The equilibrium constants for the reactions CH₄(g)+2H₂O(g) ⇌ CO₂(g)+4H₂(g) and CO(g)+H₂O(g) ⇌ CO₂(g)+H₂(g) are K₁ and K₂, respectively. The equilibrium constant for the reaction CH₄(g)+H₂O(g) ⇌ CO₂(g)+3H₂(g) is

Q35 · CSIR-NET Chemistry, December 2019

Paper: CSIR-NET December 2019 · Subject: Physical Chemistry · Chapter: Chemical Kinetics · Topic: Chemical Kinetics – General · Marks: 2 · Difficulty: Medium

The equilibrium constants for the reactions $\mathrm{CH_4(g)+2H_2O(g) \rightleftharpoons CO_2(g)+4H_2(g)}$ and $\mathrm{CO(g)+H_2O(g) \rightleftharpoons CO_2(g)+H_2(g)}$ are $K_1$ and $K_2$, respectively. The equilibrium constant for the reaction $\mathrm{CH_4(g)+H_2O(g) \rightleftharpoons CO_2(g)+3H_2(g)}$ is

(a)$K_1 \cdot K_2$

(b)$K_1-K_2$

(c)$K_1/K_2$

(d)$K_2-K_1$

Answer

Answer (as printed): C

Explanation

(1) CH₄ + 2H₂O ⇌ CO₂ + 4H₂, K₁; (2) CO + H₂O ⇌ CO₂ + H₂, K₂.

Subtracting (2) from (1) gives CH₄ + H₂O ⇌ CO + 3H₂. When reactions are subtracted, their equilibrium constants are divided, so K = K₁/K₂.

The printed target 'CH₄ + H₂O ⇌ CO₂ + 3H₂' is not balanced in O. The intended product is CO, as the book's own solution shows. Answer (c) K₁/K₂.

Study loop for Chemical Kinetics

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