The next three (3) problems deal with the titration of 431 mL of 0.501 M carbonic acid (H2CO3) (Ka1 = 4.3 x 10-7, Ka2 = 5.6 x 10-11) with 1.7 M KOH.

What is the pH of the solution at the 2nd equivalence point?

What will the pH of the solution be when 0.2045 L of 1.7 M KOH are added to the 431 mL of 0.501 M carbonic acid?

How many mL of the 1.7 M KOH are needed to raise the pH of the carbonic acid solution to a pH of 6.561?