What is the percent ionization of an acetic acid solution at the following concentrations? a. 1.00 M b. 0.500 M c. 0.100 M d. 0.0500 M

Name: Chemistry: A Molecular Approach
Author: Tro
ISBN: 9780134112831

검증된 단계별 안내

insert step 1: Write the chemical equation for the ionization of acetic acid (CH3COOH) in water: CH3COOH (aq) ⇌ CH3COO^- (aq) + H^+ (aq).

insert step 2: Write the expression for the acid dissociation constant (Ka) for acetic acid: Ka = [CH3COO^-][H^+]/[CH3COOH].

insert step 3: Use the given concentration of acetic acid to set up an ICE (Initial, Change, Equilibrium) table to determine the equilibrium concentrations of the species involved.

insert step 4: Assume that the change in concentration of CH3COOH is x, and express the equilibrium concentrations in terms of x.

insert step 5: Solve for x using the Ka value for acetic acid (1.8 x 10^-5) and calculate the percent ionization using the formula: Percent Ionization = (x/initial concentration) * 100.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Ionization of Weak Acids

Weak acids, like acetic acid, do not fully dissociate in solution. Instead, they establish an equilibrium between the undissociated acid and its ions. The degree of ionization is influenced by the concentration of the acid; lower concentrations typically lead to higher percent ionization due to less competition among molecules for protons.

Percent Ionization Calculation

Percent ionization is calculated using the formula: (concentration of ionized acid / initial concentration of acid) × 100%. This metric helps quantify how much of the acid has dissociated into ions, providing insight into the strength of the acid and its behavior in solution.

Equilibrium Constant (Ka)

The acid dissociation constant (Ka) quantifies the strength of a weak acid in solution. It is defined as the ratio of the concentration of the products (ions) to the concentration of the reactants (undissociated acid) at equilibrium. Knowing Ka allows for the calculation of ionization at various concentrations, as it remains constant for a given acid at a specific temperature.