Question

Calculate the mass percent of different elements present in Sodium Sulphate (Na₂SO₄).

Answer 1

Molar mass of Na₂SO₄ = [(2 × 23.0) + (32.00) + 4 (16.00)] = 142 g

Mass percent of an element = (Mass of that element in compound/Molar mass of that compound) x 100

∴ Mass percent of sodium (Na): (46/142) x 100 = 32.39% 

Mass percent of sulphur(S): (32/142) x 100 = 22.54% 

Mass percent of oxygen:(O): (64/142) x 100 = 45.07%