Subject Content - GCSE Chemistry
Subject content
The GCSE Chemistry A specification content is organised into teaching topics C1-C6 and the practical skills topic C7. The tables below summarise the content learners need to know, understand, and apply.
Statements shown as Higher-only in the specification are included here inside the relevant topic focus so teachers and learners can see where additional depth is expected.
Summary of content
| Topic | Sub-topics |
|---|---|
| Topic C1: Particles | C1.1 The particle model C1.2 Atomic structure |
| Topic C2: Elements, compounds and mixtures | C2.1 Purity and separating mixtures C2.2 Bonding C2.3 Properties of materials |
| Topic C3: Chemical reactions | C3.1 Introducing chemical reactions C3.2 Energetics C3.3 Types of chemical reactions C3.4 Electrolysis |
| Topic C4: Predicting and identifying reactions and products | C4.1 Predicting chemical reactions C4.2 Identifying products of chemical reactions |
| Topic C5: Monitoring and controlling chemical reactions | C5.1 Monitoring chemical reactions C5.2 Controlling reactions C5.3 Equilibria |
| Topic C6: Global challenges | C6.1 Improving processes and products C6.2 Organic chemistry C6.3 Interpreting and interacting with Earth systems |
| Topic C7: Practical skills | Practical Activity Groups C1-C8 and the apparatus, techniques, measurement, analysis, and evaluation skills used across the course |
Topics C1 to C6
These detailed chapter rows keep the reference structure of the specification while grouping the learning outcome, inclusion notes, maths links, working scientifically links, and practical suggestions into clear tables.
Topic C1: Particles
| Reference | Learning outcomes | To include | Maths | Working scientifically | Practical suggestions |
|---|---|---|---|---|---|
| C1.1a | Describe the main features of the particle model in terms of states of matter and change of state. | M5b | WS1.1a, WS1.1b | ||
| C1.1b | Explain, in terms of the particle model, the distinction between physical changes and chemical changes. | ||||
| C1.1c | Explain the limitations of the particle model in relation to changes of state when particles are represented by inelastic spheres. | The model does not take into account the forces of attraction between particles, the size of particles, and the space between them. | M5b | WS1.1c | Observe changes of state and compare them with chemical changes. |
| C1.2a | Describe how and why the atomic model has changed over time. | Models of Dalton, Thomson, Rutherford, Bohr, Geiger and Marsden. | WS1.1a, WS1.1i, WS1.2b | Timeline of the atomic model. | |
| C1.2b | Describe the atom as a positively charged nucleus surrounded by negatively charged electrons, with the nuclear radius much smaller than that of the atom and with most of the mass in the nucleus. | WS1.4a | |||
| C1.2c | Recall the typical size, by order of magnitude, of atoms and small molecules. | Typical atomic radii and bond lengths are in the order of 10^-10 m. | M1c, M4a | WS1.1c, WS1.4b, WS1.4c, WS1.4d, WS1.4e, WS1.4f | |
| C1.2d | Recall relative charges and approximate relative masses of protons, neutrons and electrons. | WS1.4a, WS1.4b, WS1.4c | |||
| C1.2e | Calculate numbers of protons, neutrons and electrons in atoms and ions, given atomic number and mass number of isotopes. | Definitions of ion, atomic number, mass number and isotope; standard notation used to represent these. | WS1.3c, WS1.4b |
Topic C2: Elements, compounds and mixtures
| Reference | Learning outcomes | To include | Maths | Working scientifically | Practical suggestions |
|---|---|---|---|---|---|
| C2.1a | Explain what is meant by the purity of a substance, distinguishing between the scientific and everyday use of the term pure. | WS1.4a | Purification of compounds. (PAG C4, PAG C7) | ||
| C2.1b | Use melting point data to distinguish pure from impure substances. | M1a, M1c, M1d, M2a | Measurement of melting point. | ||
