A mixture of 100 m mol of Ca(OH)₂ and 2 g of sodium sulphate was dissolved in water and the volume was made up to 100 mL. The mass of calcium sulphate formed and the concentration of OH^– in resulting solution, respectively, are : (Molar mass of Ca (OH)₂, Na₂SO₄ and CaSO₄ are 74, 143 and 136 g mol^–1
, respectively; K_sp of Ca(OH)₂ is 5.5 × 10^–6
)