{"id":8049,"date":"2026-09-15T08:23:31","date_gmt":"2026-09-15T07:23:31","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/"},"modified":"2026-09-15T08:35:19","modified_gmt":"2026-09-15T07:35:19","slug":"2-1-3-amount-of-substance","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/","title":{"rendered":"2.1.3 Amount of Substance"},"content":{"rendered":"\n<div class=\"ols-ocr213-page\">\n\n  <aside class=\"ols-sidebar\">\n  <div class=\"ols-sidebar-header\">\n    <h3>Revision Notes<\/h3>\n    <p>OCR A Level Chemistry A<\/p>\n  <\/div>\n  <div class=\"ols-topic-group\">\n    <h4>2.1.3 Amount of Substance<\/h4>\n    <ul class=\"ols-topic-list\">\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/\">Section overview<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/atoms-elements-and-molecules\/\">Atoms, Elements and Molecules<\/a><\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/mole-calculations\/\">Mole Calculations<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/mole-calculations\/comparing-masses-of-substances\/\">Comparing Masses of Substances<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/mole-calculations\/calculations-involving-moles\/\">Calculations involving Moles<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/mole-calculations\/calculations-using-reacting-masses\/\">Calculations using Reacting Masses<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/mole-calculations\/the-yield-of-a-reaction\/\">The Yield of a Reaction<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/mole-calculations\/atom-economy\/\">Atom Economy<\/a><\/li>\n        <\/ul>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/empirical-and-molecular-formulae\/\">Empirical and Molecular Formulae<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/empirical-and-molecular-formulae\/empirical-formulae\/\">Empirical Formulae<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/empirical-and-molecular-formulae\/molecular-formulae\/\">Molecular Formulae<\/a><\/li>\n        <\/ul>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/calculations-with-solutions-and-gases\/\">Calculations with Solutions and Gases<\/a>\n        <ul class=\"ols-subtopic-list\">\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/calculations-with-solutions-and-gases\/molar-volume-calculations\/\">Molar Volume Calculations<\/a><\/li>\n          <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/calculations-with-solutions-and-gases\/concentrations-of-solutions\/\">Concentrations of Solutions<\/a><\/li>\n<li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/hydrated-salts-and-water-of-crystallisation\/\">Hydrated Salts and Water of Crystallisation<\/a><\/li>\n<li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/measuring-mass-volume-and-gas-volume\/\">Measuring Mass, Volume and Gas Volume<\/a><\/li>\n        <\/ul>\n      <\/li>\n    <\/ul>\n  <\/div>\n  <div class=\"ols-topic-group\">\n    <h4>Other OCR Sections<\/h4>\n    <ul class=\"ols-topic-list\">\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-1-atomic-structure-and-isotopes\/\">2.1.1 Atomic Structure and Isotopes<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-2-compounds-formulae-and-equations\/\">2.1.2 Compounds, Formulae and Equations<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-4-acids\/\">2.1.4 Acids<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-1-electron-structure\/\">2.2.1 Electron Structure<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-2-2-bonding-and-structure\/\">2.2.2 Bonding and Structure<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/3-1-1-periodicity\/\">3.1.1 Periodicity<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-1-basic-concepts-of-organic-chemistry\/\">4.1.1 Basic Concepts of Organic Chemistry<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-2-alkanes\/\">4.1.2 Alkanes<\/a><\/li>\n      <li><a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/4-1-3-alkenes\/\">4.1.3 Alkenes<\/a><\/li>\n    <\/ul>\n  <\/div>\n<\/aside>\n<script>\r\n(function() {\r\n  function normalisePath(path) {\r\n    return String(path || '')\r\n      .split('?')