Exams › JEE Main › Chemistry

Which of the following is an example of an irreversible colloid when water acts as the dispersion medium?

1. Clay
2. Platinum
3. Fe(OH)3
4. All of these

Correct answer: All of these

Solution

Irreversible (lyophobic) colloids cannot be reformed simply by adding the dispersion medium once coagulated. Sols of clay, platinum (and other metals), and Fe(OH)3 are all lyophobic/irreversible in water, so 'All of these' is correct.

Related JEE Main Chemistry questions

• At constant temperature, the Freundlich adsorption relation for a gas adsorbed on a solid can be written in terms of the amount adsorbed per unit mass of adsorbent as:
• Which of the following forms cationic micelles when its concentration exceeds a certain limit?
• In a micelle, how are the polar and non-polar regions arranged?
• A colloidal dispersion is placed in an electric field, and its particles migrate toward the anode. If the same sol is coagulated using NaCl, BaCl2, and AlCl3 solutions, what is the correct order of their coagulating ability?
• Which of the following electrolytes is the most effective for coagulating ferric hydroxide sol?
• How does alum aid in the purification of water?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →