JEE Main 2021ChemistrySome Basic Concepts of ChemistryMediumNumerical

JEE Main 2021 — Some Basic Concepts of Chemistry Question with Solution

JEE Main 2021 (16 Mar Shift 1)

Question

A 6.50 molal solution of KOHaq. has a density of 1.89 g cm-3. The molarity of the solution is mol dm-3. (Round off to the Nearest Integer).

[Atomic masses: K:39.0 u; O:16.0 u; H:1.0 u]

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Show full solutionCorrect answer: 9
Correct answer
9

Step-by-step explanation

6.5 molal KOH=1000 gm solvent has 6.5 moles KOH

so, wt. of solute =6.5×56

=364 gm

wt. of solution =1000+364=1364

Volume of solution =13641.89 mℓ

Molarity =mole of soluteVsolution  in Litre

=9.00

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About this question

This is a previous-year question from JEE Main 2021, covering the Some Basic Concepts of Chemistry 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.