Question

100 ml solution of silver positive is electrolyzed for 15 minutes with the current of 1.25 milliampere and silver is removed completely. what was initial silver?

• A. $2.32\times {10}^{-1}$
• B. $2.32\times {10}^{-4}$
• C. $2.32\times {10}^{-3}$
• D. $1.16\times {10}^{-4}$

Answer 1

The correct option is D $1.16\times {10}^{-4}$

Given ,

v = 100 mL

t = 15 min

I = 1.25 A

As we know,

Q = It

$\Rightarrow$ Q = $1.25\times {10}^{-3}\times 15\times 60$ = 1.125 C

Cathodic reaction

$A{g}^{+}+e^{-}\to Ag$

1F 108gm

$\Rightarrow$ 96500 C $\to$ 108 gm

$\Rightarrow$ 1.125 C $\to \frac{108\times 1.125}{96500}$

$\Rightarrow 1.259\times {10}^{-3}$ gm

conc. of $A{g}^{+}=\frac{1.259\times {10}^{-3}\times {10}^3}{108\times 100}=1.16\times {10}^{-4}$

Hence , option D is correct .