2. Given: Ka of H3PO4 is 6.90 X 10-3, Ka of H2PO4- is 6.30 x 10-8 and Ka of 4.20 x 10-13. A 0.250 M phosphate buffer has a pH of 3.00.

a. What is the formula for the acid in this buffer? _________

b. What is the formula for the base in this buffer? _________

c. Calculate the ratio [A-]/[HA] for this buffer solution at pH 3.00.

d. If the 0.250 M phosphate buffer solution had a pH of 12.10, what would the formula of the acid in the buffer solution? __________

What would be the formula for the base in the buffer solution at pH 12.10? __________ Calculate the ratio of [A-]/[HA] in the buffer at pH 112.10. D please