The solutions shown represent various points in the titration of the weak acid HA with NaO...

The solutions shown represent various points in the titration of the weak acid HA with NaOH. (For clarity, the sodium ions and water molecules are not shown.)

(a) Which diagram corresponds to the beginning of the titration, prior to the addition of any NaOH?

(c) Which diagram corresponds to the equivalence point of the titration? (Ignore salt hydrolysis.)

(d) Which diagram illustrates the solution after the equivalence point, when excess NaOH has been added?

(d) Which diagram corresponds to the point at which the pH is equal to the pKa of the weak acid?