C3 Topic 4 CM3.4i - arithmetic computation and ratio when Electrolysis is traditionally demonstrated with , although is a safer alternative. Decomposition of a liquid during the determining empirical formulae, balancing conduction of electricity is a chemical 4 hours OCR have Topic Exploration pack on electrolysis ( and ) containing guidance on equations [M1a, M1c] reaction called electrolysis. This section teaching and other suggested activities. The can also be of use. (separate and explores the electrolysis of various molten C3.4a - recall that metals (or hydrogen) are combined) can be carried out qualitatively, or extended to a quantitative investigation, ionic liquids and aqueous ionic solutions. formed at the cathode and non-metals are looking at the link between current and mass of copper sulfate deposited on the formed at the anode in electrolysis using inert Learners should be familiar with ionic cathode. While making accurate measurements can be challenging, this would electrodes [the terms cations and anions] solutions and solids. provide an opportunity to develop/refine pupils’ manipulative skills. C3.4b - predict the products of electrolysis of A common misconception is that ionic Competing reactions under electrolysis can be challenging for learners may – binary ionic compounds in the molten state solutions conduct because of the movement help, along with making the conceptual link between electrolysis as ‘normal’ [compounds such as NaCl] of electrons. Another common misconception chemical reaction in reverse, linking with reactivity series (e.g. reactivity series is that ionic solids do not conduct electricity C3.4c - describe competing reactions in the of metals, reactivity trends in Group 7). because electrons cannot move. electrolysis of aqueous solutions of ionic Spending time on ensuring a firm understanding of the terminology is useful – compounds in terms of the different species mind/concept can be useful as a learning tool as well as for revision. present [the electrolysis of aqueous NaCl and Demonstration of the electrolysis of dilute sulfuric acid to produce oxygen and CuSO4 using inert electrodes] hydrogen with a , links to research on the uses of products of electrolysis C3.4d - describe electrolysis in terms of the (online and offline) and makes a good project/homework. ions present and reactions at the electrodes C3.4e - describe the technique of electrolysis using inert and non-inert electrodes
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.
307972-topic-c3-suggested-teaching-hours-and-outline-scheme-of-work.docx