{"id":8096,"date":"2026-09-15T08:35:00","date_gmt":"2026-09-15T07:35:00","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/measuring-mass-volume-and-gas-volume\/"},"modified":"2026-09-22T16:37:05","modified_gmt":"2026-09-22T15:37:05","slug":"measuring-mass-volume-and-gas-volume","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/measuring-mass-volume-and-gas-volume\/","title":{"rendered":"Measuring Mass, Volume and Gas Volume"},"content":{"rendered":"\n<!--\n===============================================================================\nONLINE LEARNING SYSTEM COPYRIGHT NOTICE\n\u00a9 Online Learning System. 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background: #2563eb !important;\n      color: #ffffff !important;\n    }\n\n    body.ols-lightbox-lock {\n      overflow: hidden !important;\n    }\n\n    @media (max-width: 760px) {\n      .ols-zoom-card {\n        border-radius: 22px !important;\n        overflow: hidden !important;\n      }\n\n      .ols-zoom-card-image {\n        min-height: auto !important;\n        padding: 12px !important;\n        overflow: hidden !important;\n        border-top-left-radius: 22px !important;\n        border-top-right-radius: 22px !important;\n      }\n\n      .ols-zoom-card img.ols-zoomable-img,\n      .ols-zoom-card img.ols-zoomable-img:hover {\n        transform: none !important;\n        box-shadow: none !important;\n      }\n\n      .ols-zoom-card-caption {\n        border-bottom-left-radius: 22px !important;\n        border-bottom-right-radius: 22px !important;\n      }\n\n      .ols-image-lightbox {\n        padding: 14px !important;\n      }\n\n      .ols-image-lightbox-img {\n        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<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 = 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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<\/a> \/\n<a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/\">2.1.3 Amount of Substance<\/a> \/\n<span>Measuring Mass, Volume and Gas Volume<\/span>\n<\/nav>\n\n      <header class=\"ols-title-card\">\n        <h1>Measuring Mass, Volume and Gas Volume<\/h1>\n        <p class=\"ols-page-intro\">A concise OCR A Level Chemistry A revision guide to the techniques and procedures for measuring mass, volumes of solutions and volumes of gases in quantitative experiments, and the uncertainty each brings (2.1.3(i)).<\/p>\n\n        <div class=\"ols-badges\">\n<div class=\"ols-badge\">Paper 1 and 2<\/div>\n<div class=\"ols-badge\">2.1.3 Amount of Substance<\/div>\n<div class=\"ols-badge\">H432\/01 and H432\/02<\/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          <div class=\"ols-author-content\">\n            <h2 class=\"ols-author-title\">Written by:<br><span>Dr. Mohammed Al-Fatah<\/span><\/h2>\n            <p class=\"ols-author-description\">Chemistry specialist revision notes for A Level Chemistry.<\/p>\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\"><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><\/svg>\n              View LinkedIn Profile\n            <\/a>\n          <\/div>\n        <\/div>\n      <\/header>\n\n      <section class=\"ols-h5p-card ols-h5p-inline ols-h5p-recap\">\n<span class=\"ols-h5p-kicker\">Before you start<\/span>\n<h2>GCSE Recap: Volumes, Gases and Balances<\/h2>\n<p>Before you start, check three measuring ideas you already met at GCSE.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-content\" data-content-id=\"761\"><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">1<\/div>\n<h2>Measuring Mass<\/h2>\n<\/div>\n<p>Masses are measured on a <strong>balance<\/strong> reading to two or three decimal places. For a solid that will be transferred, <strong>weigh by difference<\/strong>: weigh the weighing boat with the solid, tip the solid into the vessel, then reweigh the boat. The difference is the mass actually transferred, so any solid stuck to the boat does not count.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Situation<\/th><th>Technique<\/th><th>Why<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Solid for a standard solution<\/strong><\/td><td>Weigh by difference into the beaker<\/td><td>Only the mass that reached the beaker enters the calculation<\/td><\/tr>\n<tr><td><strong>Hydrated salt to be heated<\/strong><\/td><td>Weigh crucible empty, with salt, and after each heating<\/td><td>Mass changes are followed to constant mass<\/td><\/tr>\n<tr><td><strong>Hygroscopic solid (e.g. NaOH)<\/strong><\/td><td>Weigh quickly with the lid on<\/td><td>It absorbs water from the air and gains mass while you watch<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Key idea:<\/strong> The uncertainty of a balance is \u00b1 half its last digit per reading; weighing by difference involves two readings, so the uncertainty doubles.