Question

Clouds, mist, fog and aerosols (such as perfumes and sprays) are colloidal solutions of a:
A. Liquid in a gas
B. Gas in a Liquid
C. Solid in a gas
D. Gas in a solid

Answer 1

A colloid is defined as a mixture that is actually heterogeneous but appears to be homogeneous as the particles are uniformly spread throughout the solution. Colloidal solutions are also called colloidal sols. A colloid consists of two parts , one is a dispersed phase and the other is a dispersion medium .

Complete step by step answer: A common method of classifying the colloid is by checking its dispersed phase and dispersion medium .
Aerosol contains liquid as dispersed phase and gas as dispersion medium , that is , in this liquid is dispersed in gas.
Fog or cloud is a colloidal dispersion of water droplets in a dispersion medium of gas. The formation of colloids takes place when moist and warm air rises from the seas and condense as they reach the atmosphere.
When the dispersion medium is gas, the dispersed phase can be solid or liquid but not gas.
Therefore the correct answer to the question cloud, mist, fog and aerosols are colloidal solutions of a Liquid in a gas.
So, the correct answer is (A).

Additional Information: Colloids show various properties for example colligative properties , tyndall effect , change in colour , Brownian movement . These properties are shown by colloids but there are certain conditions under which colloids show these properties .

Note: There are two types of colloids which are termed as aerosols , one is liquid in gas and the other is solid in gas , in both these colloids the dispersion medium is liquid . In the given question , the aerosol which we are referring to is liquid in gas colloid .