{"id":4501,"date":"2026-05-28T05:24:51","date_gmt":"2026-05-28T04:24:51","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/"},"modified":"2026-06-02T08:08:33","modified_gmt":"2026-06-02T07:08:33","slug":"topic-5-formulae-equations-and-amounts-of-substance","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/","title":{"rendered":"Topic 5 &#8211; Formulae, Equations and Amounts of Substance"},"content":{"rendered":"\n<div class=\"ols-t5-page\">\n\n  <aside class=\"ols-sidebar\">\r\n  <div class=\"ols-sidebar-header\">\r\n    <h3>Revision Notes<\/h3>\r\n    <p>A Level Chemistry<\/p>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Topic 5 Formulae, Equations and Amounts of Substance<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/atoms-elements-and-molecules\/\">Atoms, Elements and Molecules<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/equations-and-reaction-types\/\">Equations and Reaction Types<\/a>\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/equations-and-reaction-types\/writing-chemical-equations\/\">Writing Chemical Equations<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/equations-and-reaction-types\/typical-reactions-of-acids\/\">Typical Reactions of Acids<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/equations-and-reaction-types\/ionic-and-full-equations\/\">Ionic and Full Equations<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/mole-calculations\/\">Mole Calculations<\/a>\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/mole-calculations\/comparing-masses-of-substances\/\">Comparing Masses of Substances<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/mole-calculations\/calculations-involving-moles\/\">Calculations involving Moles<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/mole-calculations\/calculations-using-reacting-masses\/\">Calculations using Reacting Masses<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/mole-calculations\/the-yield-of-a-reaction\/\">The Yield of a Reaction<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/mole-calculations\/atom-economy\/\">Atom Economy<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/empirical-and-molecular-formulae\/\">Empirical and Molecular Formulae<\/a>\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/empirical-and-molecular-formulae\/empirical-formulae\/\">Empirical Formulae<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/empirical-and-molecular-formulae\/molecular-formulae\/\">Molecular Formulae<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/calculations-with-solutions-and-gases\/\">Calculations with Solutions and Gases<\/a>\r\n        <ul class=\"ols-subtopic-list\">\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/calculations-with-solutions-and-gases\/molar-volume-calculations\/\">Molar Volume Calculations<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/calculations-with-solutions-and-gases\/concentrations-of-solutions\/\">Concentrations of Solutions<\/a>\r\n          <\/li>\r\n          <li>\r\n            <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/calculations-with-solutions-and-gases\/titration-calculations\/\">Titration Calculations<\/a>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/measurement-uncertainty-and-errors\/\">Measurement Uncertainty and Errors<\/a>\r\n      <\/li>\r\n\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/risks-hazards-and-practical-precautions\/\">Risks, Hazards and Practical Precautions<\/a>\r\n      <\/li>\r\n\r\n    <\/ul>\r\n  <\/div>\r\n\r\n  <div class=\"ols-topic-group\">\r\n    <h4>Next Topics<\/h4>\r\n\r\n    <ul class=\"ols-topic-list\">\r\n      <li>\r\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-6-organic-chemistry-i\/\">Topic 6 Organic Chemistry I<\/a>\r\n      <\/li>\r\n      <li>\r\n        <a 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href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/\">Revision Notes<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/\">A Level Chemistry<\/a> \/\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/\">Edexcel<\/a> \/\n        <span>Topic 5 Formulae, Equations and Amounts of Substance<\/span>\n      <\/nav>\n    <\/div>\n  <\/div>\n\n  <!