Consider \(100.0 \mathrm{~mL}\) of a \(0.100 \mathrm{M}\) solution of \(\mathrm{H}_{3}\mathrm{~A}\) \(\left(K_{\mathrm{a}_{1}}=1.5 \times 10^{-4}, K_{\mathrm{a}_{2}}=3.0 \times 10^{-8}, K_{\mathrm{a}_{3}}=5.0 \times 10^{-12}ight)\).

a. Calculate the \(\mathrm{pH}\) of this solution.

b. Calculate the \(\mathrm{pH}\) of the solution after \(10.0 \mathrm{~mL}\) of \(1.00 \mathrm{M} \mathrm{NaOH}\) has been added to the original solution.

c. Calculate the \(\mathrm{pH}\) of the solution after \(25.0 \mathrm{~mL}\) of \(1.00 \mathrm{M} \mathrm{NaOH}\) has been added to the original solution.