If 96500 coulombs of electricity liberates one gram equivalent of anysubstance, the time taken for a current of 0.15 amperes to deposite20mg of copper from a solution of copper sulphate is (Chemicalequivalent of copper = 32)
Correct option is B. 6 min 42 sec
It is known that mass deposited $$ M = Z it$$
$$ \Rightarrow M= 20 \times 10 ^{-3} = \left ( \dfrac{32}{96500} \right ) \times 0.15 \times t $$
= 6.7 min = 6 min 42 sec