1. The problem statement, all variables and given/known data Calculate the pH at the equivalence point for the titration of 0.20 M NH3 with 0.20 M HCl? Kb of ammonia is 1.8e-5 This is just a old test I am going over, I managed to get a pH of 4.98. but that is not right the right answer is 5.12 and I cant figure out why. I would assume you could use the henderson equation but I only get 4.98 which is wrong. Any help?