Q. The electro chemical equivalent of metal is $3.3 \times 10^{- 7}kgC^{- 1}$. The mass of the metal liberated at the cathode when a 3 A current is passed for 2 s, will be
A) $19.8 \times 10^{- 7}\ kg$
B) 9.9 $\times 10^{- 7}\ kg$
C) 6.6 $\times 10^{- 7}\ kg$
D) 1.1 $\times 10^{- 7}\ kg$
Explanation
(a) Mass of substance liberated at cathode $m = zit$
Where, $z =$ electro chemical equivalent
$= \ 3.3 \times 10^{- 7}kg\ .C^{- 1}$
$\ i =$ current flowing = 3 A,
$\ t = 2$s
$m = 3.3 \times 10^{- 7} \times 3 \times 2$
$\ = 19.8 \times 10^{7}$ kg
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.