-- INTRO -->\n  <section class=\"ols-t5-intro\">\n    <div class=\"ols-t5-container\">\n      <div class=\"ols-t5-intro-inner\">\n\n        <div>\n          <div class=\"ols-t5-eyebrow\">Edexcel A Level Chemistry<\/div>\n          <h1>Topic 5<br>Formulae, Equations<br>&amp; Amounts of Substance<\/h1>\n          <div class=\"ols-t5-accent-bar\"><\/div>\n          <p class=\"ols-t5-intro-lead\">\n            Topic 5 builds the calculation and chemical language foundation for A Level Chemistry. It covers atoms, elements, ions, molecules, compounds, empirical formulae, molecular formulae, balanced equations, reacting masses, solution concentrations, gas volumes, titration calculations, percentage yield, atom economy, measurement uncertainty, errors, risks and hazards.\n          <\/p>\n        <\/div>\n\n        <div class=\"ols-t5-info-grid\">\n          <div class=\"ols-t5-info-card\">\n            <div class=\"ols-t5-info-card-label\">Exam Paper<\/div>\n            <div class=\"ols-t5-info-card-value\">Paper 1<\/div>\n            <div class=\"ols-t5-info-card-sub\">9CH0\/01<\/div>\n          <\/div>\n          <div class=\"ols-t5-info-card\">\n            <div class=\"ols-t5-info-card-label\">Specification Points<\/div>\n            <div class=\"ols-t5-info-card-value\">5.1 &#8211; 5.16<\/div>\n            <div class=\"ols-t5-info-card-sub\">16 points covered<\/div>\n          <\/div>\n          <div class=\"ols-t5-info-card\">\n            <div class=\"ols-t5-info-card-label\">Topic Parts<\/div>\n            <div class=\"ols-t5-info-card-value\">7 parts<\/div>\n            <div class=\"ols-t5-info-card-sub\">Revision notes available<\/div>\n          <\/div>\n          <div class=\"ols-t5-info-card\">\n            <div class=\"ols-t5-info-card-label\">Exam Board<\/div>\n            <div class=\"ols-t5-info-card-value\">Edexcel<\/div>\n            <div class=\"ols-t5-info-card-sub\">Pearson 9CH0<\/div>\n          <\/div>\n        <\/div>\n\n      <\/div>\n    <\/div>\n  <\/section>\n\n  <!-- TOPIC CARDS -->\n  <section class=\"ols-t5-topics\">\n    <div class=\"ols-t5-container\">\n\n      <div class=\"ols-t5-section-header\">\n        <h2 class=\"ols-t5-section-title\">Revision Notes<\/h2>\n      <\/div>\n\n      <div class=\"ols-t5-cards-grid\">\n\n        <!-- Card 1: Atoms, Elements and Molecules -->\n        <a class=\"ols-t5-card ols-t5-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/atoms-elements-and-molecules\/\">\n          <div class=\"ols-t5-card-img-wrap\">\n            <div class=\"ols-t5-visual ols-t5-visual--particles\">\n              <div class=\"ols-t5-visual-panel\">\n                <div class=\"ols-t5-visual-kicker\">Chemical language<\/div>\n                <div class=\"ols-t5-particle-diagram\" aria-hidden=\"true\">\n                  <span class=\"ols-t5-particle-dot d1\"><\/span>\n                  <span class=\"ols-t5-particle-dot d2\"><\/span>\n                  <span class=\"ols-t5-particle-dot d3\"><\/span>\n                <\/div>\n                <div class=\"ols-t5-visual-main\">Atoms,<br>Elements<br>&amp; Molecules<\/div>\n                <div class=\"ols-t5-visual-sub\">atoms, ions, molecules, compounds and formulae<\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-t5-card-num\">1<\/div>\n            <span class=\"ols-t5-card-status ols-t5-card-status--available\">Available<\/span>\n          <\/div>\n          <div class=\"ols-t5-card-body\">\n            <p class=\"ols-t5-card-title\">Atoms, Elements and Molecules<\/p>\n            <p class=\"ols-t5-card-desc\">Key definitions including atom, element, ion, molecule, compound, empirical formula and molecular formula.