Calculate the pH at the halfway point and at the equivalence point for each of the following titrations.
a) 100.0 mL of 0.70 M HC7H5O2 (Ka=6.4×10−5) titrated by 0.10 M NaOH.
b) 100.0 mL of 0.70 M C2H5NH2 (Kb=5.6×10−4) titrated by 0.20 M HNO3.
c. 100.0 mL of 0.80 M HCl titrated by 0.25 M NaOH.