JEE Main 2022ChemistrySolutionsMediumNumerical

JEE Main 2022 — Solutions Question with Solution

JEE Main 2022 (29 Jun Shift 1)

Question

1.2 mL of acetic acid is dissolved in water to make 2.0 L of solution. The depression in freezing point observed for this strength of acid is 0.0198 °C. The percentage of dissociation of the acid is (Nearest integer) [Given : Density of acetic acid is 1.02 g mL-1 Molar mass of acetic acid is 60 gmol-1
KfH2O=1.85 K kg mol-1]

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Show full solutionCorrect answer: 5
Correct answer
5

Step-by-step explanation

M=d×V=1.02×1.2=1.224gm

Moles of acetic acid =0.0204 moles in 2 L

So molality =0.0102 mol/kg

Now ΔTf=i×Kf×m

i=1+α for acetic acid

0.0198=1+α×1.85×0.0102

α=0.04928

≅5%

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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.