# Solution: Pyradine (C6H5N) is a weak organic base with a K b of 1.7x10...

###### Question

Pyradine (C6H5N) is a weak organic base with a K b of 1.7x10-9. Suppose you were to titrate 25.0 mL of a 0.100 M aqueous solution of pyridine with a 0.100 M HCl solution.

a. What is the pH at the equivalence point?

b. The Ka of the acid-base indicator 2,3-dinitrophenol is around 6.69 x 10 -5, and the Ka of the acid-base indicator thymolphthalein is approximately 1.26x10-10. If you had to choose between these two indicators for your titration above, which would you choose?