Which of the following indicators would be most suitable for the titration of 0.10 M (CH₃)₃N(aq) with 0.10 M HClO₄(aq)? For trimethyamine,PK_b = 4.19.

Question

Quizplus · Accepted Answer

The suitable indicator for titration of a weak base with a strong acid should have a pK in the range of the expected pH transition of the reaction. For the reaction between trimethylamine and HClO, the expected pH transition is close to the pK of trimethylamine, which is 4.19. Therefore, the most suitable indicator would be one with a pK close to 4.19, which is bromocresol green with a pK of 4.7. The other indicators have pK values that are too high or too low for this titration.

Which of the Following Indicators Would Be Most Suitable for the Titration