A Compound (not specified) has 2 ionizable groups. One is at pKa 4.2 and the other pKa is between 7 and 10. If you have 10.0 mL of a 1.0M solution at a pH of 8.17 and you add 10.0mL of 1.0M HCl which changes the pH to 4.2 what is the second pKa?
I tried working this problem out a few...