A titration was performed between 25 mL of 0.100 M NH3 and 0.100 M HCl. Calculate the pH of NH3 solution at the following points during the titration.
Prior to addition of any HCl
After addition of 12 mL of 0.100M HCl
At the equivalence point
After the addiation of 31 mL of 0.100M HCl