Question

Fog is a colloidal solution of:
A) liquid in gas
B) Gas in liquid
C) solid in gas
D) Gas in Gas

Answer 1

Hint: We know that a colloidal solution is a mixture in which microscopically dispersed insoluble particles of one substance are suspended in another substance. The size of the suspended particle can range from 1 to 1000 nanometers. For a mixture to be classified as a colloid, the suspended particles must not settle at the bottom of the container if left undisturbed.

Complete answer:
Colloids usually feature substances that are evenly dispersed in another. So, in such mixtures, the substance that will be dispersed is known as the dispersed phase whereas the substance through which it is dispersed is known as the continuous phase.
According to our question, the correct answer is liquid in gas as Fog is the part of a colloidal system in which liquid is said to be dispersed in gas. Fog is an example of aerosol in which the dispersed phase is liquid and dispersion medium is gas.
Let us have a look on the examples of Colloids
-Blood: We know that blood is a respiration pigment which has albumin protein in water. Pigment part contains albumin that acts as the dispersed phase and the dispersion medium is water. It is a hydrosol.
-Cloud: It contains air which is the dispersion medium and droplets of water as a dispersed phase. These are aerosols.
-Gold sol: It is a metallic solution where gold particles are dispersed in the water.

Therefore, the correct answer is option A.

Note: Colloid solutions show the Tyndall effect which is a phenomenon in which the mean of light which is incident on colloids, scatters due to the interactions between the light and the colloid particles. Also, colloids are heterogeneous in nature.