JEE Main 2022 · ChemistryMultiple choiceSingle correctMediumCalculation

JEE Main 25 June 2022, Shift 2, Chemistry Q63

Question 63 of 90 in this shift, Chemistry question 3 of 30, Section A.

Solute A associates in water. When 0.7 g of solute A is dissolved in 42.0 g of water, it depresses the freezing point by 0.2 °C. The percentage association of solute A in water, is : [Given: Molar mass of A = 93

\mathrm{g\ mol^{-1}}

. Molal depression constant of water is 1.86

\mathrm{K\ kg\ mol^{-1}}

(1)50%
(2)60%
(3)70%
(4)80%Official answer

Official answer

Option 4

NTA final key.

Chapter: Solutions
Topic: Colligative Properties
Idea tested: Degree of Association from Van't Hoff Factor

Same idea in other shifts

Asked 4× in all

26 Feb 2021, Shift 2 · Q55When 12.2 g of benzoic acid is dissolved in 100 g of water, the freezing point of solution was found to be $-0.93^\circ$ C…MediumNumerical value
18 Mar 2021, Shift 2 · Q54A solute A dimerizes in water. The boiling point of a 2 molal solution of A is 100.52℃. The percentage association of A is __________.…MediumNumerical value
2 Apr 2017 (offline) · Q37The freezing point of benzene decreases by 0.45°C when 0.2 g of acetic acid is added to 20 g of benzene. If acetic acid associates to form…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.