Question

2g of potassium sulphate was dissolved in 12.5 ml of water. On cooling, the first crystals appeared at ${60}^{\circ }C$. The solubility of potassium sulphate in water at ${60}^{\circ }C$ is __ g.

Answer 1

12.5 ml of water weighs 12.5g.

In 12.5g of water, the amount of potassium sulphate dissolved is 2g.

In 1g of water, the amount of potassium sulphate dissolved is$\frac{2}{12.5}g$ .

Hence in 100g of water, the amount of potassium sulphate dissolved is$\frac{2}{12.5}\times 100\Rightarrow 16g$

The solubility of potassium sulphate in water at ${60}^{\circ }C$ is 16g.