<\/p>\n            <span class=\"ols-t5-card-cta\">\n              Start revising\n              <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>\n            <\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 2: Equations and Reaction Types -->\n        <a class=\"ols-t5-card ols-t5-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/equations-and-reaction-types\/\">\n          <div class=\"ols-t5-card-img-wrap\">\n            <div class=\"ols-t5-visual ols-t5-visual--equations\">\n              <div class=\"ols-t5-visual-panel\">\n                <div class=\"ols-t5-visual-kicker\">Equations and tests<\/div>\n                <div class=\"ols-t5-equation-line\" aria-hidden=\"true\">A + B \u2192 C<\/div>\n                <div class=\"ols-t5-visual-main\">Equations<br>&amp; Reaction<br>Types<\/div>\n                <div class=\"ols-t5-visual-sub\">balanced, ionic and full equations<\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-t5-card-num\">2<\/div>\n            <span class=\"ols-t5-card-status ols-t5-card-status--available\">Available<\/span>\n          <\/div>\n          <div class=\"ols-t5-card-body\">\n            <p class=\"ols-t5-card-title\">Equations and Reaction Types<\/p>\n            <p class=\"ols-t5-card-desc\">Balanced equations, ionic equations, state symbols, acid reactions and precipitation reactions.<\/p>\n            <span class=\"ols-t5-card-cta\">\n              Start revising\n              <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>\n            <\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 3: Mole Calculations -->\n        <a class=\"ols-t5-card ols-t5-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/mole-calculations\/\">\n          <div class=\"ols-t5-card-img-wrap\">\n            <div class=\"ols-t5-visual ols-t5-visual--moles\">\n              <div class=\"ols-t5-visual-panel\">\n                <div class=\"ols-t5-visual-kicker\">Amount of substance<\/div>\n                <div class=\"ols-t5-mole-stack\" aria-hidden=\"true\">\n                  <span><\/span><span><\/span><span><\/span>\n                <\/div>\n                <div class=\"ols-t5-visual-main\">Mole<br>Calculations<\/div>\n                <div class=\"ols-t5-visual-sub\">moles, Avogadro constant, mass and reacting quantities<\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-t5-card-num\">3<\/div>\n            <span class=\"ols-t5-card-status ols-t5-card-status--available\">Available<\/span>\n          <\/div>\n          <div class=\"ols-t5-card-body\">\n            <p class=\"ols-t5-card-title\">Mole Calculations<\/p>\n            <p class=\"ols-t5-card-desc\">The mole, Avogadro constant, molar mass, reacting masses, percentage yield and atom economy.<\/p>\n            <span class=\"ols-t5-card-cta\">\n              Start revising\n              <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>\n            <\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 4: Empirical and Molecular Formulae -->\n        <a class=\"ols-t5-card ols-t5-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/empirical-and-molecular-formulae\/\">\n          <div class=\"ols-t5-card-img-wrap\">\n            <div class=\"ols-t5-visual ols-t5-visual--formulae\">\n              <div class=\"ols-t5-visual-panel\">\n                <div class=\"ols-t5-visual-kicker\">Formulae from data<\/div>\n                <div class=\"ols-t5-formula-box\" aria-hidden=\"true\">C<sub>2<\/sub>H<sub>6<\/sub>O<\/div>\n                <div class=\"ols-t5-visual-main\">Empirical<br>&amp; Molecular<br>Formulae<\/div>\n                <div class=\"ols-t5-visual-sub\">formulae from experimental data and mass values<\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-t5-card-num\">4<\/div>\n            <span class=\"ols-t5-card-status ols-t5-card-status--available\">Available<\/span>\n          <\/div>\n          <div class=\"ols-t5-card-body\">\n            <p class=\"ols-t5-card-title\">Empirical and Molecular Formulae<\/p>\n            <p class=\"ols-t5-card-desc\">Using experimental data, percentage composition and molar mass to calculate empirical and molecular formulae.