Question

Q1. in an experiment, 295 mg of copper is deposited when a current of 500 ma passes for 30 minutes. find the electrochemical equivalent of copper

Answer 1

According to Faraday's first law of Electrolysis,
W = E.I.t/96500
where,
W = weight of substance deposited
E = Equivalent mass
I = Current passed
t = Time for which the current is being passed
96500 = Faraday constant

Putting in the values,
0.295 = 0.5 × 30 × 60 × E / 96500
E = 31.6 gm equivalents.

Now E = Molar mass / valency factor
Pay attention to the relation and try to figure it out yourself using the definitions of molarity and normality.

31.6 = 63.5 / n
n = 2.0094

Actually, for practical purposes, n for Cu is equal to charge on it which is +2