Question
The number of electrons delivered at the cathode during electrolysis by a current of $${\text{1 ampere}}$$ in 60 seconds is ( charge on electron $${\text{ = 1}}{\text{.60}} \times {\text{1}}{{\text{0}}^{ - 19}}C$$ )
A.
$$6 \times {10^{23}}$$
B.
$$6 \times {10^{20}}$$
C.
$$3.75 \times {10^{20}}$$
D.
$$7.48 \times {10^{23}}$$
Answer :
$$3.75 \times {10^{20}}$$
Solution :
$$\eqalign{
& {\text{From Faraday's}}\,{\text{first law of electrolysis,}} \cr
& \frac{w}{E} = \frac{{it}}{{96500}}\,\,\,...{\text{(i)}} \cr
& {\text{Given,}}\,i = 1\,A;\,t = 60\,s \cr
& {\text{Putting these values in Eq}}.{\text{(i), we get}} \cr
& \frac{w}{E} = \frac{{1 \times 60}}{{96500}}\,\,{\text{or}}\,\,\frac{w}{E} = \frac{6}{{9650}} \cr
& = {\text{Number of mole of electrons}} \cr
& \therefore \,\,{\text{Number of electrons}} \cr
& = \frac{6}{{9650}} \times 6.022 \times {10^{23}} \cr
& = 3.75 \times {10^{20}} \cr} $$