                <td>80<\/td>\n                <td>Close to the expected high-mass region.<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Graph rule:<\/strong> Plot mass of CaCO<sub>3<\/sub> on the x-axis and volume of CO<sub>2<\/sub> on the y-axis. The straight line of best fit should pass through the origin because zero CaCO<sub>3<\/sub> should produce zero CO<sub>2<\/sub>.<\/p>\n        <\/div>\n      <\/article>\n\n      <section class=\"ols-interactive-card\" id=\"ols-cp1-graph-widget\">\n        <h2 class=\"ols-widget-title\">Interactive Graph: From Data to Molar Volume<\/h2>\n        <p class=\"ols-widget-intro\">Use the buttons to build the graph step by step, read the volume at 0.25 g of CaCO<sub>3<\/sub>, and reveal how the molar volume calculation is completed.<\/p>\n\n        <div class=\"ols-gas-widget\">\n          <div class=\"ols-gas-widget-panel\">\n            <h3>Sample results<\/h3>\n            <table class=\"ols-widget-table\">\n              <thead>\n                <tr>\n                  <th>Mass \/ g<\/th>\n                  <th>CO<sub>2<\/sub> \/ cm<sup>3<\/sup><\/th>\n                <\/tr>\n              <\/thead>\n              <tbody>\n                <tr><td>0.05<\/td><td>11<\/td><\/tr>\n                <tr><td>0.11<\/td><td>27<\/td><\/tr>\n                <tr><td>0.17<\/td><td>32<\/td><\/tr>\n                <tr><td>0.21<\/td><td>50<\/td><\/tr>\n                <tr><td>0.24<\/td><td>59<\/td><\/tr>\n                <tr><td>0.32<\/td><td>74<\/td><\/tr>\n                <tr><td>0.33<\/td><td>80<\/td><\/tr>\n              <\/tbody>\n            <\/table>\n\n            <label class=\"ols-slider-label\" for=\"olsCp1MassSlider\">\n              Mass selected: <span id=\"olsCp1MassValue\">0.25<\/span> g\n              <input id=\"olsCp1MassSlider\" type=\"range\" min=\"0.05\" max=\"0.35\" step=\"0.01\" value=\"0.25\">\n            <\/label>\n\n            <div class=\"ols-widget-controls\">\n              <button class=\"ols-widget-btn is-pulsing\" type=\"button\" id=\"olsCp1PlotBtn\">Plot points<\/button>\n              <button class=\"ols-widget-btn is-locked\" type=\"button\" id=\"olsCp1LineBtn\" disabled=\"\">Draw line through origin<\/button>\n              <button class=\"ols-widget-btn is-locked\" type=\"button\" id=\"olsCp1ReadBtn\" disabled=\"\">Read volume<\/button>\n              <button class=\"ols-widget-btn is-locked\" type=\"button\" id=\"olsCp1CalcBtn\" disabled=\"\">Show calculation<\/button>\n              <button class=\"ols-widget-btn is-reset\" type=\"button\" id=\"olsCp1ResetBtn\">Reset<\/button>\n            <\/div>\n          <\/div>\n\n          <div class=\"ols-graph-stage\">\n            <svg id=\"olsCp1GraphSvg\" viewBox=\"0 0 680 460\" role=\"img\" aria-label=\"Interactive graph of mass of calcium carbonate against volume of carbon dioxide\">\n              <rect x=\"0\" y=\"0\" width=\"680\" height=\"460\" fill=\"#ffffff\"><\/rect>\n\n              <g id=\"olsCp1Grid\"><\/g>\n\n              <line x1=\"70\" y1=\"390\" x2=\"620\" y2=\"390\" stroke=\"#111827\" stroke-width=\"2\"><\/line>\n              <line x1=\"70\" y1=\"390\" x2=\"70\" y2=\"50\" stroke=\"#111827\" stroke-width=\"2\"><\/line>\n              <polygon points=\"620,390 610,384 610,396\" fill=\"#111827\"><\/polygon>\n              <polygon points=\"70,50 64,60 76,60\" fill=\"#111827\"><\/polygon>\n\n              <text x=\"345\" y=\"435\" text-anchor=\"middle\" fill=\"#111827\" font-size=\"18\" font-weight=\"700\">Mass of CaCO<tspan baseline-shift=\"sub\" font-size=\"12\">3<\/tspan> \/ g<\/text>\n              <text x=\"22\" y=\"225\" text-anchor=\"middle\" fill=\"#111827\" font-size=\"18\" font-weight=\"700\" transform=\"rotate(-90 22 225)\">Volume of CO<tspan baseline-shift=\"sub\" font-size=\"12\">2<\/tspan> \/ cm<tspan baseline-shift=\"super\" font-size=\"12\">3<\/tspan><\/text>\n\n              <g id=\"olsCp1AxisLabels\"><\/g>\n              <g id=\"olsCp1LineLayer\"><\/g>\n              <g id=\"olsCp1GuideLayer\"><\/g>\n              <g id=\"olsCp1PointLayer\"><\/g>\n            <\/svg>\n\n            <div id=\"olsCp1Feedback\" class=\"ols-widget-feedback\">Start by plotting the experimental points from the results table.<\/div>\n          <\/div>\n        <\/div>\n      <\/section>\n\n      <article class=\"ols-note-card purple\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">6<\/div>\n          <h2>Calculating the Molar Volume<\/h2>\n        <\/div>\n\n        <p>After plotting the graph, read the volume of carbon dioxide produced from <strong>0.25 g of CaCO<sub>3<\/sub><\/strong>. The sample graph gives about <strong>60 cm<sup>3<\/sup><\/strong> of CO<sub>2<\/sub>.