Given:

Mass of dinitrogen = 1.4 g

We know that molar mass of dinitrogen = 28 g mol^-1

∴ The number of moles of dinitrogen in 1.4g = 1.4/28 = 0.05mol

Now, the number of molecules in 1.4g of dinitrogen: -

= 0.05 x 6.022 × 10²³

= 3.01 x 10²³

We know that 1 molecule of dinitrogen contains 14 electrons.

∴ 3.01 × 10²³ molecules of dinitrogen contain:

= 14 × 3.01 × 1023

= 4.214 × 10²³ electrons.

Hence, the total number of electrons present in 1.4 g of dinitrogen gas is 4.214 × 10²³.