Write the chemical equation and the Kb expression for the reaction of each of the following bases with water: (c) benzoate ion, C6H5CO2-

Verified step by step guidance

1. Write the chemical formula for benzoate ion, which is C6H5CO2-.
2. Identify that benzoate ion is a base and will accept a proton (H+) from water, which acts as the acid in this reaction.
3. Write the balanced chemical equation for the reaction of benzoate ion with water: C6H5CO2- + H2O \\leftrightarrow C6H5CO2H + OH-.
4. Identify the products of the reaction: benzoic acid (C6H5CO2H) and hydroxide ion (OH-).
5. Write the expression for the base dissociation constant (Kb) for this reaction: Kb = \frac{[C6H5CO2H][OH-]}{[C6H5CO2-]}

Key Concepts

Base Ionization

Base ionization refers to the process by which a base reacts with water to produce hydroxide ions (OH-) and its conjugate acid. In the case of the benzoate ion (C6H5CO2-), it acts as a Brønsted-Lowry base, accepting a proton from water, leading to the formation of benzoic acid (C6H5COOH) and hydroxide ions.

Chemical Equations

A chemical equation represents the reactants and products of a chemical reaction using their chemical formulas. For the reaction of the benzoate ion with water, the equation can be written as: C6H5CO2- + H2O ⇌ C6H5COOH + OH-. This equation illustrates the reversible nature of the reaction, indicating that the products can also revert to the reactants.

Equilibrium Constant (Kb)

The base dissociation constant (Kb) quantifies the strength of a base in solution, representing the equilibrium between the base, its conjugate acid, and hydroxide ions. For the benzoate ion, the Kb expression is given by Kb = [C6H5COOH][OH-] / [C6H5CO2-], where the concentrations of the products are in the numerator and the concentration of the reactant is in the denominator, reflecting the extent of ionization.