<\/p>\n\n        <div class=\"ols-equation-box\">\n          moles of CaCO<sub>3<\/sub> = mass \u00f7 molar mass<br>\n          moles of CaCO<sub>3<\/sub> = 0.25 \u00f7 100.1 = 0.00250 mol\n        <\/div>\n\n        <p>The balanced equation shows a <strong>1:1 mole ratio<\/strong> between CaCO<sub>3<\/sub> and CO<sub>2<\/sub>, so:<\/p>\n\n        <div class=\"ols-equation-box\">\n          moles of CO<sub>2<\/sub> = 0.00250 mol\n        <\/div>\n\n        <div class=\"ols-equation-box\">\n          molar volume = volume \u00f7 moles<br>\n          molar volume = 60 \u00f7 0.00250 = 24 000 cm<sup>3<\/sup> mol<sup>-1<\/sup><br>\n          24 000 cm<sup>3<\/sup> mol<sup>-1<\/sup> = 24 dm<sup>3<\/sup> mol<sup>-1<\/sup>\n        <\/div>\n\n        <div class=\"ols-figure-card\">\n          <a class=\"ols-figure-link ols-lightbox-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/finding-the-molar-volume-of-carbon-dioxide.webp\" aria-label=\"Open molar volume calculation infographic\">\n            <div class=\"ols-figure-image\">\n              <img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/finding-the-molar-volume-of-carbon-dioxide.webp\" alt=\"Infographic showing sample results, graph reading and step-by-step calculation for finding the molar volume of carbon dioxide.\">\n            <\/div>\n          <\/a>\n          <div class=\"ols-figure-caption\">\n            <p>This worked visual connects the data table, graph read-off at 0.25 g and final molar volume calculation.<\/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\">7<\/div>\n          <h2>Checking That Ethanoic Acid Is in Excess<\/h2>\n        <\/div>\n\n        <p>For the experiment to work properly, calcium carbonate should be the limiting reagent. This means the ethanoic acid must be in excess, even when the largest allowed mass of calcium carbonate is used.<\/p>\n\n        <div class=\"ols-equation-box\">\n          maximum mass of CaCO<sub>3<\/sub> = 0.40 g<br>\n          moles of CaCO<sub>3<\/sub> = 0.40 \u00f7 100.1 = 0.003996 mol\n        <\/div>\n\n        <div class=\"ols-equation-box\">\n          moles of ethanoic acid = concentration \u00d7 volume<br>\n          moles of CH<sub>3<\/sub>COOH = 1.00 \u00d7 30 \u00f7 1000 = 0.030 mol\n        <\/div>\n\n        <p>The equation needs <strong>2 moles of ethanoic acid<\/strong> for every <strong>1 mole of calcium carbonate<\/strong>.<\/p>\n\n        <div class=\"ols-equation-box\">\n          acid needed = 2 \u00d7 0.003996 = 0.00799 mol<br>\n          acid available = 0.030 mol\n        <\/div>\n\n        <div class=\"ols-key-box\">\n          <p><strong>Conclusion:<\/strong> 0.030 mol of acid is much greater than 0.00799 mol needed, so ethanoic acid is in excess in all experimental runs.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card orange\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">8<\/div>\n          <h2>Errors, Limitations and Improvements<\/h2>\n        <\/div>\n\n        <p>Practical questions often test whether you can identify the main source of error and explain how it affects the calculated molar volume.<\/p>\n\n        <div class=\"ols-table-wrap\">\n          <table class=\"ols-table\">\n            <thead>\n              <tr>\n                <th>Issue<\/th>\n                <th>Effect on result<\/th>\n                <th>Improvement<\/th>\n              <\/tr>\n            <\/thead>\n            <tbody>\n              <tr>\n                <td>Gas escapes before the bung is replaced.<\/td>\n                <td>Measured CO<sub>2<\/sub> volume is too low, so calculated molar volume is too low.<\/td>\n                <td>Use a sealed mixing arrangement or replace the bung as quickly as possible.<\/td>\n              <\/tr>\n              <tr>\n                <td>Carbon dioxide is slightly soluble in water.<\/td>\n                <td>Some CO<sub>2<\/sub> is not collected, so the gas volume is too low.<\/td>\n                <td>Use a gas syringe instead of collecting the gas over water.<\/td>\n              <\/tr>\n              <tr>\n                <td>Delivery tube becomes blocked.<\/td>\n                <td>Gas cannot pass through safely and pressure can build up.<\/td>\n                <td>Remove the bung, clear the blockage, and repeat the experiment from the start.<\/td>\n              <\/tr>\n              <tr>\n                <td>Small mass has a high percentage uncertainty.<\/td>\n                <td>The calculated amount of CaCO<sub>3<\/sub> is less reliable.