Question

A solution of $CuS{O}_4$ is electrolyzed for $10$ minutes with a current of $1.5A$. What is the mass of copper deposited at the cathode?

[Atomic weight of copper = $63$]

• A. $0.29$ gm
• B. $0.35$ gm
• C. $0.0048$ gm
• D. $0.7$ gm

Answer 1

Answer: (A)

$0.29$ gm

From faraday's law of electrolysis,

$m=\left(\frac{It}{F}\right)\times \left(\frac{M}{Z}\right)$

m = Mass deposited at the electrode

I = Current passing through $=1.5$ A

t = Time $=10\times 60$ seconds $=600$ seconds

Z = Valency number of ions of the substance (electrons transferred per ion) =2

F = Faraday constant

M = Molecular weight

Mass deposited is $=\left(\frac{600\times 1.5}{96500}\right)\times \left(\frac{63}{2}\right)$

$=0.293$ grams