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Saturday, 31 October

JEE Main 2021 · ChemistryNumerical answerNumerical valueHardMulti-step

JEE Main 31 August 2021, Shift 2, Chemistry Q55

Question 55 of 90 in this shift, Chemistry question 25 of 30, Section B.

1.22 g of an organic acid is separately dissolved in 100 g of benzene (Kb=2.6 K kg mol−1\mathrm{K_b = 2.6\ K\ kg\ mol^{-1}}) and 100 g of acetone (Kb=1.7 K kg mol−1\mathrm{K_b = 1.7\ K\ kg\ mol^{-1}}). The acid is known to dimerize in benzene but remain as a monomer in acetone. The boiling point of the solution in acetone increases by 0.17°C. The increase in boiling point of solution in benzene in °C is x×10−2x \times 10^{-2}. The value of xx is __________. (Nearest integer) [Atomic mass : C=12.0, H=1.0, O=16.0]

Official answer

13

NTA final key.

Chapter
Solutions
Topic
Colligative Properties
Idea tested
Carboxylic Acid Dimerization in Non-Polar Solvents

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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.