Write the equilibrium constant expressions for the following reactions:2 CO(g) + O2(g) ⇌ 2 CO2(g)

Verified step by step guidance

1. Identify the balanced chemical equation: \(2 \text{CO}(g) + \text{O}_2(g) \rightleftharpoons 2 \text{CO}_2(g)\).
2. Recall that the equilibrium constant expression \(K_c\) is written as the ratio of the concentrations of the products to the reactants, each raised to the power of their coefficients in the balanced equation.
3. Write the expression for the equilibrium constant \(K_c\) for the reaction: \(K_c = \frac{[\text{CO}_2]^2}{[\text{CO}]^2[\text{O}_2]}\).
4. Note that the concentrations \([\text{CO}_2]\), \([\text{CO}]\), and \([\text{O}_2]\) are in terms of molarity (moles per liter) at equilibrium.
5. Ensure that the expression reflects the stoichiometry of the balanced equation, with each concentration term raised to the power of its respective coefficient.

Key Concepts

Equilibrium Constant (K)

The equilibrium constant (K) is a numerical value that expresses the ratio of the concentrations of products to reactants at equilibrium for a given chemical reaction. It is specific to a particular reaction at a certain temperature and indicates the extent to which a reaction proceeds. A large K value suggests that products are favored, while a small K value indicates that reactants are favored.

Reaction Quotient (Q)

The reaction quotient (Q) is a measure of the relative concentrations of reactants and products at any point in time during a reaction. It is calculated using the same formula as the equilibrium constant but with the current concentrations. Comparing Q to K helps determine the direction in which a reaction will proceed to reach equilibrium: if Q < K, the reaction shifts right to produce more products, and if Q > K, it shifts left to produce more reactants.

Stoichiometry in Equilibrium Expressions

Stoichiometry refers to the coefficients of reactants and products in a balanced chemical equation, which are used to formulate the equilibrium constant expression. For the reaction 2 CO(g) + O2(g) ⇌ 2 CO2(g), the equilibrium expression is K = [CO2]^2 / ([CO]^2[O2]), where the concentrations are raised to the power of their respective coefficients. This reflects the relationship between the amounts of substances at equilibrium.