<\/p>\n            <span class=\"ols-t5-card-cta\">\n              Start revising\n              <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>\n            <\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 5: Calculations with Solutions and Gases -->\n        <a class=\"ols-t5-card ols-t5-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/calculations-with-solutions-and-gases\/\">\n          <div class=\"ols-t5-card-img-wrap\">\n            <div class=\"ols-t5-visual ols-t5-visual--solutions\">\n              <div class=\"ols-t5-visual-panel\">\n                <div class=\"ols-t5-visual-kicker\">Solutions and gases<\/div>\n                <div class=\"ols-t5-solution-icon\" aria-hidden=\"true\"><\/div>\n                <div class=\"ols-t5-visual-main\">Solutions<br>&amp; Gases<\/div>\n                <div class=\"ols-t5-visual-sub\">concentration, titrations and gas volumes<\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-t5-card-num\">5<\/div>\n            <span class=\"ols-t5-card-status ols-t5-card-status--available\">Available<\/span>\n          <\/div>\n          <div class=\"ols-t5-card-body\">\n            <p class=\"ols-t5-card-title\">Calculations with Solutions and Gases<\/p>\n            <p class=\"ols-t5-card-desc\">Concentrations, titration calculations, molar volume and reacting volumes of gases.<\/p>\n            <span class=\"ols-t5-card-cta\">\n              Start revising\n              <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>\n            <\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 6: Measurement Uncertainty and Errors -->\n        <a class=\"ols-t5-card ols-t5-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/measurement-uncertainty-and-errors\/\">\n          <div class=\"ols-t5-card-img-wrap\">\n            <div class=\"ols-t5-visual ols-t5-visual--uncertainty\">\n              <div class=\"ols-t5-visual-panel\">\n                <div class=\"ols-t5-visual-kicker\">Practical data<\/div>\n                <div class=\"ols-t5-uncertainty-icon\" aria-hidden=\"true\"><\/div>\n                <div class=\"ols-t5-visual-main\">Measurement<br>Uncertainty<br>&amp; Errors<\/div>\n                <div class=\"ols-t5-visual-sub\">error, uncertainty and precision<\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-t5-card-num\">6<\/div>\n            <span class=\"ols-t5-card-status ols-t5-card-status--available\">Available<\/span>\n          <\/div>\n          <div class=\"ols-t5-card-body\">\n            <p class=\"ols-t5-card-title\">Measurement Uncertainty and Errors<\/p>\n            <p class=\"ols-t5-card-desc\">Measurement errors, percentage uncertainty, sources of error and minimising uncertainty in practical work.<\/p>\n            <span class=\"ols-t5-card-cta\">\n              Start revising\n              <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>\n            <\/span>\n          <\/div>\n        <\/a>\n\n        <!-- Card 7: Risks, Hazards and Practical Precautions -->\n        <a class=\"ols-t5-card ols-t5-card--available\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel\/topic-5-formulae-equations-and-amounts-of-substance\/risks-hazards-and-practical-precautions\/\">\n          <div class=\"ols-t5-card-img-wrap\">\n            <div class=\"ols-t5-visual ols-t5-visual--hazards\">\n              <div class=\"ols-t5-visual-panel\">\n                <div class=\"ols-t5-visual-kicker\">Practical safety<\/div>\n                <div class=\"ols-t5-hazard-icon\" aria-hidden=\"true\"><\/div>\n                <div class=\"ols-t5-visual-main\">Risks,<br>Hazards<br>&amp; Precautions<\/div>\n                <div class=\"ols-t5-visual-sub\">hazards, risks and safe practical decisions<\/div>\n              <\/div>\n            <\/div>\n            <div class=\"ols-t5-card-num\">7<\/div>\n            <span class=\"ols-t5-card-status ols-t5-card-status--available\">Available<\/span>\n          <\/div>\n          <div class=\"ols-t5-card-body\">\n            <p class=\"ols-t5-card-title\">Risks, Hazards and Practical Precautions<\/p>\n            <p class=\"ols-t5-card-desc\">Understanding hazards, evaluating risks and suggesting appropriate precautions in practical procedures.