Question

Pumice stone is an example of

• A. Solid sol
• B. Emulsion
• C. Aerosol
• D. Solid foam

Hint:

Gas dispersed in solid forms solid foam, while gas in liquid forms foam.

Answer 1

The Correct Option is D

Step 1: Understanding pumice stone.
Pumice stone is a volcanic rock that contains a large number of air-filled cavities trapped in a solid matrix.

Step 2: Classification of colloids.
When gas is dispersed in a solid medium, the colloidal system formed is called a solid foam.

Step 3: Conclusion.
Since pumice stone consists of gas trapped in solid, it is a solid foam.