Given:

Number of moles = 0.5

Atomic mass of N = 14 u

Atomic mass of N₂ = 2 × Atomic mass of N

= 2 × 14 u

= 28 u

Molar mass of N₂ = 28g/mol

To calculate the mass, apply the formula:

We can write:

Mass (m) = Number of moles (n) × Molar mass (M)

Mass = 0.5 mol × 28g/mol

Mass = 14g

Thus, the mass of 0.5 mole of N₂ gas is 14g