Read the following passage and answer the questions that follow : An electrochemical process is used for…
Read the following passage and answer the questions that follow :
An electrochemical process is used for refining metals by selectively dissolving and depositing them through electrolysis. Electrolytic refining is used for metals like Copper, Zinc, Tin, Nickel, Silver and Gold.
(a) Define anode mud.
(b) In electrolytic refining of copper, name the anode and the cathode.
(c) (i) With the help of chemical equations, show the extraction of copper from its ore Cu2S.
Solution
(a) During electrolytic refining of a metal, the insoluble impurities
which settle down at the bottom of the anode is called anode mud.
(b) Anode: Impure copper rod
Cathode: Pure copper strip
heat
(c) (i) 2Cu2 S + 3O2 (g) → 2Cu2 O (s) + 2SO2 (g)
heat
2Cu2 O + Cu2 S → 6Cu(s) + SO2 (g)
OR
(c) (ii)
(Diagram- 1 mark, Labelling-1 mark)
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