Question

Among the following, correct statement is :

• A. Brownian movement is more pronounced for smaller particles than for bigger-particles.
• B. Sols of metal sulphides are lyophilic.
• C. Hardy Schulze law states that bigger the size of the ions, the greater is its coagulating power.
• D. One would expect charcoal to adsorb chlorine more than hydrogen sulphide.

Answer 1

The Correct Option is A

 Let's analyze each statement given in the options to identify the correct one.

1. Statement: Brownian movement is more pronounced for smaller particles than for bigger particles.
   • Explanation: Brownian movement is the random motion of particles suspended in a fluid (liquid or gas). This movement occurs due to collisions with the fast-moving molecules in the fluid. Smaller particles experience greater impact from these collisions because they have less mass, and hence, they show more noticeable Brownian movement compared to larger particles. This statement is thus correct.
2. Statement: Sols of metal sulphides are lyophilic.
   • Explanation: Lyophilic sols (also known as hydrophilic sols) are those that have a strong affinity for the solvent and are stable. Metal sulphide sols are typically lyophobic, meaning they do not readily interact with water and require stabilizing agents. Thus, this statement is incorrect.
3. Statement: Hardy Schulze law states that bigger the size of the ions, the greater is its coagulating power.
   • Explanation: Hardy Schulze law actually states that the coagulating power of an ion is more dependent on the charge of the ion rather than its size; the greater the charge of the ions, the greater their ability to bring about coagulation of a colloid. Hence, this statement is incorrect.
4. Statement: One would expect charcoal to adsorb chlorine more than hydrogen sulphide.
   • Explanation: Adsorption is usually greater for gases with higher critical temperatures because they have a higher tendency to liquefy. Hydrogen sulphide has a higher critical temperature and higher polarizability compared to chlorine, making it more adsorbable on charcoal. Therefore, this statement is incorrect.

Conclusion: The correct statement is "Brownian movement is more pronounced for smaller particles than for bigger-particles."