JEE Chemistry · Medium

Chemical and Ionic Equilibrium: Degree of dissociation MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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Degree of dissociationMediumQuestion 600408

Question

For PCl₅ ⇌ PCl₃ + Cl₂, if 1 mol PCl₅ is taken and α is the degree of dissociation, moles of each at equilibrium are:
  1. A
    PCl₅: 1−α, PCl₃: α, Cl₂: α
    Correct
  2. B
    PCl₅: α, PCl₃: 1−α, Cl₂: 1−α
  3. C
    PCl₅: 1, PCl₃: α, Cl₂: α
  4. D
    All = 1/3

Correct answer

PCl₅: 1−α, PCl₃: α, Cl₂: α

Explanation

Starting with 1 mol PCl₅. At equilibrium: PCl₅ = 1−α, PCl₃ = α, Cl₂ = α. Total = 1+α moles.