| C2.1c | Calculate relative formula masses of species separately and in a balanced chemical equation. | Relative atomic mass, relative molecular mass and relative formula mass. | M3b, M3c | WS1.3c, WS1.4c | |
| C2.1d | Deduce the empirical formula of a compound from the relative numbers of atoms present or from a model or diagram, and vice versa. | M3b, M3c | WS1.1b, WS1.4a | ||
| C2.1e | Explain that many useful materials are formulations of mixtures. | Alloys. | |||
| C2.1f | Describe, explain and exemplify filtration, crystallisation, simple distillation and fractional distillation. | Knowledge of the techniques of filtration, crystallisation, simple distillation and fractional distillation. | WS1.2b, WS1.2c, WS2a, WS2b | Separation of mixtures and purification of compounds. Distillation of mixtures. (PAG C4, PAG C7) | |
| C2.1g | Describe the techniques of paper and thin layer chromatography. | Using aqueous and non-aqueous solvents and locating agents. | WS1.2b, WS1.2c, WS1.4a, WS2a, WS2b | Paper or thin layer chromatography. (PAG C3) | |
| C2.1h | Recall that chromatography involves a stationary and a mobile phase and that separation depends on the distribution between the phases. | Identification of the mobile and stationary phases. | WS1.4a | ||
| C2.1i | Interpret chromatograms, including measuring Rf values. | Recall and use the formula for Rf. | M3b, M3c | WS1.3c, WS1.4a | |
| C2.1j | Suggest suitable purification techniques given information about the substances involved. | ||||
| C2.1k | Suggest chromatographic methods for distinguishing pure from impure substances. | Paper chromatography, thin layer chromatography (TLC) and gas chromatography. | WS1.4a | Use chromatography to identify mixtures of dyes in an unknown ink. (PAG C3) | |
| C2.2a | Describe metals and non-metals and explain the differences between them on the basis of their characteristic physical and chemical properties. | Physical properties, formation of ions and common reactions, for example with oxygen to form oxides. | WS1.3f, WS1.4a | ||
| C2.2b | Explain how the atomic structure of metals and non-metals relates to their position in the Periodic Table. | ||||
| C2.2c | Explain how the position of an element in the Periodic Table is related to the arrangement of electrons in its atoms and hence to its atomic number. | Group number and period number. | M1c | WS1.4a | |
| C2.2d | Describe and compare the nature and arrangement of chemical bonds in ionic compounds, simple molecules, giant covalent structures, polymers and metals. | M5b, M4a | WS1.4a | Make ball and stick models of molecules. | |
| C2.2e | Explain chemical bonding in terms of electrostatic forces and the transfer or sharing of electrons. | WS1.4a | |||
| C2.2f | Construct dot and cross diagrams for simple covalent and binary ionic substances. | M4a | WS1.4a | ||
| C2.2g | Describe the limitations of particular representations and models. | Dot and cross diagrams, ball and stick models, and two- and three-dimensional representations. | M5b | WS1.1c | |
| C2.2h | Explain how the reactions of elements are related to the arrangement of electrons in their atoms and hence to their atomic number. | WS1.1b, WS1.3f, WS1.4a | |||
| C2.2i | Explain in terms of atomic number how Mendeleev's arrangement was refined into the modern Periodic Table. | WS1.1a, WS1.4a | |||
| C2.3a | Recall that carbon can form four covalent bonds. | WS1.4a | |||
| C2.3b | Explain that the vast array of natural and synthetic organic compounds occur due to the ability of carbon to form families of similar compounds, chains and rings. | ||||
| C2.3c | Explain the properties of diamond, graphite, fullerenes and graphene in terms of their structures and bonding. | M5b | WS1.4a | ||
| C2.3d | Use ideas about energy transfers and the relative strength of chemical bonds and intermolecular forces to explain the different temperatures at which changes of state occur. | WS1.2a, WS1.3f, WS1.4a, WS1.4c | |||
| C2.3e | Use data to predict states of substances under given conditions. | Data such as temperature and how this may be linked to changes of state. | |||
