In this Course on Purity of Matter, we will understand the Mixtures, Types of Mixtures namely Solutions, Suspensions and Colloids, Saturated and Unsaturated Solutions and Solubility, Techniques of Separation of Mixtures into Their Constituents and the Physical and Chemical Properties of Matter and Physical and Chemical Changes. The distinction between Elements (Metals, Non Metals and Metalloids) and Compounds will also be understood.

In a solution, the relative proportion of the solute and solvent can be varied. Depending upon the amount of solute present in a solution, it can be called a dilute, concentrated or a saturated solution. Dilute and concentrated are comparative terms.

At any particular temperature, a solution that has dissolved as much solute as it is capable of dissolving, is said to be a saturated solution. In other words, when no more solute can be dissolved in a solution at a given temperature, it is called a saturated solution. The amount of the solute present in the saturated solution at this temperature is called its solubility. If the amount of solute contained in a solution is less than the saturation level, it is called an unsaturated solution.

We can conclude from the above activity that the different substances in a given solvent have different solubility at the same temperature. The concentration of a solution is the amount of solute present in a given amount (mass or volume) of solution, or the amount of solute dissolved in a given mass or volume of solvent.