Question

The degree of dissociation of PCl₅(g) obeying the equilibrium PCl₅ rightleftharpoons PCl₃ + Cl₂ is related to the equilibrium pressure by:

• A. \(\alpha \propto \dfrac{1}{P^4}\)
• B. \(\alpha \propto \dfrac{1}{\sqrt{P}}\)
• C. \(\alpha \propto \dfrac{1}{P^2}\)
• D. α ∝ P

Hint:

For 1 → 2 gaseous equilibria, dissociation increases at low pressure.

Answer 1

The Correct Option is B

Step 1: One mole forms two moles on dissociation.
Step 2: For such equilibria: α ∝ \frac1√(P)