1. Formic acid, HFor, has a Ka value equal to about 1.8 X 10^-4. A student is asked to prepare a buffer having a pH of 3.40 from a 0.10 M HFor and a 0.10 M NaFor solution. How many milliliters of the NaFor solution should she add to 20 mL of the 0.10 M HFor to make the buffer?
2. When 5 drops of 0.10 M NaOH were added to 20 mL of the buffer in problem 3, the pH went from 3.40 to 3.43. Write a net ionic equation to explain why the pH didn't go up to about 10, as it would have if that amount of NaOH were added to distilled water or to 20 mL 0.00040 M HCl, which also would have a pH of 3.40.