Two voltameters, one of copper and another of silver, are joined in parallel. When a total charge q flows through the voltameters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are `Z_1` and `Z_2` respectively the charge which flows through the silver voltameter is

Options

A. `q/(1+ Z_2/Z_1)`
B. `q/(1+Z_1/Z_2)`
C. `q(Z_2/Z_1)`
D. `q(Z_1/Z_2)`

Answer

A

Explanation

(a) Mass deposited
`m = Zq rArr Z prop 1/q rArr Z_1/Z_2 = q_2/q_1`………..(i)
Also `q = q_1+q_2` ………(ii)
`rArr q/q_2 = q_1/q_2 + 1` (dividing (ii) by `q_2`)
`rArr q_2 = q/(1+q_1/q_2) ……….(iii)
From equations (i) and (iii), `q_2 = 1/(1+ Z_2/Z_1)`.