Chapter 15, Problem 87AE

When a diprotic acid, H₂A. is titrated with NaOH, the protons on the diprotic acid are generally removed one at a time, resulting in a pH curve that has the following generic shape:

1. a. Notice that the plot has essentially two titration curves. If the first equivalence point occurs at 100.0 mL NaOH added, what volume of NaOH added corresponds to the second equivalence point?
2. b. For the following volumes of NaOH added, list the major species present after the OH reacts completely.
   1. i. 0 mL NaOH added
   2. ii. between 0 and 100.0 mL NaOH added
   3. iii. 100.0 mL NaOH added
   4. iv. between 100.0 and 200.0 niL NaOH added
   5. v. 200.0 mL NaOH added
   6. vi. after 200.0 mL NaOH added
3. c. If the pH at 50.0 mL NaOH added is 4.0 and the pH at 150.0 mL NaOH added is 8.0, determine the values K_a1 and K_a2 for the diprotic acid.