Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. a. a solution that is 0.195 M in HC₂H₃O₂ and 0.125 M in KC₂H₃O₂ b. a solution that is 0.255 M in CH₃NH₂ and 0.135 M in CH₃NH₃Br

검증된 단계별 안내

Identify the type of solution: Both solutions are buffer solutions. Solution (a) is an acetic acid (HC2H3O2) and acetate ion (C2H3O2-) buffer, while solution (b) is a methylamine (CH3NH2) and methylammonium ion (CH3NH3+) buffer.

Use the Henderson-Hasselbalch equation for buffer solutions: \( \text{pH} = \text{pK}_a + \log \left( \frac{[\text{A}^-]}{[\text{HA}]} \right) \) for acidic buffers and \( \text{pOH} = \text{pK}_b + \log \left( \frac{[\text{B}]}{[\text{BH}^+]} \right) \) for basic buffers.

For solution (a), find the \( \text{pK}_a \) of acetic acid (HC2H3O2) using a reference table. Then, substitute \([\text{A}^-] = 0.125 \text{ M}\) and \([\text{HA}] = 0.195 \text{ M}\) into the Henderson-Hasselbalch equation to find the pH.

For solution (b), find the \( \text{pK}_b \) of methylamine (CH3NH2) using a reference table. Then, substitute \([\text{B}] = 0.255 \text{ M}\) and \([\text{BH}^+] = 0.135 \text{ M}\) into the Henderson-Hasselbalch equation to find the pOH.

Convert the pOH to pH for solution (b) using the relation \( \text{pH} = 14 - \text{pOH} \).

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

도움이 되었나요?

주요 개념

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

Equilibrium and ICE Tables

An ICE table (Initial, Change, Equilibrium) is a tool used to organize the concentrations of reactants and products in a chemical equilibrium problem. It helps in calculating the changes in concentration that occur as the system reaches equilibrium. Understanding how to set up and interpret an ICE table is crucial for solving equilibrium problems, including those involving weak acids and bases.

pH and Acid-Base Chemistry

pH is a measure of the acidity or basicity of a solution, defined as the negative logarithm of the hydrogen ion concentration. In the context of weak acids and their conjugate bases, the pH can be calculated using the Henderson-Hasselbalch equation, which relates the pH of a buffer solution to the concentration of the acid and its conjugate base. This concept is essential for determining the pH of solutions containing weak acids and their salts.

Buffer Solutions

A buffer solution is a system that resists changes in pH upon the addition of small amounts of acid or base. It typically consists of a weak acid and its conjugate base or a weak base and its conjugate acid. Understanding how buffers work is important for calculating the pH of solutions that contain both a weak acid and its salt, as seen in the given problem.

Solve an equilibrium problem (using an ICE table) to calculate the pH of each solution. a. a solution that is 0.195 M in HC2H3O2 and 0.125 M in KC2H3O2 b. a solution that is 0.255 M in CH3NH2 and 0.135 M in CH3NH3Br