Which of the following acids should be used to prepare a buffer with a pH of 4.5? A)HOC ₆H ₄OCOOH, K _a = 1.0 × 10 ⁻³ B)C ₆H ₄(COOH)₂, K _a = 2.9 × 10 ⁻⁴ C)CH ₃COOH, K _a = 1.8 × 10 ⁻⁵ D)C ₅H ₅O ₅COOH, K _a = 4.0 × 10 ⁻⁶ E)HBrO, K _a = 2.3 × 10 ⁻⁹

Question

Quizplus · Accepted Answer

To prepare a buffer with a pH of 4.5, we need an acid with a pKa close to 4.5. Among the given options, the acid with the closest pKa value to 4.5 is CH3COOH (acetic acid) with a pKa of 4.76. The correct option is C, which is the formula for acetic acid.

Which of the Following Acids Should Be Used to Prepare