Question

Calculate the % of oxygen in Al₂(SO₄)₃. (Atomic mass: Al-27, O-16, S -32)

Answer 1

Aluminum Sulphate – Al₂(SO₄)₃

Molar mass of Aluminium Sulphate = (27 × 2) + (32 × 3) + (16 × 12) = 54 + 96 + 192 = 342 g

% of Oxygen = `192/342 × 100` = 56.14%.