What is the mass of 1 mole of nitrogen atoms?

(a) 1 mole of nitrogen atoms = 1 × mass of N = 1 × 14 = 14 g
(b) 4 moles of aluminium atoms = 4 × 27 = 108 g
(c) 10 moles of sodium sulphite (Na₂SO₃) = 10 × Mass of Na₂SO₃.
Mass of Na₂SO₃ = 2 × Mass of Na atom + 1 × Mass of S atom + 3 × Mass of O atom = 2 × 23 + 1 × 32 + 3 × 16 = 46 + 32 + 48 = 126 g/mol
∴ 10 moles of Na₂SO₃ = 10 × 126 = 1260 g