| C2.3f | Explain how the bulk properties of materials are related to their different bond types, bond strengths and bond arrangements. | Ionic compounds, simple molecules, giant covalent structures, polymers and metals; recognise that the atoms themselves do not have the bulk properties of these materials. | WS1.4a | ||
| C2.3g | Higher tier only: compare nano dimensions to typical dimensions of atoms and molecules. | M4a, M1d, M1b | WS1.4c, WS1.4d | ||
| C2.3h | Higher tier only: describe the surface area to volume relationship for different-sized particles and describe how this affects properties. | M1c | WS1.4c | Dissolving tablets. (PAG C8) | |
| C2.3i | Higher tier only: describe how the properties of nanoparticulate materials are related to their uses. | M5c | WS1.1c, WS1.1e, WS1.3c, WS1.4a | ||
| C2.3j | Higher tier only: explain the possible risks associated with some nanoparticulate materials. | WS1.1d, WS1.1f, WS1.1h, WS1.1i, WS1.4a |
Topic C3: Chemical reactions
| Reference | Learning outcomes | To include | Maths | Working scientifically | Practical suggestions |
|---|---|---|---|---|---|
| C3.1a | Use chemical symbols to write the formulae of elements and simple covalent and ionic compounds. | M1a, M1c | WS1.4a | ||
| C3.1b | Use the names and symbols of common elements and compounds and the principle of conservation of mass to write formulae, balanced chemical equations and half equations. | M1a, M1c | WS1.4c | ||
| C3.1c | Use names and symbols of common elements from a supplied Periodic Table to write formulae and balanced chemical equations where appropriate. | The first 20 elements, Groups 1, 7 and 0, and other common elements included within the specification. | |||
| C3.1d | Use the formula of common ions to deduce the formula of a compound. | M1a, M1c | |||
| C3.1e | Construct balanced ionic equations. | M1a, M1c | |||
| C3.1f | Describe the physical states of products and reactants using state symbols (s, l, g and aq). | ||||
| C3.1g | Recall and use the definitions of the Avogadro constant, in standard form, and of the mole. | Calculate the mass of one atom or molecule. Both classical carbon-12 based and revised Avogadro-constant based mole definitions may be accepted. | M1b, M1c | WS1.4b, WS1.4c, WS1.4d, WS1.4f | |
| C3.1h | Explain how the mass of a given substance is related to the amount of that substance in moles and vice versa. | M1c, M2a | WS1.4b, WS1.4c | ||
| C3.1i | Recall and use the law of conservation of mass. | WS1.4c | |||
| C3.1j | Explain observed changes in mass in non-enclosed systems during a chemical reaction using the particle model. | WS1.1b, WS1.4c | |||
| C3.1k | Deduce the stoichiometry of an equation from the masses of reactants and products and explain the effect of a limiting quantity of a reactant. | M1c | WS1.3c, WS1.4c, WS1.4d, WS1.4f | ||
| C3.1l | Use a balanced equation to calculate masses of reactants or products. | M1c | WS1.3c, WS1.4c | ||
| C3.2a | Distinguish between endothermic and exothermic reactions on the basis of the temperature change of the surroundings. | WS1.4c | Measure the temperature change in reactions. (PAG C8) | ||
| C3.2b | Draw and label a reaction profile for an exothermic and an endothermic reaction. | Activation energy, energy change, reactants and products. | M4a | WS1.3b, WS1.3c, WS1.3d, WS1.3e, WS1.3g, WS1.3h, WS1.4c | |
| C3.2c | Explain activation energy as the energy needed for a reaction to occur. | WS1.4c | |||
| C3.2d | Calculate energy changes in a chemical reaction by considering bond making and bond breaking energies. | M1a | WS1.3c, WS1.4c | ||
| C3.3a | Explain reduction and oxidation in terms of loss or gain of oxygen, identifying which species are oxidised and which are reduced. | The concept of oxidising agent and reducing agent. | WS1.4a | ||
| C3.3b | Explain reduction and oxidation in terms of gain or loss of electrons, identifying which species are oxidised and which are reduced. | WS1.4a | |||
| C3.3c | Recall that acids form hydrogen ions when they dissolve in water and solutions of alkalis contain hydroxide ions. | WS1.4a | |||