[0]\r\n      .split('#')[0]\r\n      .replace(\/\\\/+$\/, '')\r\n      .toLowerCase();\r\n  }\r\n\r\n  function highlightActive() {\r\n    var sidebar = document.querySelector('.ols-sidebar');\r\n    if (!sidebar) return false;\r\n\r\n    var currentPath = normalisePath(window.location.pathname);\r\n    var links = 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(max-width: 640px) {\n      .ols-ocr213-intro { padding: 24px 0 52px; }\n      .ols-ocr213-topics { padding: 52px 0 58px; }\n      .ols-ocr213-cards-grid { grid-template-columns: 1fr; gap: 14px; }\n      .ols-ocr213-spec-section { padding: 52px 0 64px; }\n      .ols-ocr213-spec-wrap { padding: 24px 18px; border-radius: 20px; }\n      .ols-ocr213-info-grid { grid-template-columns: 1fr 1fr; }\n      .ols-ocr213-spec-row { flex-direction: column; }\n      .ols-ocr213-spec-code { flex: 0 0 auto; min-height: 34px; }\n    }\n  <\/style>\n\n  <!-- BREADCRUMB BAR -->\n  <div class=\"ols-ocr213-breadcrumb-bar\">\n    <div class=\"ols-ocr213-container\">\n      <nav class=\"ols-ocr213-breadcrumb\" aria-label=\"Breadcrumb\">\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\">Revision Notes<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\">A Level Chemistry<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/\">OCR<\/a> \/\n        <span>2.1.3 Amount of Substance<\/span>\n      <\/nav>\n    <\/div>\n  <\/div>\n\n  <!-- INTRO -->\n  <section class=\"ols-ocr213-intro\">\n    <div class=\"ols-ocr213-container\">\n      <div class=\"ols-ocr213-intro-inner\">\n        <div>\n          <div class=\"ols-ocr213-eyebrow\">OCR A Level Chemistry A &#8211; Module 2 Foundations in Chemistry<\/div>\n          <h1>2.1.3<br>Amount of Substance<\/h1>\n          <div class=\"ols-ocr213-accent-bar\"><\/div>\n          <p class=\"ols-ocr213-intro-lead\">Section 2.1.3 covers the mole and the Avogadro constant, molar mass and molar gas volume, empirical and molecular formulae, hydrated salts, calculations with masses, gas volumes and solutions, the ideal gas equation, percentage yield and atom economy. These pages cover the mole, formulae and every calculation type; hydrated salts and measuring techniques follow with the supplementary set.<\/p>\n        <\/div>\n        <div class=\"ols-ocr213-info-grid\">\n          <div class=\"ols-ocr213-info-card\"><div class=\"ols-ocr213-info-card-label\">Exam Paper<\/div><div class=\"ols-ocr213-info-card-value\">Paper 1 &amp; 2<\/div><div class=\"ols-ocr213-info-card-sub\">H432\/01 and H432\/02<\/div><\/div>\n          <div class=\"ols-ocr213-info-card\"><div class=\"ols-ocr213-info-card-label\">Specification Points<\/div><div class=\"ols-ocr213-info-card-value\">2.1.3 (a) &#8211; (j)<\/div><div class=\"ols-ocr213-info-card-sub\">10 learning outcomes<\/div><\/div>\n          <div class=\"ols-ocr213-info-card\"><div class=\"ols-ocr213-info-card-label\">Topic Parts<\/div><div class=\"ols-ocr213-info-card-value\">4 of 4 live<\/div><div class=\"ols-ocr213-info-card-sub\">Atoms, Mole Calculations, Formulae, Solutions and Gases<\/div><\/div>\n          <div class=\"ols-ocr213-info-card\"><div class=\"ols-ocr213-info-card-label\">Exam Board<\/div><div class=\"ols-ocr213-info-card-value\">OCR A<\/div><div class=\"ols-ocr213-info-card-sub\">H432 (2015 onwards)<\/div><\/div>\n        <\/div>\n      <\/div>\n    <\/div>\n  <\/section>\n\n  <!-- TOPIC CARDS -->\n  <section class=\"ols-ocr213-topics\">\n    <div class=\"ols-ocr213-container\">\n      <div class=\"ols-ocr213-section-header\">\n        <h2 class=\"ols-ocr213-section-title\">Revision Notes<\/h2>\n        <p class=\"ols-ocr213-section-sub\">Work through 2.1.3 in a structured sequence.<\/p>\n      <\/div>\n      <div class=\"ols-ocr213-cards-grid\">\n        <!-- Card 1: Atoms, Elements and Molecules -->\n        <a class=\"ols-ocr213-card ols-ocr213-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/atoms-elements-and-molecules\/\">\n          <div class=\"ols-ocr213-card-img-wrap\">\n            <div class=\"ols-ocr213-visual ols-ocr213-visual--ionic\">\n              <div class=\"ols-ocr213-visual-panel\">\n                <div class=\"ols-ocr213-visual-kicker\">Foundations<\/div>\n                <div class=\"ols-ocr213-visual-main\">Atoms, Elements<br>and Molecules<\/div>\n                <div class=\"ols-ocr213-config-line\" aria-hidden=\"true\"><span>M\u1d63  L = 6.02\u00d710\u00b2\u00b3<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-ocr213-card-num\">1<\/div>\n          <\/div>\n          <div class=\"ols-ocr213-card-body\">\n            <p class=\"ols-ocr213-card-title\">Atoms, Elements and Molecules<\/p>\n            <p class=\"ols-ocr213-card-desc\">Atoms, elements, ions and molecules, relative masses, molar mass, the mole and the Avogadro constant (2.1.3 (a)).<\/p>\n            <span class=\"ols-ocr213-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n        <!