JEE Main 2022ChemistrySolutionsHardNumerical

JEE Main 2022 — Solutions Question with Solution

JEE Main 2022 (27 Jun Shift 2)

Question

A solution containing 2.5×10-3 kg of a solute dissolved in 75×10-3 kg of water boils at 373.535 K. The molar mass of the solute is mol-1· [nearest integer] (Given : KbH2O=0.52 K kg mol-1 and boiling point of water =373.15 K)

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Show full solutionCorrect answer: 45
Correct answer
45

Step-by-step explanation

ΔTb=iKbm

ΔTb=Elevation of boiling pointKb= molal boiling point elevation constantm=molalityi=van't hoff factor

m=2.5M×100075

∆Tb=Tb-TboTb=Boiling point of the solutionTbo=Boiling point of the solvent∆Tb=373.535-373.15        =0.385 K

ΔTb=iKbm

0.385=1×0.52×2.5×1000M×75

The molar mass of the solute,M=45 g/ml.

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About this question

This is a previous-year question from JEE Main 2022, covering the Solutions chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.