JEE Main 2017 · ChemistryMultiple choiceSingle correctMediumMulti-step

JEE Main 2 April 2017 (offline), Chemistry Q37

Question 37 of 90 in this shift, Chemistry question 7 of 30.

The 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 a dimer in benzene, percentage association of acetic acid in benzene will be : (

K_f

for benzene

=5.12\ \mathrm{K\,kg\,mol^{-1}}

)

(1)74.6%
(2)94.6%Official answer
(3)64.6%
(4)80.4%

Official answer

Option 2

CBSE answer key (25/04/2017, used for result).

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

Same topic in other shifts

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Question text from the official JEE Main paper published by NTA (CBSE ran the 2017 exam); answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.