| C3.3d | Describe neutralisation as acid reacting with alkali or a base to form a salt plus water. | WS1.4a | Produce a pure dry sample of salt. (PAG C7) | ||
| C3.3e | Recognise that aqueous neutralisation reactions can be generalised to hydrogen ions reacting with hydroxide ions to form water. | WS1.4a | |||
| C3.3f | Recall that carbonates and some metals react with acids and write balanced equations predicting products from given reactants. | WS1.4a | |||
| C3.3g | Use and explain the terms dilute and concentrated, and weak and strong, in relation to acids. | Dilute/concentrated refer to amount of substance; weak/strong refer to degree of ionisation. Include ratio of amount of acid to volume of solution. | M1a, M1c, M1d | WS1.4a | |
| C3.3h | Recall that relative acidity and alkalinity are measured by pH. | WS1.4a | |||
| C3.3i | Describe neutrality and relative acidity and alkalinity in terms of the effect of hydrogen ion concentration on pH, using whole numbers only. | pH of titration curves. | WS1.4a | Neutralisation reactions. (PAG C6) | |
| C3.3j | Use the idea that as hydrogen ion concentration increases by a factor of ten, the pH value of a solution decreases by one. | M1a, M1c, M1d | WS1.4a | ||
| C3.3k | Describe techniques and apparatus used to measure pH. | Universal indicator and pH meters. | Determine pH of unknown solutions and use pH probes. (PAG C6) | ||
| C3.4a | Recall that metals or hydrogen are formed at the cathode and non-metals are formed at the anode in electrolysis using inert electrodes. | The terms cations and anions. | WS1.4a | ||
| C3.4b | Predict the products of electrolysis of binary ionic compounds in the molten state. | Compounds such as NaCl. | M1a, M1c | WS1.2a, WS1.2b, WS1.2c, WS1.4a, WS2a, WS2b | |
| C3.4c | Describe competing reactions in the electrolysis of aqueous solutions of ionic compounds in terms of the different species present. | Electrolysis of aqueous NaCl and CuSO4 using inert electrodes. | M1a, M1c | WS1.4a | Electrolysis of sodium chloride solution and copper sulfate solution. (PAG C2) |
| C3.4d | Describe electrolysis in terms of the ions present and reactions at the electrodes. | Equations and half equations of reactions at the electrodes. | M1a, M1c | ||
| C3.4e | Describe the technique of electrolysis using inert and non-inert electrodes. |
Topic C4: Predicting and identifying reactions and products
| Reference | Learning outcomes | To include | Maths | Working scientifically | Practical suggestions |
|---|---|---|---|---|---|
| C4.1a | Recall the simple properties of Groups 1, 7 and 0. | Physical and chemical properties. | WS1.2a, WS1.4a, WS1.4c | Displacement reactions of halogens with halides. (PAG C1) | |
| C4.1b | Explain how observed simple properties of Groups 1, 7 and 0 depend on the outer shell of electrons of the atoms and predict properties from given trends down the groups. | Ease of electron gain or loss; physical and chemical properties. | |||
| C4.1c | Higher tier only: recall the general properties of transition metals and their compounds and exemplify these by reference to a small number of transition metals. | Melting point, density, reactivity, formation of coloured ions with different charges and uses as catalysts. | WS1.4a | Investigate transition metals. (PAG C1, PAG C5, PAG C8) | |
| C4.1d | Predict possible reactions and probable reactivity of elements from their positions in the Periodic Table. | WS1.1b, WS1.2a, WS1.4a | |||
| C4.1e | Explain how the reactivity of metals with water or dilute acids is related to the tendency of the metal to form its positive ion. | M1a, M1c | WS1.4a | Reactions of metals with water and dilute hydrochloric acid. (PAG C1, PAG C7, PAG C8) | |
| C4.1f | Deduce an order of reactivity of metals based on experimental results. | WS1.3e, WS2a | Displacement reactions involving metals and metal salts. (PAG C1, PAG C7, PAG C8) | ||
| C4.2a | Describe tests to identify selected gases. | Oxygen, hydrogen, carbon dioxide and chlorine. | |||
