(solved)Question 2.1 of NCERT Class XI Chemistry Chapter 2

$\displaystyle \underline{\underline{\text{Part (i)}}}$

Mass of 1 electron = $\displaystyle 9.1 \times 10^{-31} $ kg

i.e., = $\displaystyle 9.1 \times 10^{-31} \times 1000 \text{ grams}$

i.e., = $\displaystyle 9.1 \times 10^{-28} \text{ grams}$

by unitary $\displaystyle 9.1 \times 10^{-28} \text{ g} \equiv $ 1 electron

$\displaystyle \implies 1 \text{ g} \equiv \frac{1}{9.1 \times 10^{-28}}$ electrons

$\displaystyle = 1.099 \times 10^{27} \text{ electrons}\:\underline{Ans}$

$\displaystyle \underline{\underline{\text{Part (ii)}}}$

1 mol electron = $\displaystyle 6.023 \times 10^{23}$ electrons

Mass of 1 electron = $\displaystyle 9.1 \times 10^{-31} $ kg

∴ of 1 mol = $\displaystyle 9.1 \times 10^{-31} \times (6.023 \times 10^{23})$ kg

= $\displaystyle 5.48 \times 10^{-7} \text{ kg} \:\underline{Ans}$

Charge on 1 electron = $\displaystyle 1.6 \times 10^{-19} \text{ C}$

∴ of 1 mol = $\displaystyle 1.6 \times 10^{-19} \times (6.023 \times 10^{23})$ C

= $\displaystyle 9.64 \times 10^{4} \text{ C} \:\underline{Ans}$