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Weighing by Difference<\/h2>\n<p>Type the mass, or the missing word, for each of these weighings.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-509\" class=\"h5p-iframe\" data-content-id=\"509\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Measuring Mass Fill In: Weighing by Difference\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">2<\/div>\n<h2>Measuring Volumes of Solutions<\/h2>\n<\/div>\n<p>Different glassware suits different jobs. The choice is about <strong>precision<\/strong>: how closely the true volume matches the reading.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Apparatus<\/th><th>Typical uncertainty<\/th><th>Used for<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Volumetric (graduated) pipette, 25.0 cm\u00b3<\/strong><\/td><td>\u00b1 0.06 cm\u00b3<\/td><td>Transferring one exact volume, e.g. the sample to be titrated<\/td><\/tr>\n<tr><td><strong>Burette, 50.00 cm\u00b3<\/strong><\/td><td>\u00b1 0.05 cm\u00b3 per reading<\/td><td>Delivering a variable volume and reading it to 0.05 cm\u00b3<\/td><\/tr>\n<tr><td><strong>Volumetric flask, 250 cm\u00b3<\/strong><\/td><td>\u00b1 0.3 cm\u00b3<\/td><td>Making up a standard solution to an exact volume<\/td><\/tr>\n<tr><td><strong>Measuring cylinder, 50 cm\u00b3<\/strong><\/td><td>\u00b1 0.5 cm\u00b3<\/td><td>Rough volumes where precision does not matter, e.g. solvent for dissolving<\/td><\/tr>\n<tr><td><strong>Beaker<\/strong><\/td><td>Not calibrated for measurement<\/td><td>Holding and mixing only<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>Read every meniscus at eye level with the bottom of the curve on the line. Rinse a pipette and burette with the solution they will hold, never with water, or the concentration is diluted.<\/p>\n<div class=\"ols-zoom-card\">\n<div class=\"ols-figure-card\">\n<div class=\"ols-figure-image\"><img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/fix-55.jpg\" alt=\"Three panels of measuring apparatus: balance and weighing boat, pipette, burette and volumetric flask with uncertainties, gas syringe and gas collected over water\"><\/div>\n<div class=\"ols-figure-caption\"><p>Three-panel diagram of laboratory apparatus: an analytical balance with a weighing boat, a volumetric pipette, burette and volumetric flask with their uncertainties, and a gas syringe and upturned measuring cylinder over water for collecting gas<\/p><\/div>\n<\/div>\n<div class=\"ols-zoom-card-caption\"><p>Mass by difference, exact volumes by pipette, burette and volumetric flask, and gas volumes by syringe or displacement of water.<\/p><\/div>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Pick the Apparatus<\/h2>\n<p>Five jobs, five pieces of apparatus: choose the right one for each.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-506\" class=\"h5p-iframe\" data-content-id=\"506\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Choosing Apparatus Quick Fire: The Right Glassware for Each Job\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card purple\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">3<\/div>\n<h2>Measuring Volumes of Gases<\/h2>\n<\/div>\n<p>A gas made in a reaction is collected and its volume measured in one of two ways.<\/p>\n<ul>\n<li><strong>Gas syringe:<\/strong> the reaction flask is sealed and connected to a syringe whose plunger moves out as gas forms. Precise (\u00b1 0.5 cm\u00b3 on a 100 cm\u00b3 syringe) and works for any gas, but the syringe can stick and the volume is limited to 100 cm\u00b3.<\/li>\n<li><strong>Displacement of water:<\/strong> the gas is led by a delivery tube into an upturned measuring cylinder or burette full of water; the water level falls as gas collects. Simple, but useless for gases that dissolve in water such as ammonia, hydrogen chloride or, partly, carbon dioxide.<\/li>\n<\/ul>\n<p>Record the temperature and pressure: a gas volume only has meaning at stated conditions, and converting it to moles uses either the molar gas volume (24.0 dm\u00b3 mol\u207b\u00b9 at RTP) or pV = nRT.<\/p>\n<div class=\"ols-key-box\">\n<p><strong>Exam sentence:<\/strong> A gas syringe measures the volume of gas directly; collection over water fails for soluble gases because some of the gas dissolves.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: Measuring a Larger Volume of Gas<\/h2>\n<p>Decide how this gas should be collected and measured.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-508\" class=\"h5p-iframe\" data-content-id=\"508\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Measuring Gas Volumes MCQ: Choosing a Method for 250 cm\u00b3 of Gas\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card orange\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">4<\/div>\n<h2>Percentage Uncertainty<\/h2>\n<\/div>\n<p>Each measurement carries an uncertainty, and the exam asks you to compare them.