The following compounds are available as 0.10 M aqueous solutions: pyridine (pK_b = 8.82),triethylamine (pK_b = 3.25),HClO₄,phenol (pK_a = 9.96),HClO (pK_a = 7.54),NH₃ (pK_b = 4.74)and NaOH.Identify two solutions that could be used to prepare a buffer with a pH of approximately 5. A)pyridine and HClO₄ B)triethylamine and HClO₄ C)phenol and NaOH D)HClO and NaOH E)HClO and NH₃

Question

Quizplus · Accepted Answer

Pyridine (a weak base) and HClO4 (a strong acid) can form a buffer solution with a pH around 5, as the pKa of pyridinium ion (conjugate acid of pyridine) is approximately 5.18.

The Following Compounds Are Available as 0