passwella.
Menu

JAMB Chemistry 1998 Question 23

Question 23

Electrolysis

What mass of gold is deposited during the electrolysis of gold (III) tetraoxosulphate (VI) when a current of 15A is passed for 193 seconds? [Au = 97, F = 96500C mol−1].

  1. A.1.97g
  2. B.3.94g
  3. C.5.91 g
  4. D.19.70 g
Show the answer and explanation

Answer: A (1.97g)

Explanation

Q = 15 × 193 = 2895 C = 0.03 F. Au3+ needs 3 F per mole, so 0.01 mol of gold is deposited. With the true Au = 197 this is 1.97 g.