Triprotic Acid Question?

Question

I am having some trouble with triprotric acids, so I was hoping someone could help me. My teacher gave the following example, and I am quite stumped, any help would be appreciated.
The question is: Citric acid (C6H5O7H3) is a troprotic acid because it has three acidic hydrogen ions to donate. Write the 3 equations that would describe how citric acid would react with water and donate its hydrogen ions.

Any help you can give would be appreciated. Thanks

Answer 1

Formula of citric acid is C6H8O7 our top contributor lost it on this one ...

Anyway
H3C6H5O7 + H2O = H2C6H5O7^(-) + H3O^(+)
H2C6H5O7H2- + H2O = HC6H5O7^(2-) + H3O^(+)
HC6H5O7H^(2-) + H20 = C6H5O7^(3-) + H3O^(+)

Answer 2

In general, acid + water <---> H3O+ + conjugate base

C6H5O7H3 + H2O <---> H3O(1+) + C6H5O7H2(1-)
This is a weak acid equilibrium, with its own constant K1

C6H5O7H2(1-) + H2O <---> H3O(1+) + C6H5O7H1(2-)
Equilbrium constant K2

C6H5O7H1(2-) + H2O <---> H3O(1+) + C6H5O7(3-)
Equilibrium constant K3

For triprotic acids, K1 > K2 > K3

Answer 3

Citric acid is actually H3C6H6O7 (your teacher forgot the H on the -OH group).

H3C6H6O7 + H2O ===> H3O+ + H2C6H6O7-

H2C6H6O7- + H2O ===> H3O+ + HC6H6O7=

HC6H6O7= + H2O ===> H3O+ + C6H6O7^3-