JEE Advanced 2017 · Paper 2 · Chemistry Q8

← JEE Advanced 2017 · Paper 2

ChemistryMultiple correct+4 / -2Question 26 of 54

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

Adsorption is accompanied by decrease in enthalpy and decrease in entropy of the system

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

Cloud is an emulsion type of colloid in which liquid is dispersed phase and gas is dispersion medium

Brownian motion of colloidal particles does not depend on the size of the particles but depends on viscosity of the solution

Answer and worked solution

Official answer: A, B

(A) Adsorption is spontaneous and lowers the freedom of the adsorbate, so $\Delta S<0$ . It must then have $\Delta H<0$ . True.
(B) A gas with a higher critical temperature is more easily liquefied, so ethane is adsorbed more than $\ce{N2}$ . True.
(C) A cloud is an aerosol (liquid dispersed in gas), not an emulsion (liquid in liquid). False.
(D) Brownian motion is more vigorous for smaller particles, so it does depend on size. False.

(A), (B)

Topics:Adsorption Colloids

← Previous question Next question →

JEE Advanced 2017 · Paper 2, Chemistry question 8