Explain why a hot saturated solution of potassium nitrate forms crystals as it cools.

Q. Pragya tested the solubility of three different substances at different temperatures and collected the data as given below(results are given in the following table, as grams of substance dissolved in $100$grams of water to form a saturated solution).

Q. Prachi makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.

Q. The weight of an empty china dish is 39 g and when a saturated solution of potassium nitrate is poured into, its weight is 108 g at ${50}^{\circ }C$. After evaporating the solution to dryness, if the weight of the dish along with the crystals is 72 g then the solubility of potassium nitrate at ${50}^{\circ }C$ is .....................

Q. Assertion :A super-saturated solution of glucose in boiling water crystallizes as it cools. Reason: The solubility increases as the temperature decreases.