<\/td>\n                <td>Use an appropriate balance and avoid relying on very small masses alone.<\/td>\n              <\/tr>\n            <\/tbody>\n          <\/table>\n        <\/div>\n\n        <div class=\"ols-warning-box\">\n          <p><strong>Exam trap:<\/strong> Do not discard the first bubbles of gas. They are air displaced from the delivery tube, and the volume of CO<sub>2<\/sub> left in the delivery tube at the end balances this.<\/p>\n        <\/div>\n      <\/article>\n\n      <article class=\"ols-note-card\">\n        <div class=\"ols-note-title\">\n          <div class=\"ols-note-icon\">9<\/div>\n          <h2>Common Exam Points<\/h2>\n        <\/div>\n\n        <ul>\n          <li>State the correct equation for CaCO<sub>3<\/sub> reacting with CH<sub>3<\/sub>COOH.<\/li>\n          <li>Explain why weighing the test tube before and after is more accurate than assuming all solid is transferred.<\/li>\n          <li>Explain why the straight line should pass through the origin.<\/li>\n          <li>Use the graph to read a gas volume for a chosen mass of CaCO<sub>3<\/sub>.<\/li>\n          <li>Calculate moles of CaCO<sub>3<\/sub> from mass and molar mass.<\/li>\n          <li>Use the 1:1 mole ratio to find moles of CO<sub>2<\/sub>.<\/li>\n          <li>Explain why gas loss or dissolving CO<sub>2<\/sub> makes the calculated molar volume too low.<\/li>\n          <li>Suggest a gas syringe as an improvement when the gas is soluble in water.<\/li>\n        <\/ul>\n      <\/article>\n\n\n      \n\n      \n\n      <section class=\"ols-faq-card\">\n        <h2>Core Practical 1 FAQs<\/h2>\n        <p>These questions focus on the main exam points for measuring molar volume, interpreting the graph and evaluating the practical method.<\/p>\n\n        <div class=\"ols-faq-list\">\n          <div class=\"ols-faq-item\">\n            <h3>Why is the bung replaced quickly?<\/h3>\n            <p>The bung is replaced quickly to reduce the amount of carbon dioxide lost before the gas enters the delivery tube. Gas loss makes the measured volume too low.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why is the line of best fit drawn through the origin?<\/h3>\n            <p>If no calcium carbonate is used, no carbon dioxide should be produced. This means the graph should pass through zero mass and zero gas volume.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why use 0.25 g of calcium carbonate for the calculation?<\/h3>\n            <p>The graph is used to read the volume of carbon dioxide produced by 0.25 g of calcium carbonate. This mass is then converted into moles, allowing molar volume to be calculated.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why can a gas syringe improve the experiment?<\/h3>\n            <p>A gas syringe measures gas directly and avoids the problem of carbon dioxide dissolving in water during collection over water.<\/p>\n          <\/div>\n\n          <div class=\"ols-faq-item\">\n            <h3>Why should the first bubbles not be ignored?<\/h3>\n            <p>The first bubbles are air displaced from the delivery tube. The volume of carbon dioxide left in the delivery tube at the end balances this, so ignoring the first bubbles introduces an error.<\/p>\n          <\/div>\n        <\/div>\n      <\/section>\n      <section class=\"ols-author-footprint\">\n        <p><strong>OLS Author Copyright Footprint:<\/strong> This revision note page was written and structured by <strong>Dr. Mohammed Al-Fatah<\/strong> for Online Learning System. It is designed as a free revision layer for Edexcel International A Level Chemistry students and links to deeper paid-course practice, feedback and progress tracking inside OLS.<\/p>\n      <\/section>\n    <\/main>\n  <\/div>\n\n  <div class=\"ols-lightbox\" id=\"olsCp1Lightbox\" aria-hidden=\"true\">\n    <button type=\"button\" id=\"olsCp1LightboxClose\" aria-label=\"Close fullscreen image\">\u00d7<\/button>\n    <img decoding=\"async\" id=\"olsCp1LightboxImage\" src=\"\" alt=\"\">\n  <\/div>\n\n  <script>\n    (function(){\n      var data = [\n        {x:0.05,y:11},\n        {x:0.11,y:27},\n        {x:0.17,y:32},\n        {x:0.21,y:50},\n        {x:0.24,y:59},\n        {x:0.32,y:74},\n        {x:0.33,y:80}\n      ];\n\n      var svg = document.getElementById(\"olsCp1GraphSvg\");\n      var grid = document.getElementById(\"olsCp1Grid\");\n      var axisLabels = document.getElementById(\"olsCp1AxisLabels\");\n      var points = document.getElementById(\"olsCp1PointLayer\");\n      var lineLayer = document.getElementById(\"olsCp1LineLayer\");\n      var guideLayer = document.getElementById(\"olsCp1GuideLayer\");\n      