Question

10. A weak acid with an initial pH of 3.2 was titrated with a strong base. 15 mL of 0.1 M NaOH was added to the acid to reach the equivalence point at a pH of 8.6. What would you expect the approximate pH of the analyte to be after the first 5 mL of 0.1 M NaOH was added?

8.6

3.4

5.1

7.2

Answer 1

I would choose 5.1. If one third of the base is added (in which the whole 15ml was utilized to bring to a basic state of 8.6), it must be 5.1, as the other answers are mathematically impossible.