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

question 101

Multiple Choice

Which of the following acids (listed with K_a values) and their conjugate base would be the best choice to make a buffer with a pH of 5.20?

• A) C₆H₅COOH, 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

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