var feedback = document.getElementById(\"olsCp1Feedback\");\n      var slider = document.getElementById(\"olsCp1MassSlider\");\n      var massValue = document.getElementById(\"olsCp1MassValue\");\n\n      var plotBtn = document.getElementById(\"olsCp1PlotBtn\");\n      var lineBtn = document.getElementById(\"olsCp1LineBtn\");\n      var readBtn = document.getElementById(\"olsCp1ReadBtn\");\n      var calcBtn = document.getElementById(\"olsCp1CalcBtn\");\n      var resetBtn = document.getElementById(\"olsCp1ResetBtn\");\n      var stepButtons = [plotBtn, lineBtn, readBtn, calcBtn];\n      var currentStep = 0;\n\n      function setButtonSequence(activeIndex){\n        currentStep = activeIndex;\n        for (var i = 0; i < stepButtons.length; i++) {\n          var btn = stepButtons[i];\n          if (!btn) continue;\n          btn.classList.remove(\"is-pulsing\", \"is-locked\", \"is-complete\");\n          if (i < activeIndex) {\n            btn.classList.add(\"is-complete\");\n            btn.disabled = false;\n          } else if (i === activeIndex) {\n            btn.classList.add(\"is-pulsing\");\n            btn.disabled = false;\n          } else {\n            btn.classList.add(\"is-locked\");\n            btn.disabled = true;\n          }\n        }\n        if (resetBtn) {\n          resetBtn.classList.add(\"is-reset\");\n          resetBtn.disabled = false;\n        }\n      }\n\n      var left = 70;\n      var right = 620;\n      var top = 50;\n      var bottom = 390;\n      var maxX = 0.35;\n      var maxY = 85;\n      var slope = 240;\n\n      function xToSvg(x){\n        return left + (x \/ maxX) * (right - left);\n      }\n\n      function yToSvg(y){\n        return bottom - (y \/ maxY) * (bottom - top);\n      }\n\n      function makeSvgElement(name){\n        return document.createElementNS(\"http:\/\/www.w3.org\/2000\/svg\", name);\n      }\n\n      function clearLayer(layer){\n        while (layer.firstChild) {\n          layer.removeChild(layer.firstChild);\n        }\n      }\n\n      function drawGrid(){\n        clearLayer(grid);\n        clearLayer(axisLabels);\n\n        var xTicks = [0,0.05,0.10,0.15,0.20,0.25,0.30,0.35];\n        var yTicks = [0,10,20,30,40,50,60,70,80];\n\n        for (var i = 0; i < xTicks.length; i++) {\n          var x = xToSvg(xTicks[i]);\n\n          var gx = makeSvgElement(\"line\");\n          gx.setAttribute(\"x1\", x);\n          gx.setAttribute(\"y1\", top);\n          gx.setAttribute(\"x2\", x);\n          gx.setAttribute(\"y2\", bottom);\n          gx.setAttribute(\"stroke\", \"#d0d5dd\");\n          gx.setAttribute(\"stroke-width\", \"1\");\n          gx.setAttribute(\"stroke-dasharray\", \"5 5\");\n          grid.appendChild(gx);\n\n          var xt = makeSvgElement(\"text\");\n          xt.setAttribute(\"x\", x);\n          xt.setAttribute(\"y\", \"412\");\n          xt.setAttribute(\"text-anchor\", \"middle\");\n          xt.setAttribute(\"fill\", \"#111827\");\n          xt.setAttribute(\"font-size\", \"13\");\n          xt.textContent = xTicks[i].toFixed(2);\n          axisLabels.appendChild(xt);\n        }\n\n        for (var j = 0; j < yTicks.length; j++) {\n          var y = yToSvg(yTicks[j]);\n\n          var gy = makeSvgElement(\"line\");\n          gy.setAttribute(\"x1\", left);\n          gy.setAttribute(\"y1\", y);\n          gy.setAttribute(\"x2\", right);\n          gy.setAttribute(\"y2\", y);\n          gy.setAttribute(\"stroke\", \"#d0d5dd\");\n          gy.setAttribute(\"stroke-width\", \"1\");\n          gy.setAttribute(\"stroke-dasharray\", \"5 5\");\n          grid.appendChild(gy);\n\n          var yt = makeSvgElement(\"text\");\n          yt.setAttribute(\"x\", \"58\");\n          yt.setAttribute(\"y\", y + 5);\n          yt.setAttribute(\"text-anchor\", \"end\");\n          yt.setAttribute(\"fill\", \"#111827\");\n          yt.setAttribute(\"font-size\", \"13\");\n          yt.textContent = String(yTicks[j]);\n          axisLabels.appendChild(yt);\n        }\n      }\n\n      function plotPoints(){\n        clearLayer(points);\n\n        for (var i = 0; i < data.length; i++) {\n          var c = makeSvgElement(\"circle\");\n          c.setAttribute(\"cx\", xToSvg(data[i].x));\n          c.setAttribute(\"cy\", yToSvg(data[i].y));\n          c.setAttribute(\"r\", \"6\");\n          c.setAttribute(\"fill\", \"#0b4eb3\");\n          c.setAttribute(\"stroke\", \"#ffffff\");\n          c.setAttribute(\"stroke-width\", \"2\");\n          points.appendChild(c);\n        }\n\n        feedback.innerHTML = \"<strong>Step 1 complete:<\/strong> The experimental points have been plotted. Notice that they are close to a straight-line trend, but not perfectly exact.