Hi, I have been trying to solve this exercise:

Check that the pH of these two solutions for a concentration of 0.01M is 4.6 and 9.6. Givens: H2P04 pka1=2.15, pka2=7.2 and pka3=12.4

I managed to prove that the 1st pH is 4.6 but I have no clue how to get the 9.6 one? Is this something anyone can help me to understand how to do it?

Thanks!