Question

Given the reaction at equilibrium: H2(g) + Cl2(g) ↔ 2 HCl(g) As the pressure increases at constant temperature, the mass of H2(g)

A) decreases
B) increases
C) remains the same

Answer 1

As the pressure increases at constant temperature, the mass of H2 will decrease. Hence the correct answer is option A

Step-by-step explanation:

According to Le Chatelier's principle, an increase in pressure favors the side with fewer moles of gas. In the given reaction, the reactant side (H2 + Cl2) has 2 moles of gas, while the product side (2 HCl) has only 1 mole of gas. Therefore, as the pressure increases at constant temperature, the equilibrium will shift to the left (the reverse reaction), resulting in a decrease in the mass of H2.

Hence the correct answer is option A