\";\n        setButtonSequence(1);\n      }\n\n      function drawBestFitLine(){\n        clearLayer(lineLayer);\n\n        var line = makeSvgElement(\"line\");\n        line.setAttribute(\"x1\", xToSvg(0));\n        line.setAttribute(\"y1\", yToSvg(0));\n        line.setAttribute(\"x2\", xToSvg(0.35));\n        line.setAttribute(\"y2\", yToSvg(0.35 * slope));\n        line.setAttribute(\"stroke\", \"#0b4eb3\");\n        line.setAttribute(\"stroke-width\", \"3\");\n        lineLayer.appendChild(line);\n\n        feedback.innerHTML = \"<strong>Step 2 complete:<\/strong> The line has been drawn through the origin because 0 g of CaCO<sub>3<\/sub> should produce 0 cm<sup>3<\/sup> of CO<sub>2<\/sub>.\";\n        setButtonSequence(2);\n      }\n\n      function drawGuide(){\n        clearLayer(guideLayer);\n\n        var selectedMass = Number(slider.value);\n        var volume = selectedMass * slope;\n        var px = xToSvg(selectedMass);\n        var py = yToSvg(volume);\n\n        var vertical = makeSvgElement(\"line\");\n        vertical.setAttribute(\"x1\", px);\n        vertical.setAttribute(\"y1\", bottom);\n        vertical.setAttribute(\"x2\", px);\n        vertical.setAttribute(\"y2\", py);\n        vertical.setAttribute(\"stroke\", \"#168a2d\");\n        vertical.setAttribute(\"stroke-width\", \"2\");\n        vertical.setAttribute(\"stroke-dasharray\", \"4 4\");\n        guideLayer.appendChild(vertical);\n\n        var horizontal = makeSvgElement(\"line\");\n        horizontal.setAttribute(\"x1\", left);\n        horizontal.setAttribute(\"y1\", py);\n        horizontal.setAttribute(\"x2\", px);\n        horizontal.setAttribute(\"y2\", py);\n        horizontal.setAttribute(\"stroke\", \"#168a2d\");\n        horizontal.setAttribute(\"stroke-width\", \"2\");\n        horizontal.setAttribute(\"stroke-dasharray\", \"4 4\");\n        guideLayer.appendChild(horizontal);\n\n        var point = makeSvgElement(\"circle\");\n        point.setAttribute(\"cx\", px);\n        point.setAttribute(\"cy\", py);\n        point.setAttribute(\"r\", \"7\");\n        point.setAttribute(\"fill\", \"#168a2d\");\n        point.setAttribute(\"stroke\", \"#ffffff\");\n        point.setAttribute(\"stroke-width\", \"2\");\n        guideLayer.appendChild(point);\n\n        var labelBox = makeSvgElement(\"rect\");\n        labelBox.setAttribute(\"x\", px + 15);\n        labelBox.setAttribute(\"y\", py - 46);\n        labelBox.setAttribute(\"width\", \"142\");\n        labelBox.setAttribute(\"height\", \"52\");\n        labelBox.setAttribute(\"rx\", \"12\");\n        labelBox.setAttribute(\"fill\", \"#f0f7f1\");\n        labelBox.setAttribute(\"stroke\", \"#168a2d\");\n        labelBox.setAttribute(\"stroke-width\", \"1.5\");\n        guideLayer.appendChild(labelBox);\n\n        var label = makeSvgElement(\"text\");\n        label.setAttribute(\"x\", px + 26);\n        label.setAttribute(\"y\", py - 24);\n        label.setAttribute(\"fill\", \"#168a2d\");\n        label.setAttribute(\"font-size\", \"14\");\n        label.setAttribute(\"font-weight\", \"700\");\n        label.textContent = selectedMass.toFixed(2) + \" g gives\";\n        guideLayer.appendChild(label);\n\n        var label2 = makeSvgElement(\"text\");\n        label2.setAttribute(\"x\", px + 26);\n        label2.setAttribute(\"y\", py - 6);\n        label2.setAttribute(\"fill\", \"#168a2d\");\n        label2.setAttribute(\"font-size\", \"14\");\n        label2.setAttribute(\"font-weight\", \"700\");\n        label2.textContent = volume.toFixed(0) + \" cm3 CO2\";\n        guideLayer.appendChild(label2);\n\n        feedback.innerHTML = \"<strong>Step 3 complete:<\/strong> At \" + selectedMass.toFixed(2) + \" g of CaCO<sub>3<\/sub>, the graph gives about \" + volume.toFixed(0) + \" cm<sup>3<\/sup> of CO<sub>2<\/sub>.\";\n        setButtonSequence(3);\n      }\n\n      function showCalculation(){\n        var selectedMass = Number(slider.value);\n        var volume = selectedMass * slope;\n        var moles = selectedMass \/ 100.1;\n        var molarVolumeCm3 = volume \/ moles;\n        var molarVolumeDm3 = molarVolumeCm3 \/ 1000;\n\n        feedback.innerHTML = \"<strong>Calculation:<\/strong> moles of CaCO<sub>3<\/sub> = \" + selectedMass.toFixed(2) + \" \u00f7 100.1 = \" + moles.toPrecision(3) + \" mol. The mole ratio is 1:1, so moles of CO<sub>2<\/sub> = \" + moles.toPrecision(3) + \" mol. Molar volume = \" + volume.toFixed(0) + \" \u00f7 \" + moles.toPrecision(3) + \" = \" + molarVolumeCm3.toPrecision(3) + \" cm<sup>3<\/sup> mol<sup>-1<\/sup>, which is about \" + molarVolumeDm3.toFixed(1) + \" dm<sup>3<\/sup> mol<sup>-1<\/sup>.