-- Card 2: Mole Calculations -->\n        <a class=\"ols-ocr213-card ols-ocr213-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/mole-calculations\/\">\n          <div class=\"ols-ocr213-card-img-wrap\">\n            <div class=\"ols-ocr213-visual ols-ocr213-visual--metallic\">\n              <div class=\"ols-ocr213-visual-panel\">\n                <div class=\"ols-ocr213-visual-kicker\">Calculations<\/div>\n                <div class=\"ols-ocr213-visual-main\">Mole<br>Calculations<\/div>\n                <div class=\"ols-ocr213-config-line\" aria-hidden=\"true\"><span>n = m \/ M<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-ocr213-card-num\">2<\/div>\n          <\/div>\n          <div class=\"ols-ocr213-card-body\">\n            <p class=\"ols-ocr213-card-title\">Mole Calculations<\/p>\n            <p class=\"ols-ocr213-card-desc\">Comparing masses, calculations involving moles, reacting masses, percentage yield and atom economy (2.1.3 (e), (g), (h), (j)).<\/p>\n            <span class=\"ols-ocr213-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n        <!-- Card 3: Empirical and Molecular Formulae -->\n        <a class=\"ols-ocr213-card ols-ocr213-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/empirical-and-molecular-formulae\/\">\n          <div class=\"ols-ocr213-card-img-wrap\">\n            <div class=\"ols-ocr213-visual ols-ocr213-visual--shapes\">\n              <div class=\"ols-ocr213-visual-panel\">\n                <div class=\"ols-ocr213-visual-kicker\">Formulae<\/div>\n                <div class=\"ols-ocr213-visual-main\">Empirical and<br>Molecular<\/div>\n                <div class=\"ols-ocr213-config-line\" aria-hidden=\"true\"><span>CH\u2082O \u2192 C\u2086H\u2081\u2082O\u2086<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-ocr213-card-num\">3<\/div>\n          <\/div>\n          <div class=\"ols-ocr213-card-body\">\n            <p class=\"ols-ocr213-card-title\">Empirical and Molecular Formulae<\/p>\n            <p class=\"ols-ocr213-card-desc\">Empirical formulae from composition by mass and molecular formulae from M\u1d63 (2.1.3 (b), (c)).<\/p>\n            <span class=\"ols-ocr213-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n        <!-- Card 4: Calculations with Solutions and Gases -->\n        <a class=\"ols-ocr213-card ols-ocr213-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/calculations-with-solutions-and-gases\/\">\n          <div class=\"ols-ocr213-card-img-wrap\">\n            <div class=\"ols-ocr213-visual ols-ocr213-visual--forces\">\n              <div class=\"ols-ocr213-visual-panel\">\n                <div class=\"ols-ocr213-visual-kicker\">Gases and solutions<\/div>\n                <div class=\"ols-ocr213-visual-main\">Solutions<br>and Gases<\/div>\n                <div class=\"ols-ocr213-config-line\" aria-hidden=\"true\"><span>pV = nRT<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-ocr213-card-num\">4<\/div>\n          <\/div>\n          <div class=\"ols-ocr213-card-body\">\n            <p class=\"ols-ocr213-card-title\">Calculations with Solutions and Gases<\/p>\n            <p class=\"ols-ocr213-card-desc\">Molar gas volume, the ideal gas equation and concentrations of solutions (2.1.3 (a)(v), (e), (f)).<\/p>\n            <span class=\"ols-ocr213-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n        <a class=\"ols-ocr213-card ols-ocr213-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/hydrated-salts-and-water-of-crystallisation\/\">\n          <div class=\"ols-ocr213-card-img-wrap\">\n            <div class=\"ols-ocr213-visual ols-ocr213-visual--forces\">\n              <div class=\"ols-ocr213-visual-panel\">\n                <div class=\"ols-ocr213-visual-kicker\">Water of crystallisation<\/div>\n                <div class=\"ols-ocr213-visual-main\">Hydrated<br>Salts<\/div>\n                <div class=\"ols-ocr213-config-line\" aria-hidden=\"true\"><span>CuSO\u2084\u00b75H\u2082O<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-ocr213-card-num\">5<\/div>\n          <\/div>\n          <div class=\"ols-ocr213-card-body\">\n            <p class=\"ols-ocr213-card-title\">Hydrated Salts and Water of Crystallisation<\/p>\n            <p class=\"ols-ocr213-card-desc\">Anhydrous and hydrated salts, and finding x in a hydrated salt from percentage composition or heating to constant mass (2.1.3 (d)).