Question

Calculate the mass of 0.5 mole of N₂ gas. 

[Atomic mass of N = 14 u]

Answer 1

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: 

Number of moles (n) = \(\frac{Mass\,(m)}{Molar\,mass\,(M)}\)

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