Each reaction is allowed to come to equilibrium, and then the volume is changed as indicated. Predict the effect (shift right, shift left, or no effect) of the indicated volume change. a. I₂( g) ⇌ 2 I( g) (volume is increased) b. 2 H₂S( g) ⇌ 2 H₂( g) + S₂(g) (volume is decreased) c. I₂(g) + Cl₂(g) ⇌ 2 ICl(g) (volume is decreased)

Key Concepts

Le Chatelier's Principle

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the system will respond by shifting in a direction that counteracts the change. This principle helps predict how a system at equilibrium will react to changes in concentration, temperature, or pressure.

Effect of Volume Change on Gaseous Equilibria

In gaseous equilibria, a decrease in volume increases the pressure of the system. According to Le Chatelier's Principle, the equilibrium will shift toward the side with fewer moles of gas to reduce the pressure. Conversely, an increase in volume would shift the equilibrium toward the side with more moles of gas.

Stoichiometry of the Reaction

The stoichiometry of a chemical reaction provides the ratio of reactants to products. In the reaction 2 H2S(g) ⇌ 2 H2(g) + S2(g), there are 2 moles of H2S on the reactant side and 3 moles of gas (2 moles of H2 and 1 mole of S2) on the product side. Understanding this ratio is crucial for predicting the direction of the shift when volume changes.