| C4.2b | Higher tier only: describe tests to identify aqueous cations and aqueous anions. | Calcium, copper, iron(II), iron(III) and zinc using sodium hydroxide; tests for carbonate, chloride, bromide, iodide and sulfate ions. | WS1.4a | Tests for cations using sodium hydroxide. Tests for anions using silver nitrate and barium chloride or nitrate. (PAG C5) | |
| C4.2c | Higher tier only: describe how to perform a flame test. | WS1.2b, WS1.2c, WS2a, WS2b | Flame tests. (PAG C5) | ||
| C4.2d | Higher tier only: identify species from test results. | Test unknown solutions for cations and anions. (PAG C5) | |||
| C4.2e | Higher tier only: interpret flame tests to identify metal ions. | Ions of lithium, sodium, potassium, calcium and copper. | WS1.4a | ||
| C4.2f | Higher tier only: describe the advantages of instrumental methods of analysis. | Sensitivity, accuracy and speed. | WS1.1e, WS1.2c, WS1.2d, WS1.2e | ||
| C4.2g | Higher tier only: interpret an instrumental result given appropriate data in chart or tabular form, when accompanied by a reference set of data in the same form. | Features of a mass spectroscopy chart. | M4a | WS1.3e |
Topic C5: Monitoring and controlling chemical reactions
| Reference | Learning outcomes | To include | Maths | Working scientifically | Practical suggestions |
|---|---|---|---|---|---|
| C5.1a | Higher tier only: explain how the concentration of a solution in mol/dm3 is related to the mass of the solute and the volume of the solution. | M1b | WS1.3c, WS1.4a, WS1.4c | Make standard solutions. | |
| C5.1b | Higher tier only: describe the technique of titration. | Acid/alkali titrations. (PAG C6) | |||
| C5.1c | Higher tier only: explain the relationship between the volume of a solution of known concentration and the volume or concentration of another substance that react completely together. | Titration calculations. | M2a, M1c | WS1.3c, WS1.4a, WS1.4b, WS1.4c | |
| C5.1d | Higher tier only: describe the relationship between molar amounts of gases and their volumes and vice versa. | M1c | WS1.3c, WS1.4a, WS1.4c, WS1.4d, WS1.4f | Measure gas volumes and calculate amount in moles. (PAG C8) | |
| C5.1e | Higher tier only: calculate the volumes of gases involved in reactions using the molar gas volume at room temperature and pressure, assumed to be 24 dm3. | M1b, M1c | |||
| C5.1f | Explain how the mass of a solute and the volume of the solution is related to the concentration of the solution. | M1b, M1c | WS1.3c, WS1.4a, WS1.4c | ||
| C5.1g | Higher tier only: calculate the theoretical mass of a product from a given mass of reactant. | M1a, M1c, M1d | WS1.3c | ||
| C5.1h | Higher tier only: calculate the percentage yield of a reaction product from the actual yield of a reaction. | M1a, M1c, M1d | WS1.2a, WS1.2b, WS1.2c, WS1.2d, WS1.3c, WS2a, WS2b | ||
| C5.1i | Higher tier only: define the atom economy of a reaction. | ||||
| C5.1j | Higher tier only: calculate the atom economy of a reaction to form a desired product from the balanced equation. | M1a, M1c | WS1.3c | ||
| C5.1k | Higher tier only: explain why a particular reaction pathway is chosen to produce a specified product given appropriate data. | Data such as atom economy, yield, rate, equilibrium position and usefulness of by-products. | M3b, M3c | WS1.3c, WS1.3f | |
| C5.2a | Suggest practical methods for determining the rate of a given reaction. | M1a, M1c | WS1.2b, WS1.2c, WS1.2d, WS2a, WS2b | Rate of reaction experiments: disappearing cross, magnesium and acid, marble chips and acid. (PAG C1, PAG C8) | |
| C5.2b | Interpret rate of reaction graphs. | 1/t is proportional to rate and gradients of graphs; order of reaction is not required. | M4b, M4c | WS1.3a, WS1.3b, WS1.3c, WS1.3d, WS1.3e, WS1.3f, WS1.3g, WS1.3h, WS1.3i, WS2b | Marble chips and acid or magnesium and acid experiments measuring reaction time or gas volume over time. (PAG C1, PAG C7, PAG C8) |
| C5.2c | Describe the effect of changes in temperature, concentration, pressure and surface area on rate of reaction. | M4d, M4e | WS1.4c | Vary surface area using marble chips and hydrochloric acid. (PAG C1, PAG C8) | |
