The solubility of copper (II) tetraoxosulphate (Iv) is 75g in 100g of water at 100°C…

The solubility of copper (II) tetraoxosulphate (Iv) is 75g in 100g of water at 100°C and 25g in 100g of water at 30°C. What mass of the salt would crystallize, if 50g of copper (II) tetraoxosulphate (VI) solution saturated at 100°C were cooled to 30°C ?

Correct Answer: Option D

Explanation

solute + solvent = solution
at 100_oC; 75g + 100g = 175g
at30_oC; (frac{25g}{50g}) + 100g = 125g
From 100_oC – 30_oC; 175g CuSO₄ ppt 50g
From 100_oC – 30_oC; 50g CuSO₄ ppt (frac{50 times 50}{175}) = 14.3