Question

In a saturated solution with endothermic dissolution, how does the concentration of dissolved solute change with increasing then decreasing temperature?

(a) Keeps increasing

(b) Keeps decreasing

(c) Increases and decreases

(d) Decreases and increases

This question was posed to me in an interview.

The question is from Solubility Solutions in division Solutions of Chemistry – Class 12

Answer 1

Right answer is (d) Decreases and increases

For explanation I would say: When a solution is saturated a thermodynamic equilibrium exists between the undissolved solute and dissolved solute. Since the dissolution process here is mentioned as endothermic increasing and decreasing temperatures will decrease and increase the concentration, respectively, as given by Le Chatelier’s Principle of equilibrium.