Question

Fog is a solution of:

• A. Liquid in gas
• B. Gas in liquid
• C. Solid in gas
• D. Gas in gas

Hint:

Fog is formed when water vapor condenses into tiny droplets suspended in the air, creating a liquid-in-gas mixture.

Answer 1

The Correct Option is A

Compare fog with two familiar mixtures: smoke rising from a fire, and the fizz in a bottle of soda water.

1. Liquid in gas: fog is made of tiny water droplets floating in air, closer to a fine mist than to smoke or fizz, which is exactly liquid dispersed in gas.
2. Gas in liquid: the fizz in soda water is carbon dioxide gas trapped in liquid, the opposite arrangement from fog's water-in-air setup.
3. Solid in gas: smoke is made of solid soot particles floating in air, not liquid droplets, so this describes smoke rather than fog.
4. Gas in gas: ordinary air, with its gases blended uniformly and no visible droplets or particles, does not match fog's visible mist.

Fog matches the water-droplets-in-air picture, so the correct answer is liquid in gas.

Answer 2

Identify two things separately for fog: what physical state is doing the dispersing (the medium), and what physical state is dispersed within it (the dispersed phase).

1. Liquid in gas: the medium is air, a gas, and the dispersed phase is fine water droplets, a liquid. Both parts match fog's actual makeup.
2. Gas in liquid: here the medium would have to be a liquid with gas dispersed in it, the reverse of fog's air-and-water-droplets setup.
3. Solid in gas: here the dispersed phase would need to be solid particles, but fog's droplets are liquid water, not solid particles.
4. Gas in gas: here both parts would need to be gases, but fog clearly contains a visible liquid component, the droplets.

Since fog's medium is a gas and its dispersed phase is a liquid, the correct answer is liquid in gas.