When the following equilibria are disturbed by increasing the pressure, does the concentration of reaction products increase, decrease, or remain the same?
a. 2 CO₂(g) ⇌ 2 CO(g) + O₂(g)

Verified step by step guidance

1. Analyze the equilibrium reaction: 2 CO2(g) ⇌ 2 CO(g) + O2(g). This is a gaseous reaction, so the effect of pressure changes can be determined using Le Chatelier's Principle.
2. Count the number of moles of gas on each side of the reaction. On the left side (reactants), there are 2 moles of CO2. On the right side (products), there are 2 moles of CO and 1 mole of O2, for a total of 3 moles of gas.
3. According to Le Chatelier's Principle, if the pressure is increased, the equilibrium will shift to the side with fewer moles of gas to reduce the pressure. In this case, the left side (reactants) has fewer moles of gas (2 moles) compared to the right side (3 moles).
4. Since the equilibrium shifts to the left (toward the reactants) when pressure is increased, the concentration of the reaction products (CO and O2) will decrease.
5. Conclude that increasing the pressure causes the equilibrium to favor the formation of reactants, leading to a decrease in the concentration of the products.

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 adjust to counteract the change and restore a new equilibrium. In the context of pressure changes, the system will shift in the direction that reduces the pressure, which typically means favoring the side with fewer gas molecules.

Equilibrium Constant (K)

The equilibrium constant (K) quantifies the ratio of concentrations of products to reactants at equilibrium for a given reaction at a specific temperature. Changes in pressure can affect the concentrations of gases involved in the reaction, but the value of K remains constant unless the temperature changes. Understanding K helps predict how concentrations will shift in response to pressure changes.

Mole Ratio and Gas Volume

In gas reactions, the mole ratio of reactants and products is crucial for understanding how changes in pressure affect the system. According to the ideal gas law, increasing pressure favors the side of the reaction with fewer moles of gas. In the given equilibrium, there are 3 moles of gas on the product side (2 CO + 1 O2) and 2 moles on the reactant side (2 CO2), indicating that increasing pressure will shift the equilibrium towards the reactants.