\";\n        setButtonSequence(4);\n      }\n\n      function resetGraph(){\n        clearLayer(points);\n        clearLayer(lineLayer);\n        clearLayer(guideLayer);\n        slider.value = \"0.25\";\n        massValue.textContent = \"0.25\";\n        feedback.textContent = \"Start by plotting the experimental points from the results table.\";\n        setButtonSequence(0);\n      }\n\n      if (slider) {\n        slider.addEventListener(\"input\", function(){\n          massValue.textContent = Number(slider.value).toFixed(2);\n          if (guideLayer) {\n            if (guideLayer.childNodes.length > 0) {\n              drawGuide();\n            }\n          }\n        });\n      }\n\n      if (plotBtn) {\n        plotBtn.addEventListener(\"click\", plotPoints);\n      }\n\n      if (lineBtn) {\n        lineBtn.addEventListener(\"click\", drawBestFitLine);\n      }\n\n      if (readBtn) {\n        readBtn.addEventListener(\"click\", drawGuide);\n      }\n\n      if (calcBtn) {\n        calcBtn.addEventListener(\"click\", showCalculation);\n      }\n\n      if (resetBtn) {\n        resetBtn.addEventListener(\"click\", resetGraph);\n      }\n\n      drawGrid();\n      setButtonSequence(0);\n\n      var lightbox = document.getElementById(\"olsCp1Lightbox\");\n      var lightboxImage = document.getElementById(\"olsCp1LightboxImage\");\n      var lightboxClose = document.getElementById(\"olsCp1LightboxClose\");\n      var links = document.querySelectorAll(\".ols-cp1-molar-volume-page .ols-lightbox-link\");\n\n      function openLightbox(src, altText){\n        if (lightbox) {\n          if (lightboxImage) {\n            lightboxImage.setAttribute(\"src\", src);\n            lightboxImage.setAttribute(\"alt\", altText);\n          }\n          lightbox.classList.add(\"is-open\");\n          lightbox.setAttribute(\"aria-hidden\", \"false\");\n        }\n      }\n\n      function closeLightbox(){\n        if (lightbox) {\n          lightbox.classList.remove(\"is-open\");\n          lightbox.setAttribute(\"aria-hidden\", \"true\");\n          if (lightboxImage) {\n            lightboxImage.setAttribute(\"src\", \"\");\n            lightboxImage.setAttribute(\"alt\", \"\");\n          }\n        }\n      }\n\n      for (var i = 0; i < links.length; i++) {\n        links[i].addEventListener(\"click\", function(event){\n          var image = this.querySelector(\"img\");\n          if (image) {\n            event.preventDefault();\n            openLightbox(image.getAttribute(\"src\"), image.getAttribute(\"alt\"));\n          }\n        });\n      }\n\n      if (lightboxClose) {\n        lightboxClose.addEventListener(\"click\", closeLightbox);\n      }\n\n      if (lightbox) {\n        lightbox.addEventListener(\"click\", function(event){\n          if (event.target === lightbox) {\n            closeLightbox();\n          }\n        });\n      }\n\n      document.addEventListener(\"keydown\", function(event){\n        if (event.key === \"Escape\") {\n          closeLightbox();\n        }\n      });\n    })();\n  <\/script>\n\n  <script type=\"application\/ld+json\">\n  {\n    \"@context\": \"https:\/\/schema.org\",\n    \"@graph\": [\n      {\n        \"@type\": \"WebPage\",\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#webpage\",\n        \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/\",\n        \"name\": \"Core Practical 1: Molar Volume of a Gas\",\n        \"headline\": \"Core Practical 1: Molar Volume of a Gas\",\n        \"description\": \"Edexcel International AS Chemistry revision notes for Core Practical 1, measuring the molar volume of carbon dioxide using calcium carbonate, ethanoic acid, gas collection over water, graphing and mole calculations.\",\n        \"inLanguage\": \"en-GB\",\n        \"author\": {\n          \"@type\": \"Person\",\n          \"name\": \"Dr. Mohammed Al-Fatah\"\n        },\n        \"publisher\": {\n          \"@type\": \"Organization\",\n          \"name\": \"Online Learning System\",\n          \"url\": \"https:\/\/www.onlinelearningsystem.net\/\"\n        },\n        \"breadcrumb\": {\n          \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#breadcrumb\"\n        },\n        \"primaryImageOfPage\": {\n          \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#image\"\n        }\n      },\n      {\n        \"@type\": \"BreadcrumbList\",\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#breadcrumb\",\n        \"itemListElement\": [\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 