Aniline hydrochloride,[C6H5NH3]Cl, is a weak acid. (Itsconjugate base is the weak base aniline,C6H5NH2.) The acid can be titratedwith a strong base such as NaOH:
C6H5NH3+(aq) +OH -(aq) C6H5NH2(aq)+ H2O(l)

Assume 46.2 mL of 0.100 M anilinehydrochloride is titrated with 0.185 M NaOH.(Ka for aniline hydrochloride is2.4 multiplied by 10-5.)
2.81 is the pH of the[C6H5NH3]Cl solution before thetitration begins.

8.72 is the pH at the equivalence point

4.62 is the pH at the midpoint of the titration

(e) Calculate the pH of the solution afteradding 10.0, 20.0, and 30.0 mL of the base.