Question

When electric current is passed through acidified water,112 mL of hydrogen gas at N.T.P. was collected at the cathode in 965 seconds.The current passed, in ampere, is:

• A. 1
• B. 0.5
• C. 0.1
• D. 2

Answer 1

The correct option is A 1

As we know that,

$22400ml$ of hydrogen = $1mole=2g$

So, $112ml$ of hydrogen contains = $\frac{2\times 112}{22400}={10}^{-2}g$

Now,

$2H^{+}+2e^{-}\to H_2$

By Faraday's Law

$nF=1mole$

So, $2g$ is deposited by $2\times 96500C$

$0.2g$ will be deposited by $\frac{2\times 96500\times {10}^{-2}}{2}=965C$

Current = $\frac{Charge}{time}=\frac{965C}{965s}=1A$

Thus, the current passed is $1A$