Assuming Equal Concentrations of Conjugate Base and Acid, Which One

question 67

Multiple Choice

Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 9.2-9.3

• A) CH₃COONa / CH₃COOH (K_a = 1.8 * 10^-5)
• B) NH₃ / NH₄Cl (K_a = 5.6 * 10^-10)
• C) NaOCl / HOCl (K_a = 3.2 * 10^-8)
• D) NaNO₂ / HNO₂ (K_a = 4.5 * 10^-4)
• E) NaCl / HCl