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JAMB Chemistry 1985 Question 17

Question 17

Electrolysis

Copper sulphate solution is electrolysed using platinum electrodes. A current of 0.193 amperes is passed for 2 hrs. How many grams of copper are deposited? (Cu = 63.5, F = 96500 coulombs).

  1. A.0.457 g
  2. B.0.500 g
  3. C.0.882 g
  4. D.0.914 g
  5. E.1.000 g.
Show the answer and explanation

Answer: A (0.457 g)

Explanation

Charge = 0.193 × 2 × 3600 = 1389.6 C. Cu2+ needs 2 × 96500 C per mole (63.5 g), so mass = 63.5 × 1389.6 / 193000 = 0.457 g.