JEE Main 2021ChemistryChemical EquilibriumEasyNumerical

JEE Main 2021 — Chemical Equilibrium Question with Solution

JEE Main 2021 (27 Jul Shift 1)

Question

PCl5⇌PCl3+Cl2    Kc=1.844
3.0 moles of PCl5 is introduced in a 1L closed reaction vessel at 380 K. The number of moles of PCl5 at equilibrium is —×10-3
(Round off to the Nearest Integer)

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Show full solutionCorrect answer: 1400
Correct answer
1400

Step-by-step explanation

         PCl5( g)⇌PCl3( g)+Cl2( g)    Kc=1.844t=0     3                 0            0t=teq   3-x           x             x


⇒PCl3Cl2PCl5=x23-x=1.844
⇒x2+1.844-5.532=0
⇒x=-1.844+(1.844)2+4×5.5322
≡1.60
⇒ Moles of PCl5=3-1.60=1.40

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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.