Question

The number of electrons delivered at the cathode during electrolysis by a current of 1 ampere in 60 seconds is: (charge on an electron is $1.60\times {{10} ^{-19}}C$):
(A) $3.75\times {{10} ^ {20}}$
(B) $7.48\times {{10} ^ {23}}$
(C) $6\times {{10} ^ {23}}$
(D) $6\times {{10} ^ {20}}$

Answer 1

For calculating the number of electrons, we can use the formula: $Q=$ $ne$.
where $Q$ is the amount of electricity passed,
$n$ is the number of electrons liberated at the cathode,
$e$ is the charge on an electron,

Complete step by step solution:
We have been provided with charge on an electron: $1.60\times {{10} ^ {-19}}C$,
Also, during electrolysis current is: 1 ampere and time: 60seconds,
We need to find the number of electrons,
So, for that we will be using the formula: $Q=$ $ne$,
Where Q is the amount of electricity passed,
n is the number of electrons liberated at cathode,
e is the charge on an electron,
we have been given e in the question that is equal to: $1.60\times {{10} ^ {-19}}C$,
so, we will be calculating Q,
so, the formula for calculating the amount of electricity passed is: $Q=i\times t$,
so, we can keep this value of Q in: Q=ne,
Now, the equation becomes: $i\times t=n\times e$,
So, the number of electrons liberated at cathode: $n=\dfrac {i\times t} {e}$,
Now, keeping the values in the above equation we would get: $n=\dfrac {1\times 60} {1.6\times {{10} ^ {-19}}}$,
So, the number of electrons comes out to be: $3.75\times {{10} ^ {20}}$.

Therefore, we can conclude that option (A) is correct.

Note: A cathode is a metallic electrode through which current flows out in a polarized electrical device. Conversely, an anode is an electrode in a polarized electrical device through which current flows in from an outside circuit.