If 0.500 mole of Na+ cations are available in aqueous solution, how many grams of Na2SO4 can form when the water is boiled off (assuming plenty of sulphate ions are available)?

Answer 1

0.500 moles Na⁺ x 1 mole Na₂SO₄/2 moles Na⁺ = 0.250 moles Na₂SO₄ can form

mass of Na₂SO₄ = 0.250 moles x 142 g/mole = 35.5 g of Na₂SO₄ can form