<\/p>\n            <span class=\"ols-t5-card-cta\">\n              Start revising\n              <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>\n            <\/span>\n          <\/div>\n        <\/a>\n\n      <\/div>\n    <\/div>\n  <\/section>\n\n  <!-- SPECIFICATION -->\n  <section class=\"ols-t5-spec-section\">\n    <div class=\"ols-t5-container\">\n      <div class=\"ols-t5-spec-wrap\">\n        <div class=\"ols-t5-spec-pill\">Specification Coverage<\/div>\n        <h2 class=\"ols-t5-spec-heading\">Topic 5 Formulae, Equations and Amounts of Substance &#8211; Edexcel A Level Chemistry<\/h2>\n        <p class=\"ols-t5-spec-intro-text\">The following specification points outline the knowledge and skills students are expected to demonstrate for Topic 5. Ideas from this topic are applied across quantitative chemistry, practical work and later physical, inorganic and organic topics.<\/p>\n\n        <h3 class=\"ols-t5-spec-group-title\">Chemical Language and Formulae<\/h3>\n        <div class=\"ols-t5-spec-rows\">\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.3<\/div>\n            <div class=\"ols-t5-spec-text\">know that the molar mass of a substance is the mass per mole of the substance in g mol<sup>-1<\/sup><\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.4<\/div>\n            <div class=\"ols-t5-spec-text\">know what is meant by the terms empirical formula and molecular formula<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row ols-t5-spec-row--mid\">\n            <div class=\"ols-t5-spec-code\">5.5<\/div>\n            <div class=\"ols-t5-spec-text\">\n              be able to use experimental data to calculate empirical formulae and molecular formulae, including the use of <em>pV = nRT<\/em> for gases and volatile liquids.\n              <div class=\"ols-t5-spec-sub-list\">\n                <div class=\"ols-t5-spec-sub-row\">\n                  <div class=\"ols-t5-spec-sub-code\">i<\/div>\n                  <div class=\"ols-t5-spec-sub-text\">empirical formulae<\/div>\n                <\/div>\n                <div class=\"ols-t5-spec-sub-row\">\n                  <div class=\"ols-t5-spec-sub-code\">ii<\/div>\n                  <div class=\"ols-t5-spec-sub-text\">molecular formulae including the use of <em>pV = nRT<\/em> for gases and volatile liquids<\/div>\n                <\/div>\n              <\/div>\n              <em>Calculations of empirical formula may involve composition by mass or percentage composition by mass data.<\/em>\n            <\/div>\n          <\/div>\n        <\/div>\n\n        <h3 class=\"ols-t5-spec-group-title\">The Mole and Core Calculations<\/h3>\n        <div class=\"ols-t5-spec-rows\">\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.1<\/div>\n            <div class=\"ols-t5-spec-text\">know that the mole, mol, is the unit for amount of a substance<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.2<\/div>\n            <div class=\"ols-t5-spec-text\">be able to use the Avogadro constant, <em>L<\/em>, 6.02 &times; 10<sup>23<\/sup> mol<sup>-1<\/sup>, in calculations<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.7<\/div>\n            <div class=\"ols-t5-spec-text\">be able to calculate amounts of substances, in mol, in reactions involving mass, volume of gas, volume of solution and concentration. These calculations may involve reactants and\/or products.<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.8<\/div>\n            <div class=\"ols-t5-spec-text\">be able to calculate reacting masses from chemical equations, and vice versa, using the concepts of amount of substance and molar mass<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.9<\/div>\n            <div class=\"ols-t5-spec-text\">be able to calculate reacting volumes of gases from chemical equations, and vice versa, using the concepts of amount of substance<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.10<\/div>\n            <div class=\"ols-t5-spec-text\">be able to calculate reacting volumes of gases from chemical equations, and vice versa, using the concepts of molar volume of gases. <strong>Core Practical 1:<\/strong> measure the molar volume of a gas.