<\/p>\n<p style=\"text-align:center;font-size:1.15em\"><strong>% uncertainty = (uncertainty of the apparatus \u00f7 quantity measured) \u00d7 100<\/strong><\/p>\n<p>A burette reading has an uncertainty of \u00b1 0.05 cm\u00b3, and a titre uses two readings, so a titre of 23.40 cm\u00b3 has an uncertainty of \u00b1 0.10 cm\u00b3: 0.10 \/ 23.40 \u00d7 100 = <strong>0.43%<\/strong>. A mass of 0.120 g on a two-decimal-place balance (\u00b1 0.005 g per reading, two readings) has 0.010 \/ 0.120 \u00d7 100 = <strong>8.3%<\/strong>, so the mass is the measurement to improve, for example by weighing a larger sample.<\/p>\n<div class=\"ols-key-box\">\n<p><strong>Key idea:<\/strong> To reduce a percentage uncertainty, measure a larger quantity with the same apparatus or use more precise apparatus.<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: The Weakest Measurement<\/h2>\n<p>Work out both percentage uncertainties before you choose.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-507\" class=\"h5p-iframe\" data-content-id=\"507\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Percentage Uncertainty MCQ: Which Measurement Limits the Experiment\"><\/iframe><\/div><\/div>\n<\/section>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Quick Check: What Actually Improves a Measurement<\/h2>\n<p>In each round, pick the one statement that is accurate.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-762\" class=\"h5p-iframe\" data-content-id=\"762\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Measuring Techniques Summary: Making a Measurement Better\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">5<\/div>\n<h2>Common Exam Mistakes<\/h2>\n<\/div>\n<ul>\n<li>Rinsing the pipette or burette with water before use, which dilutes the solution.<\/li>\n<li>Using a measuring cylinder where a pipette or volumetric flask is required.<\/li>\n<li>Collecting a soluble gas over water.<\/li>\n<li>Forgetting that a titre is the difference of two burette readings, so its uncertainty is twice the reading uncertainty.<\/li>\n<\/ul>\n<div class=\"ols-key-box\">\n<p><strong>Exam sentence:<\/strong> Use a pipette for a fixed exact volume, a burette for a variable volume read to 0.05 cm\u00b3, and a volumetric flask to make up a solution to an exact volume.<\/p>\n<\/div>\n<\/article>\n\n<section class=\"ols-related-card\">\n        <h2>Related Topics<\/h2>\n        <p>Continue through this section by linking this page to equations, formulae and mole calculation revision.<\/p>\n        <div class=\"ols-related-grid\">\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-2-compounds-formulae-and-equations\/equations-and-reaction-types\/\">Equations and Reaction Types<\/a>\n          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-2-compounds-formulae-and-equations\/equations-and-reaction-types\/writing-chemical-equations\/\">Writing Chemical Equations<\/a>\n          <a class=\"ols-related-item\" 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          <a class=\"ols-related-item\" 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          <a class=\"ols-related-item\" 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          <a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-1-atomic-structure-and-isotopes\/\">Atomic Structure &amp; The Periodic Table<\/a>\n        <\/div>\n      <\/section>\n\n      <section class=\"ols-attribution-card\">\n        <p><strong>Copyright notice:<\/strong> This OLS revision content, including the explanations, layout, diagrams, tables and embedded learning structure, is authored for Online Learning System by Dr. Mohammed Al-Fatah. It may not be copied, reproduced, redistributed or adapted without written permission.<\/p>\n      <\/section>\n\n      <script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@graph\": [\n    {\n      \"@type\": \"WebPage\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/ocr-a\/2-1-3-amount-of-substance\/measuring-mass-volume-and-gas-volume\/#webpage\",\n      \"url\": \"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      \"name\": \"Measuring Mass, Volume and Gas Volume - OCR A Level Chemistry A\",\n      \"description\": \"OCR A Level Chemistry A 2.1.3(i) revision notes: measuring mass by difference, using pipettes, burettes and volumetric flasks, collecting gases with a gas syringe or over water, and percentage uncertainty.\",\n      \"inLanguage\": \"en-GB\",\n      \"isPartOf\": {\n      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