metals. PAG C1, C7, C8: Reaction of metals with water, dilute hydrochloric acid. PAG C1, C7, C8: Displacement reactions involving metals and metal salts. C4.2 – Identifying the products of chemical reactions 8 / 1 PAG C5: Flame tests. PAG C5: Testing unknown solutions for cations and anions. PAG C5: Tests for anions using silver nitrate and barium sulfate. PAG C5: Tests for cations using sodium hydroxide. Total 16 / 7 Topics Suggested teaching hours Separate / Combined Comments and PAG opportunities Topic C5: Monitoring and controlling chemical reactions C5.1 – Monitoring chemical reactions 12 / 1 PAG C6: Acid/alkali titrations. PAG C8: Measurement of gas volumes and calculating amount in moles. C5.2 – Controlling reactions 10 / 10 PAG C1, C7, C8: Marble chip and acid or magnesium and acid experiments either measuring reaction time or the volume of gas over time. PAG C1, C8: Catalysis of hydrogen peroxide with various black powders including MnO2. PAG C1, C8: Catalysis of reaction of zinc with sulfuric acid using copper powder. PAG C1, C8: Magnesium and acid, marble chip and acid. PAG C1, C8: Rate of reaction experiments. PAG C1, C8: Reaction of magnesium and acid with different temperatures of acid – measure reaction times. PAG C1, C8: Varying surface area with marble chips and hydrochloric acid. PAG C8: Disappearing cross experiment. C5.3 – Equilibria 3 / 3 Total 25 / 14 Topic C6: Global challenges C6.1 – Improving processes and products 16 / 7 PAG C1: Extraction of copper by heating copper oxide with carbon. PAG C2: Electrolysis of aqueous copper sulfate solution. PAG C2: Electrolysis of aqueous sodium chloride solution. PAG C6: Preparation of potassium sulfate or ammonium sulfate using a titration method. C6.2 – Organic chemistry 12 / 4 C6.3 – Interpreting and interacting with earth systems 8 / 7 Total 36 / 18 GRAND TOTAL SUGGESTED HOURS – 140 / 98 hours This symbol indicates content that is found only in the chemistry separate science qualification.
Outline Scheme of Work: C3 – Chemical reactions Total suggested teaching time – 31 hours (separate and combined) C3.1 – Introducing chemical reactions (11 hours – separate and combined) Links to KS3 Subject content chemical reactions as the rearrangement of atoms chemical symbols and formulae for elements and compounds conservation of mass changes of state and chemical reactions. energy changes on changes of state (qualitative) representing chemical reactions using formulae and using equations the Periodic Table: periods and groups; metals and non-metals thermal decomposition Links to Practical Activity Groups (PAGs) N/A Links to Mathematical Skills M1a M1b M1c M2a Links to Working Scientifically WS1.1b WS1.3c WS1.4a WS1.4b WS1.4c WS1.4d WS1.4f
C3 Topic 4 4 hours (separate and combined) CM3.4i - arithmetic computation and ratio when determining empirical formulae, balancing equations [M1a, M1c] 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] C3.4b - predict the products of electrolysis of binary ionic compounds in the molten state [compounds such as NaCl] C3.4c - describe competing reactions in the electrolysis of aqueous solutions of ionic compounds in terms of the different species present [the electrolysis of aqueous NaCl and CuSO4 using inert electrodes] C3.4d - describe electrolysis in terms of the ions present and reactions at the electrodes C3.4e - describe the technique of electrolysis using inert and non-inert electrodes Electrolysis is traditionally demonstrated with , although is a safer alternative. OCR have Topic Exploration pack on electrolysis ( and ) containing guidance on teaching and other suggested activities. The can also be of use. can be carried out qualitatively, or extended to a quantitative investigation, looking at the link between current and mass of copper sulfate deposited on the cathode. While making accurate measurements can be challenging, this would provide an opportunity to develop/refine pupils’ manipulative skills. Competing reactions under electrolysis can be challenging for learners – may help, along with making the conceptual link between electrolysis as ‘normal’ chemical reaction in reverse, linking with reactivity series (e.g. reactivity series of metals, reactivity trends in Group 7). Spending time on ensuring a firm understanding of the terminology is useful – mind/concept can be useful as a learning tool as well as for revision. Demonstration of the electrolysis of dilute sulfuric acid to produce oxygen and hydrogen with a , links to research on the uses of products of electrolysis (online and offline) and makes a good project/homework. Decomposition of a liquid during the conduction of electricity is a chemical reaction called electrolysis. This section explores the electrolysis of various molten ionic liquids and aqueous ionic solutions. Learners should be familiar with ionic solutions and solids. A common misconception is that ionic solutions conduct because of the movement of electrons. Another common misconception is that ionic solids do not conduct electricity because electrons cannot move.