100 ml of 0.1M His solution at pH = 0.5 is titrated with 0.1M NaOH until the pH reaches 13. The pKa values for His are 1.8, 6.0 and 9.2. Using this information:
(a) Sketch the titration curve, being sure to label the pH and volume axes. Indicate clearly the volume of 0.1M NaOH required to raise the pH to the pI of His, the volume of 0.1M NaOH required to raise the pH to values equal to each pKa, and the volume required to convert all of the ionizable group to the conjugate base form.
(b) Calculate the pH of the solution after the addition of 30ml of 0.1M NaOH.
(c) Draw the structure of the form is His predominating in solution at neutral pH.