Calculate the equilibrium constant for each of the acid–base reactions shown.
b.

Verified step by step guidance

1. Identify the acid and base on both sides of the reaction. Determine which species is donating a proton (acid) and which is accepting a proton (base).
2. Write the equilibrium constant expression for the acid-base reaction. The equilibrium constant (K_eq) is given by the formula: $K$_eq = K_a^acid1K_a^acid2, where $K$_a values correspond to the acids on each side of the reaction.
3. Look up the pKa values for the acids on both sides of the reaction. Recall that $K$_a = 10^-pKa, so you can calculate the Ka values if needed.
4. Substitute the Ka values into the equilibrium constant expression. Ensure that the acid on the reactant side is in the numerator and the acid on the product side is in the denominator.
5. Simplify the expression to determine the equilibrium constant (K_eq). This will indicate whether the reaction favors the reactants or the products.

Key Concepts

Acid-Base Reactions

Acid-base reactions involve the transfer of protons (H+) between reactants. An acid is a substance that donates protons, while a base accepts them. Understanding the nature of the acids and bases involved is crucial for predicting the direction of the reaction and calculating the equilibrium constant.

Equilibrium Constant (K)

The equilibrium constant (K) quantifies the ratio of the concentrations of products to reactants at equilibrium for a given reaction at a specific temperature. For acid-base reactions, K can be expressed in terms of the concentrations of the conjugate acids and bases. A larger K value indicates a reaction that favors product formation.

Conjugate Acid-Base Pairs

Conjugate acid-base pairs consist of an acid and its corresponding base that differ by a single proton. When an acid donates a proton, it forms its conjugate base, and vice versa. Recognizing these pairs is essential for calculating equilibrium constants and understanding the dynamics of acid-base reactions.