Question

Which of the following colloidal system represents a gel?

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

Hint:

Remember that gels exhibit semi-solid characteristics because the liquid is trapped within a solid network.

Answer 1

The Correct Option is C

Step 1: Recall what a colloid is named after.
A colloidal system is named by two things: the dispersed phase (the tiny scattered particles) and the dispersion medium (what they float in). The question asks which combination is a gel.
Step 2: Recall what a gel looks like.
Think of jelly, butter, or cheese. They feel solid but hold a lot of liquid trapped inside a solid network. So a gel is a liquid spread inside a solid.
Step 3: Match liquid in solid to the options.
Liquid as the dispersed phase and solid as the medium is exactly the third option, liquid in solid.
Step 4: Rule out solid in liquid.
Solid particles floating in a liquid is a sol, like paint or muddy water, not a gel.
Step 5: Rule out the gas based ones.
Solid in gas (like smoke) and liquid in gas (like clouds or mist) are aerosols, again not gels.
Step 6: Conclude.
The gel is the liquid in solid system.
\[ \boxed{\text{Liquid in solid}} \]