Question

A current of 4 amp was passed for 2 hours through a solution of copper sulphate when 5.0 g of copper was deposited. The current efficiency is ______% (Cu = 63.5).

Options

• 56.90

• 60.09

• 10.25

• 52.76

Answer 1

A current of 4 amp was passed for 2 hours through a solution of copper sulphate when 5.0 g of copper was deposited. The current efficiency is 52.76 %.

Explanation:

W = `"E"/96500 xx "i" xx "t"`

`"I"_"cal" = ("W" xx 96500)/("E" xx "t")`

`= (5 xx 96500 xx 2 xx 10)/(63.5 xx 2 xx 60 xx 60)`

= 2.11

Current efficiency = `"I"_"cal"/"I"_"given" xx 100`

`= 2.11/4 xx 100`

= 52.76 %