Question

At the equilibrium of the reaction $2X\left(g\right)+Y\left(g\right)\rightleftharpoons X_{2}Y\left(g\right)$ the number of moles of $X_{2}Y$ at equilibrium is affected by the:

• A. temperature and pressure
• B. temperature only
• C. pressure only
• D. temperature, pressure and catalyst used

Answer 1

The correct option is A temperature and pressure

On increasing the temperature in an endothermic reaction, the reaction will proceed in a forward direction and the number of moles of product increases. While an increase in temperature in the exothermic reaction will result in an increase in the rate of backward reaction, hence, the number of moles of a product decreases. Thus, temperature affects the number of moles of product formed.

In a reacting system, the pressure is more at the reactant side if the total number of gaseous moles of reactant is more than the total number of gaseous moles of product. So, on increasing the pressure of the system, the reaction will proceed in a forward reaction as the system will try to oppose the change. Hence, pressure affects the equilibrium of the reaction.

The catalyst increases the rate of reaction equally in both the directions hence, it does not affect the equilibrium of the reaction.