1,\n            \"item\": {\n              \"@type\": \"WebPage\",\n              \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\",\n              \"name\": \"Revision Notes\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 2,\n            \"item\": {\n              \"@type\": \"WebPage\",\n              \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\",\n              \"name\": \"A Level Chemistry\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 3,\n            \"item\": {\n              \"@type\": \"WebPage\",\n              \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/\",\n              \"name\": \"Edexcel International\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 4,\n            \"item\": {\n              \"@type\": \"WebPage\",\n              \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/\",\n              \"name\": \"CP1 Molar Volume of a Gas\"\n            }\n          }\n        ]\n      },\n      {\n        \"@type\": \"Course\",\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#course\",\n        \"name\": \"Core Practical 1: Molar Volume of a Gas\",\n        \"description\": \"Revision notes for Edexcel International AS Chemistry covering Core Practical 1, measuring the molar volume of carbon dioxide using gas collection over water, graphing and mole calculations.\",\n        \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/\",\n        \"provider\": {\n          \"@type\": \"Organization\",\n          \"name\": \"Online Learning System\",\n          \"url\": \"https:\/\/www.onlinelearningsystem.net\/\"\n        },\n        \"educationalLevel\": \"AS \/ A Level\",\n        \"inLanguage\": \"en-GB\",\n        \"about\": [\n          \"Molar volume of a gas\",\n          \"Carbon dioxide\",\n          \"Calcium carbonate\",\n          \"Ethanoic acid\",\n          \"Gas collection over water\",\n          \"Practical skills\",\n          \"Edexcel International Chemistry\"\n        ],\n        \"teaches\": [\n          \"Describe how carbon dioxide is collected over water\",\n          \"Explain how to calculate moles of calcium carbonate\",\n          \"Use a graph to estimate carbon dioxide volume\",\n          \"Calculate molar volume from experimental data\",\n          \"Evaluate errors and improvements in gas collection\"\n        ],\n        \"hasCourseInstance\": {\n          \"@type\": \"CourseInstance\",\n          \"courseMode\": \"Online\"\n        }\n      },\n      {\n        \"@type\": \"ImageObject\",\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#image\",\n        \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/finding-the-molar-volume-of-carbon-dioxide.webp\",\n        \"contentUrl\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/06\/finding-the-molar-volume-of-carbon-dioxide.webp\",\n        \"name\": \"Finding the Molar Volume of Carbon Dioxide\",\n        \"caption\": \"Visual summary showing how sample data and graph reading are used to calculate the molar volume of carbon dioxide.\",\n        \"description\": \"Infographic for Edexcel International AS Chemistry Core Practical 1 showing sample data, graph reading at 0.25 g calcium carbonate and the molar volume calculation for carbon dioxide.\"\n      },\n      {\n        \"@type\": \"ItemList\",\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#corepracticals\",\n        \"name\": \"Edexcel International Chemistry Core Practicals\",\n        \"itemListElement\": [\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 1,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP1: Molar Volume of a Gas\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/\",\n              \"description\": \"Core practical revision notes for measuring the molar volume of carbon dioxide.\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 2,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP2: Enthalpy Change via Hess Law\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-2-enthalpy-change-via-hess-law\/\",\n              \"description\": \"Core practical revision notes for determining enthalpy change using Hess law.\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 3,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP3: Concentration of HCl by Titration\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-3-concentration-of-hcl-by-titration\/\",\n              \"description\": \"Core practical revision notes for finding the concentration of hydrochloric acid by titration.