Question

What are colloids? Give two examples.

Answer 1

Colloids: A colloid is a solution in which the size of solute particles is between those in true solutions and those in suspensions.

• A colloid is a mixture in which particles of an insoluble substance are suspended throughout another substance.
• In this solution in which the size of solute particles is between those in true solutions and those in suspensions.
• The size of particle ranges from 1 nanometer$\left({10}^{-9}\right)m$ to 1 micrometer $\left({10}^{-6}\right)m$
• In a colloidal solution, these particles can scatter light and the path of the light beam becomes visible.
• The scattering of light by colloidal particles is known as the Tyndall effect.
• Colloids are heterogeneous in nature,

Two examples of colloids are:
Examples 1: Smoke and Dust in the air

In this case, solid dust particles are suspended in a gaseous air medium.

Examples2: Milk and Mayonnaise

In this example, both the solute and solvent are liquid and called an emulsion.