I am giving a titration curve of a weak base and strong acid. The pH on the y scale is from 0-14 and the volume of titrant in mL is from 0-34. It looks like the equivalene point is around 22? The question is:

Question

"The above titration curve was obtained when a 10 mL sample of a 0.45 M base was titrated with an acid. What is the approximate molarity of the acid used?" (Assume a 1:1 molar ratio)

Answer 1

You must mean 22 mL?(not pH of 22). Then
mL acid x M acid = mL base x M base

Answer 2

Yes I meant 22mL. How would I go about solving for the Kb?

Answer 3

At the half way point to the equivalence (that would be 22/2 = 11 mL), pH at that point will be pKb