The electrochemical equivalent of a metal is 3.3 × 10–7kg per coulomb. The mass of the metal liberated at the cathode when a 3A current is passed for 2 second will be
(a) 19.8 × 10–7kg
(b) 9.9 × 10–7kg
(c) 6.6 × 10–7kg
(d) 1.1 × 10–7kg.
Correct Option(a) 19.8 × 10–7kg
Explanation:
Mass of substance liberated at cathode
m= zlt
where, z = electro-chemical equivalent
= 3.3 x 10-7 kg C-1
I = Current flowing =3A
t=2s
So, m=3.3 x 10-7 x 3 x2
=19.8 x 10-7 kg
