Which of the following acids (listed with K_a values)and their conjugate base would form a buffer with a pH of 2.34? A)HC₇H₅O₂,K_a = 6.5 × 10^-5 B)HF,K_a = 3.5 × 10^-4 C)HClO,K_a = 2.9 × 10^-8 D)HCN,K_a = 4.9 × 10^-10 E)HClO₂,K_a = 1.1 × 10^-2

Question

Quizplus · Accepted Answer

A buffer is a solution that can resist changes to its pH when small amounts of acid or base are added to it. For a buffer to be effective, it must contain both a weak acid and its conjugate base in roughly equal amounts. The pH of a buffer is determined by the Ka of the weak acid and the concentration of the acid and its conjugate base.

To determine which acid and conjugate base pair would form a buffer at a pH of 2.34, we need to find an acid with a Ka value close to 10^-2.34 (which is about 4.3x10^-3) and its corresponding conjugate base.

Looking at the given options, only HClO has a Ka value close to 4.3x10^-3, and its conjugate base, ClO-, is included in the formula for HClO2. Therefore, option E (HClO2/ClO-) is the correct choice for this buffer.

Which of the Following Acids (Listed with Ka Values)and Their

Which of the Following Acids (Listed with K_a Values)and Their