| C5.2d | Explain the effects on rates of reaction of changes in temperature, concentration and pressure in terms of frequency and energy of collision between particles. | WS1.4c | React magnesium and acid at different acid temperatures and measure reaction times. (PAG C1, PAG C8) | ||
| C5.2e | Explain the effects on rates of reaction of changes in the size of pieces of a reacting solid in terms of surface area to volume ratio. | M1c | |||
| C5.2f | Describe the characteristics of catalysts and their effect on rates of reaction. | ||||
| C5.2g | Identify catalysts in reactions. | WS1.4a | Catalyse hydrogen peroxide with black powders including MnO2; catalyse zinc and sulfuric acid using copper powder. (PAG C1, PAG C8) | ||
| C5.2h | Explain catalytic action in terms of activation energy. | Reaction profiles. | |||
| C5.2i | Recall that enzymes act as catalysts in biological systems. | ||||
| C5.3a | Recall that some reactions may be reversed by altering the reaction conditions. | M1a, M4b, M4c | |||
| C5.3b | Recall that dynamic equilibrium occurs in a closed system when the rates of forward and reverse reactions are equal. | M4b, M4c | |||
| C5.3c | Predict the effect of changing reaction conditions on equilibrium position and suggest appropriate conditions to produce as much of a particular product as possible. | Le Chatelier's principle concerning concentration, temperature and pressure. | M1a, M4d, M4e, M1c | WS1.2a, WS1.2b, WS1.2c, WS1.4c, WS2a, WS2b |
Topic C6: Global challenges
| Reference | Learning outcomes | To include | Maths | Working scientifically | Practical suggestions |
|---|---|---|---|---|---|
| C6.1a | Explain, using the position of carbon in the reactivity series, the principles of industrial processes used to extract metals, including extraction of a non-ferrous metal. | Principles of using carbon to extract iron and other metals from their ores. | M1a, M1c | WS1.4a | Extract copper by heating copper oxide with carbon. (PAG C1) |
| C6.1b | Explain why and how electrolysis is used to extract some metals from their ores. | M4b, M4c | WS1.3a, WS1.3b, WS1.3c, WS1.3d, WS1.3e, WS1.3g, WS1.3h, WS1.3i, WS1.4, WS2b | Electrolysis of aqueous sodium chloride solution and aqueous copper sulfate solution. (PAG C2) | |
| C6.1c | Evaluate alternative biological methods of metal extraction. | Bacterial and phytoextraction. | WS1.1a, WS1.1e | ||
| C6.1d | Higher tier only: explain the trade-off between rate of production of a desired product and position of equilibrium in industrially important processes. | Haber process and Contact process. | M4d, M4e | WS1.3f | |
| C6.1e | Higher tier only: interpret graphs of reaction conditions versus rate. | M1c | WS1.3e | ||
| C6.1f | Higher tier only: explain how the commercially used conditions for an industrial process relate to availability and cost of raw materials and energy supplies, control of equilibrium position and rate. | WS1.1d | |||
| C6.1g | Higher tier only: explain the importance of the Haber process in agricultural production. | WS1.4a | |||
| C6.1h | Higher tier only: compare the industrial production of fertilisers with laboratory syntheses of the same products. | WS1.2a, WS1.2b, WS1.2c, WS1.2d, WS1.2e, WS2a, WS2b | Prepare potassium sulfate or ammonium sulfate using a titration method. (PAG C6) | ||
| C6.1i | Higher tier only: recall the importance of nitrogen, phosphorus and potassium compounds in agricultural production. | WS1.4a | |||
| C6.1j | Higher tier only: describe the industrial production of fertilisers as several integrated processes using a variety of raw materials. | Ammonium nitrate and ammonium sulfate. | WS1.2a, WS1.2b, WS1.2c, WS1.2e, WS2a, WS2b | ||
| C6.1k | Describe the basic principles in carrying out a life-cycle assessment of a material or product. | Use of resources and environmental impact across making materials, product manufacture, use, transport and end-of-life disposal. | |||
