What is the mass of
(a) 1 mole of nitrogen atoms?
(b) 4 moles of aluminium atoms (Atomic mass of aluminium = 27)?
(c) 10 moles of sodium sulphite (Na₂S0₃)?

(a) Mass of 1 mole of nitrogen atoms = 14 g

(b) 4 moles of aluminium atoms

Mass of 1 mole of aluminium atoms = 27 g

∴ Mass of 4 moles of aluminium atoms = 27 x 4 = 108 g

(c) 10 moles of sodium sulphite (Na₂SO₃)

Mass of 1 mole of Na₂SO₃ = 2 x 23 + 32 + 3 x 16 = 46 + 32 + 48 = 126 g

∴ Mass of 10 moles of Na₂SO₃ = 126 x 10 = 1260 g.

[Extra information: Molar mass is defined as the mass of a substance for a given amount where the amount of the substance refers to the number of molecules or atoms or compounds present in one mole of a substance. The SI unit of the Molar mass of a substance is always caculated in is g/mol.]