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JEE Main 18 March 2021, Shift 2, Chemistry Q54

Question 54 of 90 in this shift, Chemistry question 24 of 30, Section B.

A solute A dimerizes in water. The boiling point of a 2 molal solution of A is 100.52℃. The percentage association of A is __________. (Round off to the Nearest Integer). [Use :

\mathrm{K_b}

for water = 0.52 K kg mol

^{-1}

Boiling point of water = 100℃]

Official answer

100

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

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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.