<\/p>\n            <span class=\"ols-ocr213-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n\n        <a class=\"ols-ocr213-card ols-ocr213-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/measuring-mass-volume-and-gas-volume\/\">\n          <div class=\"ols-ocr213-card-img-wrap\">\n            <div class=\"ols-ocr213-visual ols-ocr213-visual--forces\">\n              <div class=\"ols-ocr213-visual-panel\">\n                <div class=\"ols-ocr213-visual-kicker\">Apparatus<\/div>\n                <div class=\"ols-ocr213-visual-main\">Measuring<br>Techniques<\/div>\n                <div class=\"ols-ocr213-config-line\" aria-hidden=\"true\"><span>\u00b1 0.05 cm\u00b3<\/span><\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-ocr213-card-num\">6<\/div>\n          <\/div>\n          <div class=\"ols-ocr213-card-body\">\n            <p class=\"ols-ocr213-card-title\">Measuring Mass, Volume and Gas Volume<\/p>\n            <p class=\"ols-ocr213-card-desc\">Weighing by difference, pipettes, burettes and volumetric flasks, collecting gases, and percentage uncertainty (2.1.3 (i)).<\/p>\n            <span class=\"ols-ocr213-card-cta\">Start revising<svg viewBox=\"0 0 16 16\" fill=\"none\" stroke=\"currentColor\" stroke-width=\"2\" stroke-linecap=\"round\" stroke-linejoin=\"round\"><path d=\"M3 8h10M9 4l4 4-4 4\"><\/path><\/svg><\/span>\n          <\/div>\n        <\/a>\n      <\/div>\n    <\/div>\n  <\/section>\n  <!-- SPECIFICATION -->\n  <section class=\"ols-ocr213-spec-section\">\n    <div class=\"ols-ocr213-container\">\n      <div class=\"ols-ocr213-spec-wrap\">\n        <div class=\"ols-ocr213-spec-pill\">Specification Coverage<\/div>\n        <h2 class=\"ols-ocr213-spec-heading\">2.1.3 Amount of Substance &#8211; OCR A Level Chemistry A<\/h2>\n        <p class=\"ols-ocr213-spec-intro-text\">The following OCR A learning outcomes state what candidates should be able to do. Wording is taken from the OCR A Level Chemistry A (H432) specification.<\/p>\n        <h3 class=\"ols-ocr213-spec-group-title\">2.1.3 Amount of Substance<\/h3>\n        <div class=\"ols-ocr213-spec-rows\">\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--light\">\n<div class=\"ols-ocr213-spec-code\">2.1.3(a)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Amount of substance and the mole<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">i<\/div><div class=\"ols-ocr213-spec-sub-text\">explanation and use of the term amount of substance<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">ii<\/div><div class=\"ols-ocr213-spec-sub-text\">explanation and use of the term mole (symbol &#8216;mol&#8217;), as the unit for amount of substance<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">iii<\/div><div class=\"ols-ocr213-spec-sub-text\">explanation and use of the term the Avogadro constant, NA (the number of particles per mole, 6.02 \u00d7 10^23 mol\u20131)<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">iv<\/div><div class=\"ols-ocr213-spec-sub-text\">explanation and use of the term molar mass (mass per mole, units g mol\u20131)<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">v<\/div><div class=\"ols-ocr213-spec-sub-text\">explanation and use of the term molar gas volume (gas volume per mole, units dm3 mol\u20131)<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--mid\">\n<div class=\"ols-ocr213-spec-code ols-ocr213-spec-code--mid\">2.1.3(b)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Empirical and molecular formula<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">i<\/div><div class=\"ols-ocr213-spec-sub-text\">use of the term empirical formula (the simplest whole number ratio of atoms of each element present in a compound)<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">ii<\/div><div class=\"ols-ocr213-spec-sub-text\">use of the term molecular formula (the number and type of atoms of each element in a molecule)<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--light\">\n<div class=\"ols-ocr213-spec-code\">2.1.3(c)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Calculating formulae<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">i<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations of empirical formulae from composition by mass<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">ii<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations of empirical formulae from percentage compositions by mass<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">iii<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations of molecular formulae from composition by mass or percentage compositions by mass and relative molecular mass<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--mid\">\n<div class=\"ols-ocr213-spec-code