A) how many mL of NaCHO2 solution should she add to 20.0 mL of the 0.10 M HCHO2 to make a buffer?
B) write a net ionic equation to explain why the pH didn't go up to about 10
3. Formic acid, HCHO2, has a Ka 1.8 X 104. A student is asked to prepare a buffer having a pH of 3.40 from a 0.10 M HCHO2 and a 0.10 M NaCHO2 (sodium formate; formate ion is the conjugate base). How many milliliters of the NaCHO2 solution should she add to 20.0 mL of the 0.10 M HCHO2 to make the buffer? mL 4. 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 20.0 mL of 0.00040 M HCI, which also would have a pH of 3.40.
