Question

The number of moles of electrons passed when a current of $2$ A is passed through a solution of electrolyte for $20$ minutes is:

• A. $4.1\times {10}^{-4}$ mole
• B. $1.24\times {10}^{-2}$ mole
• C. $2.487\times {10}^{-2}$ mole
• D. $2.487\times {10}^{-1}$ mole

Answer 1

The correct option is C $2.487\times {10}^{-2}$ mole

Current passed, $I=2A$

Time for which current is passed $t=20min=20min\times 60sec/min=1200s$

So, total charge flown, $Q=It=2A\times 1200s=2400C$

Number of moles of electrons $n=\frac{Q}{96500}=\frac{2400C}{96500C/mol{e}^{-}}=2.487\times {10}^{-2}$ moles

Hence, option $C$ is correct.