| C6.1l | Interpret data from a life-cycle assessment of a material or product. | ||||
| C6.1m | Describe a process where a material or product is recycled for a different use and explain why this is viable. | WS1.1f, WS1.1g | |||
| C6.1n | Evaluate factors that affect decisions on recycling. | WS1.1f, WS1.1g | |||
| C6.1o | Higher tier only: describe the composition of some important alloys in relation to their properties and uses. | Steel, brass, bronze, solder and duralumin. | |||
| C6.1p | Higher tier only: describe the process of corrosion and the conditions which cause corrosion. | Iron and other metals. | |||
| C6.1q | Higher tier only: explain how mitigation of corrosion is achieved by creating a physical barrier to oxygen and water and by sacrificial protection. | ||||
| C6.1r | Higher tier only: compare quantitatively the physical properties of glass and clay ceramics, polymers, composites and metals. | ||||
| C6.1s | Higher tier only: explain how the properties of materials are related to their uses and select appropriate materials given details of the usage required. | WS1.1e, WS1.3f | |||
| C6.2a | Higher tier only: recognise functional groups and identify members of the same homologous series. | Homologous series of alkanes, alkenes, alcohols and carboxylic acids. | |||
| C6.2b | Higher tier only: name and draw the structural formulae, using fully displayed formulae, of the first four members of the straight chain alkanes, alkenes, alcohols and carboxylic acids. | M5b | WS1.4a | Use models. | |
| C6.2c | Higher tier only: predict formulae and structures of products of reactions of the first four and other given members of homologous series of alkanes, alkenes and alcohols. | Combustion; addition of bromine and hydrogen across a double bond; oxidation of alcohols to carboxylic acids using potassium manganate(VII). | |||
| C6.2d | Higher tier only: recall the basic principles of addition polymerisation by reference to the functional group in the monomer and repeating units in the polymer. | ||||
| C6.2e | Higher tier only: explain the basic principles of condensation polymerisation. | Functional groups of monomers, minimum number of functional groups in a monomer, number of repeating units in the polymer, and simultaneous formation of a small molecule such as in a polyester or polyamide; use block diagrams to represent polymers. | WS1.4a | ||
| C6.2f | Higher tier only: describe practical techniques to make a polymer by condensation. | WS1.2a, WS1.2b, WS1.2c, WS1.4a, WS2a, WS2b | Make nylon. | ||
| C6.2g | Higher tier only: deduce the structure of an addition polymer from a simple alkene monomer and vice versa. | Polymer representation using [repeat unit]n. | WS1.4a | ||
| C6.2h | Higher tier only: recall that DNA is a polymer made from four different monomers called nucleotides and that other important naturally occurring polymers are based on sugars and amino acids. | Names of the nucleotides. | WS1.4a | ||
| C6.2i | Higher tier only: recall that it is the generality of reactions of functional groups that determine the reactions of organic compounds. | WS1.4a | |||
| C6.2j | Describe the separation of crude oil by fractional distillation. | Names of the fractions. | WS1.3f, WS1.4a | ||
| C6.2k | Explain the separation of crude oil by fractional distillation. | Molecular size and intermolecular forces. | |||
| C6.2l | Describe the fractions as largely a mixture of compounds of formula CnH2n+2 which are members of the alkane homologous series. | WS1.4a | |||
| C6.2m | Recall that crude oil is a main source of hydrocarbons and is a feedstock for the petrochemical industry. | WS1.4a | |||
| C6.2n | Explain how modern life is crucially dependent upon hydrocarbons and recognise that crude oil is a finite resource. | WS1.1c, WS1.1f, WS1.1e, WS1.4a | |||
| C6.2o | Describe the production of materials that are more useful by cracking. | Conditions and reasons for cracking and some useful materials produced. | |||
