Question

Consider the equilibrium: \[ \text{CO(g)} + \text{3H}_2\text{(g)} \rightleftharpoons \text{CH}_4\text{(g)} + \text{H}_2\text{O(g)} \] If the pressure applied over the system increases by two fold at constant temperature then:

• A. (A) and (B) only
• B. (A), (B) and (D) only
• C. (B) and (C) only
• D. (A), (B) and (C) only

Hint:

Le Chatelier's principle helps predict the direction of equilibrium shifts when a system is disturbed. Increasing pressure favors the side with fewer gas molecules in a reaction.

Answer 1

The Correct Option is A

According to Le Chatelier's principle, increasing the pressure on a gaseous system will favor the side with fewer moles of gas. In the given equilibrium reaction, the left-hand side has 4 moles of gas (1 mole of CO and 3 moles of H\(_2\)) and the right-hand side has 2 moles of gas (1 mole of CH\(_4\) and 1 mole of H\(_2\)O). Therefore, increasing the pressure will shift the equilibrium towards the right (in the forward direction), increasing the concentration of products and decreasing the concentration of reactants. 
- (A) The concentration of reactants and products increases because the equilibrium shifts toward the products side. 
- (B) The equilibrium will shift in the forward direction to produce more CH\(_4\) and H\(_2\)O. 
- (C) The equilibrium constant remains unchanged, as pressure does not affect the value of the equilibrium constant at constant temperature. 
Therefore, the correct answer is (1) (A) and (B) only.