20 grams of a gas M 2 P has lesser number of moles than 20 grams of the gas MP.

Molecular mass of M₂P = 2(14) + 16 = 44 g/mol

Molecular mass of MP = 14 + 16 = 30 g/mol

Number of moles = $\frac{\text{Mass}}{\text{Molecular mass}}$

∴ Moles in 20 g of M₂P = $\frac{20}{44}$ = 0.45 mol

∴ Moles in 20 g of MP = $\frac{20}{30}$ = 0.67 mol

Since 0.45 < 0.67, 20 grams of M₂P has a lesser number of moles than 20 grams of MP. Hence, the statement is justified.