electrodes. Positively Explain what happens to charged ions move to the positive and negative ions negative electrode (the during electrolysis and how cathode), and negatively elements form from charged ions move to the ions. positive electrode (the anode). Ions are discharged at the electrodes producing elements. This process is called electrolysis. 5.4.3.2 When a simple ionic Students should be able 0.5 Calculate the atom Demo the electrolysis of Video clip: compound (eg lead bromide) to predict the products economy for simple lead bromide. A safer YouTube: is electrolysed in the molten of the electrolysis of examples. alternative for practical work state using inert electrodes, binary ionic compounds is anhydrous zinc chloride. the metal (lead) is produced in the molten state. Extended writing: write at the cathode and the instructions to another Write balanced half (bromine) is produced student how to calculate equations for the reactions at the anode. the atom economy giving that occur at both explained examples. electrodes. 5.4.3.3 Metals can be extracted from Explain why a mixture is 1 Recall the reactivity series. Research how aluminium is molten compounds using used as the electrolyte. extracted from its ore. electrolysis. Electrolysis is Give reasons why some Write balanced half used if the metal is too Explain why the positive metals have to be extracted equations for the reactions reactive to be extracted by electrode must be by electrolysis. that occur at both reduction with carbon or if continually replaced. electrodes. the metal reacts with carbon. Extended writing: describe Large amounts of energy are WS 1.4, 4.1 how aluminium is extracted used in the extraction from its ore. process to melt the compounds and to produce Write balanced half the electrical current. equations for the reactions
electrodes. Positively charged ions move to the negative electrode (the cathode), and negatively charged ions move to the positive electrode (the anode). Ions are discharged at the electrodes producing elements. This process is called electrolysis. Explain what happens to positive and negative ions during electrolysis and how elements form from ions. 5.4.3.2 When a simple ionic compound (eg lead bromide) is electrolysed in the molten state using inert electrodes, the metal (lead) is produced at the cathode and the (bromine) is produced at the anode. Students should be able to predict the products of the electrolysis of binary ionic compounds in the molten state. 0.5 Calculate the atom economy for simple examples. Extended writing: write instructions to another student how to calculate the atom economy giving explained examples. Demo the electrolysis of lead bromide. A safer alternative for practical work is anhydrous zinc chloride. Write balanced half equations for the reactions that occur at both electrodes. Video clip: YouTube: 5.4.3.3 Metals can be extracted from molten compounds using electrolysis. Electrolysis is used if the metal is too reactive to be extracted by reduction with carbon or if the metal reacts with carbon. Large amounts of energy are used in the extraction process to melt the compounds and to produce the electrical current. Explain why a mixture is used as the electrolyte. Explain why the positive electrode must be continually replaced. WS 1.4, 4.1 1 Recall the reactivity series. Give reasons why some metals have to be extracted by electrolysis. Extended writing: describe how aluminium is extracted from its ore. Write balanced half equations for the reactions Research how aluminium is extracted from its ore. Write balanced half equations for the reactions that occur at both electrodes.
AQA-8464-SOW-CCHG.DOCX