JEE Advanced 2021 · Paper 1 · Chemistry Q13

ChemistryMultiple correct+4 / -2Question 32 of 57

The correct statement(s) related to colloids is(are)

The process of precipitating colloidal sol by an electrolyte is called peptization.

Colloidal solution freezes at higher temperature than the true solution at the same concentration.

Surfactants form micelle above critical micelle concentration (CMC). CMC depends on temperature.

Micelles are macromolecular colloids.

Answer and worked solution

Official answer: B, C

Check each option.

(A) Precipitating a sol with an electrolyte is coagulation. Peptization is the reverse, turning a precipitate into a sol. False.
(B) A colloid has far fewer particles than a true solution of the same mass concentration. Its freezing-point depression is therefore smaller, and it freezes at a higher temperature. True.
(C) Micelles form above the CMC, and the CMC depends on temperature (above the Kraft temperature). True.
(D) Micelles are associated colloids, not macromolecular colloids. False.

(B), (C)

Topics:Colloids

JEE Advanced 2021 · Paper 1, Chemistry question 13