Question

Assertion A: A saturated solution is that solution which can dissolve any more of solute only on heating. Reason R: If a saturated solution is cooled some of the solute can be seen at the bottom of the container. A) Both A and R are true and R is the correct explanation of A. B) Both A and R are true but R is not the correct explanation of A. C) A is true but R is false. D) A is false but R is true.​

Answer 1

Answer:

Correct option is

C

Assertion is correct but Reason is not correct.

Supersaturation is a state of a solution that contains more of the dissolved material than could be dissolved by the solvent under normal circumstances.

As a general rule, the more heat is added to a system, the more soluble a substance becomes. (There are exceptions where the opposite is true). Therefore, at high temperatures, more solute can be dissolved than at room temperature. If this solution were to be suddenly cooled at a rate faster than the rate of precipitation, the solution will become supersaturated until the solute precipitates to the temperature-determined saturation point. The precipitation or crystallization of the solute takes longer than the actual cooling time because the molecules need to meet up and form the precipitate without being knocked apart by water.

So, both the Assertion and Reason are correct and Reason is not the correct explanation of Assertion.