Question

Consider the equilibrium CO( g)+3H2( g)⇌CH4( g)+H2O( g) If the pressure applied over the system increases by two fold at constant temperature then

• A. Concentration of reactants and products increases.
• B. Equilibrium will shift in forward direction.
• C. Equilibrium constant increases since concentration of products increases.
• D. Equilibrium constant remains unchanged as concentration of reactants and products remain same.

Answer 1

Answer: (B)

Equilibrium will shift in forward direction.

Answer 2

For the reaction

$$\text{CO (g)} + 3\, \text{H}_2 (g) \rightleftharpoons \text{CH}_4 (g) + \text{H}_2\text{O (g)}$$

the total number of moles of gas on the reactant side is 1 + 3 = 4, and on the product side is 1 + 1 = 2. Increasing the pressure at constant temperature favors the side with fewer moles of gas. Hence, the equilibrium will shift in the forward direction (toward the production of CH₄ and H₂O).