ols-ocr213-spec-code--mid\">2.1.3(d)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Hydrated salts<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">i<\/div><div class=\"ols-ocr213-spec-sub-text\">the term anhydrous<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">ii<\/div><div class=\"ols-ocr213-spec-sub-text\">the term hydrated<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">iii<\/div><div class=\"ols-ocr213-spec-sub-text\">the term water of crystallisation<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">iv<\/div><div class=\"ols-ocr213-spec-sub-text\">calculation of the formula of a hydrated salt from given percentage composition<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">v<\/div><div class=\"ols-ocr213-spec-sub-text\">calculation of the formula of a hydrated salt from given mass composition<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">vi<\/div><div class=\"ols-ocr213-spec-sub-text\">calculation of the formula of a hydrated salt based on experimental results<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--light\">\n<div class=\"ols-ocr213-spec-code\">2.1.3(e)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Calculations using amount of substance<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">i<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations, using amount of substance in mol, involving mass<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">ii<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations, using amount of substance in mol, involving gas volume<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">iii<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations, using amount of substance in mol, involving solution volume and concentration<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--mid\">\n<div class=\"ols-ocr213-spec-code ols-ocr213-spec-code--mid\">2.1.3(f)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>The ideal gas equation<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\"><\/div><div class=\"ols-ocr213-spec-sub-text\">the ideal gas equation: pV = nRT<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--light\">\n<div class=\"ols-ocr213-spec-code\">2.1.3(g)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Stoichiometric relationships<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\"><\/div><div class=\"ols-ocr213-spec-sub-text\">use of stoichiometric relationships in calculations<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--mid\">\n<div class=\"ols-ocr213-spec-code ols-ocr213-spec-code--mid\">2.1.3(h)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Percentage yield and atom economy<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">i<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations to determine the percentage yield of a reaction or related quantities<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">ii<\/div><div class=\"ols-ocr213-spec-sub-text\">calculations to determine the atom economy of a reaction<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--light\">\n<div class=\"ols-ocr213-spec-code\">2.1.3(i)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Techniques and procedures<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">i<\/div><div class=\"ols-ocr213-spec-sub-text\">the techniques and procedures required during experiments requiring the measurement of mass<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">ii<\/div><div class=\"ols-ocr213-spec-sub-text\">the techniques and procedures required during experiments requiring the measurement of volumes of solutions<\/div><\/div><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\">iii<\/div><div class=\"ols-ocr213-spec-sub-text\">the techniques and procedures required during experiments requiring the measurement of gas volumes<\/div><\/div><\/div><\/div>\n<\/div>\n          <div class=\"ols-ocr213-spec-row ols-ocr213-spec-row--mid\">\n<div class=\"ols-ocr213-spec-code ols-ocr213-spec-code--mid\">2.1.3(j)<\/div>\n<div class=\"ols-ocr213-spec-text\"><strong>Sustainability and atom economy<\/strong><div class=\"ols-ocr213-spec-sub-list\"><div class=\"ols-ocr213-spec-sub-row\"><div class=\"ols-ocr213-spec-sub-code\"><\/div><div class=\"ols-ocr213-spec-sub-text\">the benefits for sustainability of 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mass and molar gas volume, empirical and molecular formulae, hydrated salts, calculations with masses, gas volumes and solutions, 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