| C6.2p | Higher tier only: recall that a chemical cell produces a potential difference until the reactants are used up. | ||||
| C6.2q | Higher tier only: evaluate the advantages and disadvantages of hydrogen/oxygen and other fuel cells for given uses. | Chemistry of the hydrogen/oxygen fuel cell. | WS1.1g, WS1.1i | ||
| C6.3a | Interpret evidence for how it is thought the atmosphere was originally formed. | Knowledge of how the composition of the atmosphere has changed over time. | M2c, M4a, M2h | WS1.3e | |
| C6.3b | Describe how it is thought an oxygen-rich atmosphere developed over time. | M2h | WS1.1a | ||
| C6.3c | Describe the greenhouse effect in terms of the interaction of radiation with matter within the atmosphere. | ||||
| C6.3d | Evaluate the evidence for additional anthropogenic causes of climate change and describe the uncertainties in the evidence base. | Correlation between change in atmospheric carbon dioxide concentration and consumption of fossil fuels. | M2c, M4a, M2h | ||
| C6.3e | Describe the potential effects of increased levels of carbon dioxide and methane on the Earth's climate and how these effects may be mitigated. | Consider scale, risk and environmental implications. | M2c, M4a, M2h | WS1.1f, WS1.1h | |
| C6.3f | Describe major sources of carbon monoxide, sulfur dioxide, oxides of nitrogen and particulates in the atmosphere and explain problems caused by increased amounts of these substances. | WS1.4a | |||
| C6.3g | Describe the principal methods for increasing the availability of potable water in terms of the separation techniques used. | Ease of treatment of waste, ground and salt water. |
Topic C7 Practical skills
Learners must complete practical work that supports at least 15% of the assessment. The practical activity groups below show the core apparatus, techniques, and chemistry activities expected across the course.
Centres may use alternative practical activities where they cover the same apparatus and techniques.
Practical Activity Groups
| Practical Activity Group | Apparatus and techniques | Example chemistry activity |
|---|---|---|
| C1: Reactivity trend | Safely use and handle gases, liquids and solids. Carry out controlled mixing of solutions and use practical techniques to explore chemical changes and products. | Use displacement reactions to identify the trend in reactivity of Group 7 elements. |
| C2: Electrolysis | Set up and use electrochemical cells. Use qualitative reagents and techniques including gas tests, flame tests, precipitations, and concentration work. | Electrolyse aqueous sodium chloride or copper sulfate and test the gases produced. |
| C3: Separation techniques | Use purification and separation methods including evaporation, filtration, crystallisation, chromatography, and distillation. | Use chromatography to identify the different dyes in an unknown ink. |
| C4: Distillation | Use heating devices and techniques safely, including Bunsen burners, water baths, and electrical heaters. Measure mass, time, temperature, and volume of liquids or gases. | Distil a mixture such as a coloured drink, hydrocarbon mixture, or ink sample. |
| C5: Identification of species | Use qualitative tests for unknown samples and reaction products, including gas tests, flame tests, precipitation tests, and heating techniques. | Identify an unknown compound using cation tests, anion tests, and flame tests. |
| C6: Titration | Conduct and monitor reactions, including pH changes and concentration determinations, using accurate volume measurements. | Use titration to find the concentration of a strong acid or alkali with a suitable indicator. |
| C7: Production of salts | Combine separation, purification, pH monitoring, safe handling, mixing, and heating techniques. | Prepare a pure, dry sample of a soluble salt. |
| C8: Measuring rates of reaction | Measure and observe changes during chemical reactions, including temperature change, gas production, colour change, and change in mass. | Investigate how surface area or concentration affects the rate of reaction between an acid and a carbonate. |