PRACTICE TEST 2– Redox AS913913, 3 credits 1 SRP QUESTION 1: Electrolysis of aqueous CuCl 2 Stephena sets up an electrolysis cell using copper chloride solution and carbon electrodes. She notices that bubbles of a colourless gas are produced at one electrode and a red-brown coating forms on the other electrode. Use the following E° values as well as your sheet: (H2O/H2) 0.00 V (H2O/O2) +1.23 V Draw a picture showing how aqueous copper chloride could be electrolysed with carbon electrodes. Decide what species gets oxidised and what species gets reduced and justify this decision with oxidation numbers or electron transfer Write balanced equations (half and full) for the reaction Calculate an E°cell and explain its significance Write what would be observed at each electrode and link to the species involved QUESTION 2: Electrochemical cell comparison Stephena now sets up an electrochemical cell as follows: in one half cell is a solution of copper ions and a copper electrode and in the other is a solution of gold ions and a gold electrode. Draw a cell diagram of the galvanic cell (optional) Decide what species gets oxidised and what species gets reduced and justify this decision with oxidation numbers or electron transfer Write balanced equations (half and full) for the reaction Calculate an E°cell and explain its significance Write what would be observed in each half cell and link to the species involved Finally: COMPARE and CONTRAST the two cells in terms of their spontaneity and energy changes.
PRACTICE TEST 2– Redox AS913913, 3 credits 1 SRP QUESTION 1: Electrolysis of aqueous CuCl 2 Stephena sets up an electrolysis cell using copper chloride solution and carbon electrodes. She notices that bubbles of a colourless gas are produced at one electrode and a red-brown coating forms on the other electrode. Use the following E° values as well as your sheet: (H2O/H2) 0.00 V (H2O/O2) +1.23 V Draw a picture showing how aqueous copper chloride could be electrolysed with carbon electrodes. Decide what species gets oxidised and what species gets reduced and justify this decision with oxidation numbers or electron transfer Write balanced equations (half and full) for the reaction Calculate an E°cell and explain its significance Write what would be observed at each electrode and link to the species involved QUESTION 2: Electrochemical cell comparison Stephena now sets up an electrochemical cell as follows: in one half cell is a solution of copper ions and a copper electrode and in the other is a solution of gold ions and a gold electrode. Draw a cell diagram of the galvanic cell (optional) Decide what species gets oxidised and what species gets reduced and justify this decision with oxidation numbers or electron transfer Write balanced equations (half and full) for the reaction Calculate an E°cell and explain its significance Write what would be observed in each half cell and link to the species involved Finally: COMPARE and CONTRAST the two cells in terms of their spontaneity and energy changes.
practice_test_2_comparison.docx