The electrolytic cell below is set up to obtain pure copper from a piece of impure copper.
The impure copper contains other metals, such as platinum, iron, cobalt, silver and nickel.
The cell potential of the power source is adjusted so that only copper is deposited on electrode B.
9.1 Define an electrolytic cell. (2)
9.2 Write down the FORMULA of a suitable electrolyte for this cell. (1)
9.3 Which electrode (A or B) is the cathode? Write down the relevant half-reaction taking place at this electrode. (3)
9.4 Sludge forms below one of the electrodes while the cell above is in operation. Which of the metals, PLATINUM, IRON, COBALT, SILVER or NICKEL, will be present in the sludge? (2)
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