Question

Calculate the total number of electrons present in 1.4 gm of nitrogen gas

Answer 1

Number of moles in the given weight of Nitrogen gas $\left(N_2\right)$ .
Number of moles = Given weight/molecular weight
= 1.4/28
=0.05 moles
1 mole of Nitrogen contains the Avogadro number ($6.023\times {10}^{23}$ ) of Nitrogen molecules.
0.05 moles of Nitrogen contains = $0.05\times 6.023\times {10}^{23}$
= $3.011\times {10}^{22}$ molecules
1 molecule of Nitrogen contains 14 electrons

$3.011\times {10}^{22}$ molecules contains = $3.011\times {10}^{22}$ $\times 14$
= 42.154$\times {10}^{22}$
= 4.215$\times {10}^{23}$ number of electrons.