試題詳解

6. You analyze for pyridine (K, is approximately 10^-9) by dissolving 0.1000 g of the complex in 100 mL of H₂O and titrating with a 0.01 M HCI solution. Which of the following indicators should be used to detect the endpoint? (Assume that the initial concentration of pyridine is approximately 0.01 M.)
(A) bromophenol blue, pH range of color change = 3.0-4.6
(B) methyl red, pH range of color change = 4.8-6.0
(C) bromothymol blue, pH range of color change = 6.0-7.6
(D) thymol blue, pH range of color change = 8.0-9.6
(E) alizarin yellow, pH range of color change = 10.1-12.0