Question

The correct statement(s) about surface properties is(are)

• A. Adsorption is accompanied by decrease in enthalpy and decrease in entropy of the system
• 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
• 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 1

Answer: (A), (B)

The correct options are
A Adsorption is accompanied by decrease in enthalpy and decrease in entropy of the system
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

In adsorption process both $\Delta H$ and $\Delta S$ is -ve. Higher the critical temperature of a gas higher is the extent of adsorption.
Cloud is not an emulsion.
Brownian motion depends on the size of the particles.