JEE Main 2021ChemistryChemical EquilibriumChemical Equilibrium Law Of Mass Action And Equilibrium ConstantmediumNumerical

JEE Main 2021Chemical Equilibrium Question with Solution

From: JEE Main 2021 (Online) 16th March Morning Shift

Question

For the reaction at 495 K, rG = 9.478 kJ mol1.
If we start the reaction in a closed container at 495 K with 22 millimoles of A, the amount of B in the equilibrium mixture is ____________ millimoles.
(Round off to the Nearest Integer). [R = 8.314 J mol1 K1; ln 10 = 2.303]

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Show full solutionCorrect answer: 20
Correct answer
20

Step-by-step explanation

Go = RT ln Keq

9.478 103 = 495 8.314 ln Keq

ln Keq = 2.303 = ln 10

So, Keq = 10

Now, A(g) B(g)

\matrix{ {t = 0} & {22} & 0 \cr {t = t} & {22 - x} & x \cr }



x = 20

So, millimoles of B = 20

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About this question

This is a previous-year question from JEE Main 2021, covering the Chemical Equilibrium 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.