<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.11<\/div>\n            <div class=\"ols-t5-spec-text\">be able to calculate solution concentrations, in mol dm<sup>-3<\/sup> and g dm<sup>-3<\/sup>, including simple acid-base titrations using a range of acids, alkalis and indicators. The use of both phenolphthalein and methyl orange as indicators will be expected.<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.14<\/div>\n            <div class=\"ols-t5-spec-text\">\n              be able to calculate percentage yields and percentage atom economies using chemical equations and experimental results.\n              <div class=\"ols-t5-spec-formula\">Atom economy = molar mass of the desired product &divide; sum of the molar masses of all products &times; 100%<\/div>\n            <\/div>\n          <\/div>\n        <\/div>\n\n        <h3 class=\"ols-t5-spec-group-title\">Equations, Reaction Types and Observations<\/h3>\n        <div class=\"ols-t5-spec-rows\">\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.6<\/div>\n            <div class=\"ols-t5-spec-text\">be able to write balanced full and ionic equations, including state symbols, for chemical reactions<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row ols-t5-spec-row--mid\">\n            <div class=\"ols-t5-spec-code\">5.15<\/div>\n            <div class=\"ols-t5-spec-text\">\n              be able to relate ionic and full equations, with state symbols, to observations from simple test tube reactions.\n              <div class=\"ols-t5-spec-sub-list\">\n                <div class=\"ols-t5-spec-sub-row\">\n                  <div class=\"ols-t5-spec-sub-code\">i<\/div>\n                  <div class=\"ols-t5-spec-sub-text\">displacement reactions<\/div>\n                <\/div>\n                <div class=\"ols-t5-spec-sub-row\">\n                  <div class=\"ols-t5-spec-sub-code\">ii<\/div>\n                  <div class=\"ols-t5-spec-sub-text\">reactions of acids<\/div>\n                <\/div>\n                <div class=\"ols-t5-spec-sub-row\">\n                  <div class=\"ols-t5-spec-sub-code\">iii<\/div>\n                  <div class=\"ols-t5-spec-sub-text\">precipitation reactions<\/div>\n                <\/div>\n              <\/div>\n            <\/div>\n          <\/div>\n        <\/div>\n\n        <h3 class=\"ols-t5-spec-group-title\">Uncertainty, Errors and Practical Safety<\/h3>\n        <div class=\"ols-t5-spec-rows\">\n          <div class=\"ols-t5-spec-row ols-t5-spec-row--mid\">\n            <div class=\"ols-t5-spec-code\">5.12<\/div>\n            <div class=\"ols-t5-spec-text\">\n              be able to calculate measurement uncertainties and measurement errors in experimental results, and comment on sources of error in experimental procedures.\n              <div class=\"ols-t5-spec-sub-list\">\n                <div class=\"ols-t5-spec-sub-row\">\n                  <div class=\"ols-t5-spec-sub-code\">i<\/div>\n                  <div class=\"ols-t5-spec-sub-text\">calculate measurement uncertainties and measurement errors in experimental results<\/div>\n                <\/div>\n                <div class=\"ols-t5-spec-sub-row\">\n                  <div class=\"ols-t5-spec-sub-code\">ii<\/div>\n                  <div class=\"ols-t5-spec-sub-text\">comment on sources of error in experimental procedures<\/div>\n                <\/div>\n              <\/div>\n            <\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.13<\/div>\n            <div class=\"ols-t5-spec-text\">understand how to minimise the percentage error and percentage uncertainty in experiments involving measurements<\/div>\n          <\/div>\n          <div class=\"ols-t5-spec-row\">\n            <div class=\"ols-t5-spec-code\">5.16<\/div>\n            <div class=\"ols-t5-spec-text\">understand risks and hazards in practical procedures and suggest appropriate precautions where necessary<\/div>\n          <\/div>\n        <\/div>\n\n      <\/div>\n    <\/div>\n  <\/section>\n\n<script type=\"application\/ld+json\">\n{\n  \"@context\": 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