a. Calculate the percent ionization of 0.007 M butanoic acid (𝐾𝑎=1.5×10−5).

검증된 단계별 안내

Step 1: Write the ionization equation for butanoic acid (C₃H₇COOH) in water: C₃H₇COOH (aq) ⇌ C₃H₇COO^- (aq) + H⁺ (aq).

Step 2: Set up the expression for the acid dissociation constant (K_a): K_a = [C₃H₇COO^-][H⁺] / [C₃H₇COOH].

Step 3: Assume that the initial concentration of butanoic acid is 0.007 M and that the change in concentration due to ionization is x. Therefore, at equilibrium, [C₃H₇COO^-] = x, [H⁺] = x, and [C₃H₇COOH] = 0.007 - x.

Step 4: Substitute these equilibrium concentrations into the K_a expression: 1.5 \(\times\) 10^{-5} = (x)(x) / (0.007 - x).

Step 5: Solve the equation for x, which represents the concentration of ionized butanoic acid. Then, calculate the percent ionization using the formula: \(\text{Percent Ionization}\) = \(\left\)( \(\frac{x}{0.007}\) \(\right\)) \(\times\) 100\%.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

주요 개념

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

Ionization of Weak Acids

Weak acids, like butanoic acid, do not completely dissociate in solution. Instead, they establish an equilibrium between the undissociated acid and its ions. The degree of ionization is crucial for calculating the concentration of ions in solution, which directly affects the acid's strength and its pH.

Equilibrium Constant (Ka)

The acid dissociation constant (Ka) quantifies the strength of an 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. A smaller Ka value indicates a weaker acid, which is essential for determining the extent of ionization in weak acids like butanoic acid.

Percent Ionization

Percent ionization is a measure of the extent to which an acid ionizes in solution, expressed as a percentage. It is calculated by dividing the concentration of ionized acid by the initial concentration of the acid, then multiplying by 100. This concept helps in understanding the effectiveness of an acid in solution and is particularly useful for comparing the strengths of different acids.