Predict the products of the following acid–base reactions, and predict whether the equilibrium lies to the left or to the right of the reaction arrow:
(a) O^2-(aq) + H₂O(l) ⇌
(b) CH₃COOH(aq) + HS^-(aq) ⇌
(c) NO₂^-(aq) + H₂O(l) ⇌

Verified step by step guidance

1. Identify the acid and base in the reaction. Here, \( \text{NO}_2^- \) acts as a base and \( \text{H}_2\text{O} \) acts as an acid.
2. Determine the conjugate acid and conjugate base. \( \text{NO}_2^- \) will accept a proton to form \( \text{HNO}_2 \), and \( \text{H}_2\text{O} \) will donate a proton to form \( \text{OH}^- \).
3. Write the balanced chemical equation for the reaction: \( \text{NO}_2^- + \text{H}_2\text{O} \rightleftharpoons \text{HNO}_2 + \text{OH}^- \).
4. Consider the strength of the acids and bases involved. \( \text{HNO}_2 \) is a weak acid, and \( \text{OH}^- \) is a strong base.
5. Predict the direction of the equilibrium. Since \( \text{OH}^- \) is a strong base, the equilibrium will lie to the left, favoring the reactants.

Key Concepts

Acid-Base Reactions

Acid-base reactions involve the transfer of protons (H+) between reactants. In this context, an acid donates a proton, while a base accepts it. Understanding the roles of acids and bases is crucial for predicting the products of the reaction and determining the direction of equilibrium.

Equilibrium Position

The position of equilibrium in a chemical reaction indicates the relative concentrations of reactants and products at equilibrium. If the equilibrium lies to the right, products are favored; if to the left, reactants are favored. Factors such as concentration, temperature, and the nature of the reactants influence this position.

Water as a Solvent

Water is often referred to as the 'universal solvent' due to its ability to dissolve many substances, including acids and bases. In acid-base reactions, water can act as a medium for proton transfer, and its role in the reaction can affect the strength of the acids and bases involved, influencing the overall reaction dynamics.