Which among following salts shows decrease in solubility with increase in temperature?
Which among following salts shows decrease in solubility with increase in temperature?
$\mathrm{Na}_2 \mathrm{SO}_4$
$\mathrm{KNO}_3$
$\mathrm{NaNO}_3$
$\mathrm{KBr}$
Solution
Dissolution of $\mathrm{Na}_2 \mathrm{SO}_4$ in water is an exothermic process. When a substance dissolves in water by an exothermic process, its solubility decreases with an increase in temperature. Hence, solubility of $\mathrm{Na}_2 \mathrm{SO}_4$ in water decreases with increase in temperature.