Question

What happens when an unsaturated solution of a solute is gradually cooled?

Answer 1

As the temperature of an unsaturated solution is lowered, at this lowered temperature the amount of solute dissolved in it makes a saturated solution.

• Imagine you start with solution A which is saturated.
• Now you increase the temperature of solution A and get a solution B which is now unsaturated at this higher temperature.
• As you lower the temperature, you go back to solution A which is saturated.
• Thus, when an unsaturated solution of a solute is gradually cooled you get a saturated solution.

Solubility: The amount of substance that can be dissolved in a given amount of solute at a fixed temperature.

• Solubility decreases with a decrease in temperature and increases with an increase in temperature.

Unsaturated solution: A solution in which more solute can be dissolved at a given temperature in the given amount of a solvent is known as an unsaturated solution.

Saturated solution: A solution that holds the maximum amount of solute in the given amount of solvent at a particular temperature is known as a saturated solution.

• Alternatively, when no more solute can be dissolved in a solution at a given temperature, it is called as the saturated solution.