Question

Although the water is transparent, and there are water droplets present in the fog then why are we not able to see things during fog?

Answer 1

Hint: Saturation is that point at which no more amount of solute is added into solvent. Aerosol is a colloidal system of liquid in gas. The phenomenon of scattering of light occurs in colloidal solutions.

Complete answer:
Saturation is that point at which no more amount of solute is added into solvent. Aerosol is a colloidal system of liquid particles (water droplets here) in gas (air here). In the early morning, temperature is low and hence water droplets make a colloidal solution in air (saturated one). This colloidal solution would show the phenomenon of scattering of light which involves the deviation of light by striking the colloidal particles. As a result, we are not able to see things during fog. With increase in temperature, the colloidal solution becomes a clear solution due to increase in solubility. Clear solution doesn’t show the phenomenon of scattering of light and hence we are able to see things properly.

Note:
 It is important to note that we are not able to see things during fog because of the saturated solution of water droplets in air which makes it a colloidal system. Due to the scattering of sunlight from this colloidal system, we are not able to see things during fog. However, with increase in temperature, the solubility of water droplets increases in air which makes the solution clear and doesn’t allow the scattering of light.