What is the molecular mass of nitrogen gas (N₂) if 11.2 dm³ of gas at STP equals 1 mole?

14 g

1.4 g

28 g

2.8 g

Explanation

At STP, 1 mole of any gas occupies 22.4 dm³.
If 11.2 dm³ = 0.5 mole →
0.5 mole of nitrogen (N₂) = 14 g
→ Full mole = 28 g (molecular mass of N₂)