How many electrons are lost and gained by 2 g of `Cl^(-)` ions and 1 g of `Zn^(2+)` ions as the result of electrolysis respectively ? (Cl = 35.5, Zn = 65)

Explanation

Number of equivalents of `Cl^(-)` ions `= ("weight")/("eq. wt.")`
`= (2)/(35.5)`
Number of equivalent of `Zn^(2+)` ions `= (1)/(65//2) = (2)/(65)`.
Now,1 mole (1F) of electric charge discharges 1 equivalent of matter.
Molar of electric charge involved in case of `Cl^(-) = (2)/(35.5)`
Mole of electric charge involved in case of `Zn^(2+) = (2)/(65)`.
As 1 mole of electric charge corresponds to Av. no. of electrons, thus, no. of electrons lost by `Cl^(-) = (2)/(35.5) xx 6.022 xx 10^(23)`
and no. of electrons gained by `Zn^(2+) = (2)/(65) xx 6.022 xx 10^(23)`.