Question

What will be the atomicity of nitrogen if 14 g of nitrogen occupies 11.2 L at S.T.P.?

Answer 1

At S.T.P., 1 mole of any gas occupies 22.4 L.

Given:

Volume of nitrogen = 11.2 L

Mass of nitrogen = 14 g

Atomic mass of nitrogen = 14 u

Calculate moles of nitrogen:

Moles = `11.2/22.4` = 0.5 mol

So, 14 g of nitrogen is 0.5 mol.

Therefore, the molar mass of nitrogen:

`14/0.5` = 28 g mol⁻¹

Since the atomic mass of nitrogen is 14:

Atomicity = `28/14` ​= 2​

The atomicity of nitrogen is 2.

Thus, nitrogen exists as a diatomic molecule, N₂.