JEE Main 2023ChemistryChemical EquilibriumMediumNumerical

JEE Main 2023 — Chemical Equilibrium Question with Solution

JEE Main 2023 (29 Jan Shift 1)

Question

Water decomposes at 2300 K

H2Og→H2g+12O2g

The percent of water decomposing at 2300 K and 1 bar is _____ (Nearest integer). Equilibrium constant for the reaction is 2×10-3 at 2300 K

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Show full solutionCorrect answer: 2
Correct answer
2

Step-by-step explanation

Decomposition of water gives:
H2Og ⇌ H2g + 12O2g

P01-α    P0α       P0α2  partial pr. at eq.

Thus, P01+α2=1            …1

Kp=PH2PO21/2PH2O

P0αP0α21/2P01-α=2×10-3

since α is negligible w.r.t 1 thus, 1-α≈1

⇒αα2=2×10-3

⇒α3/2=23/2×10-3

⇒α=23/2×2/3×10-3×2/3

⇒α=2×10-2,      %α=2%

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About this question

This is a previous-year question from JEE Main 2023, 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.