\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 4,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP4: Preparation of a Standard Solution\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-4-preparation-of-a-standard-solution\/\",\n              \"description\": \"Core practical revision notes for preparing a standard solution.\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 5,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP5: Hydrolysis of Halogenoalkanes\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-5-hydrolysis-of-halogenoalkanes\/\",\n              \"description\": \"Core practical revision notes for investigating hydrolysis of halogenoalkanes.\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 6,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP6: Chlorination of 2-methylpropan-2-ol\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-6-chlorination-of-2-methylpropan-2-ol\/\",\n              \"description\": \"Core practical revision notes for chlorination of 2-methylpropan-2-ol.\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 7,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP7: Oxidation of Propan-1-ol\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-7-oxidation-of-propan-1-ol\/\",\n              \"description\": \"Core practical revision notes for oxidation of propan-1-ol.\"\n            }\n          },\n          {\n            \"@type\": \"ListItem\",\n            \"position\": 8,\n            \"item\": {\n              \"@type\": \"Course\",\n              \"name\": \"CP8: Analysis of Inorganic and Organic Unknowns\",\n              \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-8-analysis-of-inorganic-and-organic-unknowns\/\",\n              \"description\": \"Core practical revision notes for analysis of inorganic and organic unknowns.\"\n            }\n          }\n        ]\n      },\n      {\n        \"@type\": \"FAQPage\",\n        \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/cp-1-molar-volume-of-a-gas\/#faq\",\n        \"mainEntity\": [\n          {\n            \"@type\": \"Question\",\n            \"name\": \"Why is the bung replaced quickly in Core Practical 1?\",\n            \"acceptedAnswer\": {\n              \"@type\": \"Answer\",\n              \"text\": \"The bung is replaced quickly to reduce the amount of carbon dioxide lost before the gas enters the delivery tube. Gas loss makes the measured gas volume too low.\"\n            }\n          },\n          {\n            \"@type\": \"Question\",\n            \"name\": \"Why is the graph drawn through the origin?\",\n            \"acceptedAnswer\": {\n              \"@type\": \"Answer\",\n              \"text\": \"The graph is drawn through the origin because zero calcium carbonate should produce zero carbon dioxide.\"\n            }\n          },\n          {\n            \"@type\": \"Question\",\n            \"name\": \"How is molar volume calculated in this practical?\",\n            \"acceptedAnswer\": {\n              \"@type\": \"Answer\",\n              \"text\": \"The volume of carbon dioxide is read from the graph for 0.25 g of calcium carbonate. The mass is converted to moles, the 1:1 mole ratio gives the moles of carbon dioxide, and molar volume is found by dividing gas volume by moles of gas.\"\n            }\n          },\n          {\n            \"@type\": \"Question\",\n            \"name\": \"Why can using a gas syringe improve the experiment?\",\n            \"acceptedAnswer\": {\n              \"@type\": \"Answer\",\n              \"text\": \"A gas syringe can improve the experiment because it measures the gas directly and avoids carbon dioxide dissolving in water during gas collection over water.\"\n            }\n          }\n        ]\n      }\n    ]\n  }\n  <\/script>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Revision Notes \/ A Level Chemistry \/ Edexcel International \/ CP1 Molar Volume of a Gas Core Practical 1: Molar Volume of a Gas A guided Edexcel International AS Chemistry revision walkthrough for measuring the molar volume of carbon dioxide using calcium carbonate, ethanoic acid, gas collection over water, graphing and mole calculations. Exam board: [&hellip;]<\/p>\n","protected":false},"author":12,"featured_media":0,"parent":5028,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-4956","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4956","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=4956"}],"version-history":[{"count":0,"href":"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-json\/wp\/v2\/pages\/4956\/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=4956"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}