Q.

Mass in grams of copper deposited by passing 9.6487 A current through a voltmeter containing copper sulphate solution for 100 seconds is

(Given: Molar mass of Cu = 63 g mol-1, 1F = 96487 C)              [2024]

1 3.15 g  
2 0.315 g  
3 31.5 g  
4 0.0315 g  

Ans.

(2)

Given,

Current (I)=9.6487 A,  Time(t)=100 seconds

1F = 96487 C

Reaction : Cu(aq)2++2e-Cu(s)

Here, 2 electrons are exchanged, so valency factor (n)=2.

Applying Faraday’s first law, W=ZIt      (Z=Equivalent weightF=632×96487)

So, W=63×9.6487×1002×96487=0.315 g