Question

You are given three different solutions in three test tubes: 1. Unsaturated solution 2. saturated solution 3. supersaturated solution. How will you determine which solution is unsaturated?

Answer 1

A test tube in which more solute can be dissolved will be the test tube containing unsaturated solution.

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.

Example: Suppose that $100\mathrm{mL}$ of water is taken and a solute x is dissolved in it.

• The maximum amount of x that can be dissolved in it at $20°\mathrm{C}$ is $10\mathrm{g}$. If you add, let us say, $4\mathrm{g}$, the solute x will get dissolved in it because $100\mathrm{mL}$ of water can hold a maximum of $10\mathrm{g}$ at the given temperature and $4\mathrm{g}$ is lesser than$10\mathrm{g}$.
• But when you add $10\mathrm{g}$ of x in $100\mathrm{mL}$ of water, you get a saturated solution as this is the maximum amount of x that can be dissolved in it at that given temperature.
• At this stage, the solution is said to be saturated with x.
• Note that, on changing the amount of solvent and temperature, the amount of solute required to make a saturated solution changes.
• In a nutshell, for this particular example, if the amount of solute dissolved is less than$10\mathrm{g}$, will make an unsaturated solution, dissolution of exactly $10\mathrm{g}$ of solute will make a saturated solution, and dissolution of solute more than $10\mathrm{g}$ at this temperature will make a supersaturated solution.