The correct statement(s) about surface properties is(are)
- (A)Adsorption is accompanied by decrease in enthalpy and decrease in entropy of the system✓ Correct
- (B)The critical temperatures of ethane and nitrogen are 563 K and 126 K, respectively. The adsorption of ethane will be more than that of nitrogen on same amount of activated charcoal at a given temperature✓ Correct
- (C)Cloud is an emulsion type of colloid in which liquid is dispersed phase and gas is dispersion medium
- (D)Brownian motion of colloidal particles does not depend on the size of the particles but depends on viscosity of the solution
Answer: (A), (B)
Solution
[A] Correct: Adsorption is an exothermic process () and involves ordering of molecules on the surface ().
[B] Correct: Higher critical temperature indicates stronger intermolecular forces and better adsorbability. Ethane (563 K) has a much higher critical temperature than nitrogen (126 K), so ethane will be adsorbed more readily.
[C] Incorrect: Cloud is an aerosol (liquid dispersed in gas), not an emulsion (liquid in liquid).
[D] Incorrect: Brownian motion depends on both particle size (smaller particles show more motion) and viscosity of the medium.
[B] Correct: Higher critical temperature indicates stronger intermolecular forces and better adsorbability. Ethane (563 K) has a much higher critical temperature than nitrogen (126 K), so ethane will be adsorbed more readily.
[C] Incorrect: Cloud is an aerosol (liquid dispersed in gas), not an emulsion (liquid in liquid).
[D] Incorrect: Brownian motion depends on both particle size (smaller particles show more motion) and viscosity of the medium.
JEE Advanced · 2017 · 21 May 2017 · Paper 2 · One or more correct options