Question

Question 5.13 Calculate the total number of electrons present in 1.4 g of dinitrogen gas.

Class XI States of Matter Page 153

Answer 1

given mass of N2 = 1.4g
molar mass of N2 = 28g/mol

now, mole = given mass/molar mass
= 1.4/28 = 0.05 mol

hence, total number of N2 molecule = no of moles of N2 × Avogadro's number
= 0.05 × 6.022 × 10²³
= 3.011 × 10²² molecules

we know, 1 molecule of N2 = 14 electrons
so, 3.011 × 10²² molecules of N2 = 14 × 6.022 × 10²² electrons
= 4.2154 × 10²³ electrons