Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.100 M phosphoric acid solution.

Question

pKa1 = 2.16
pKa2 = 7.21
pKa3 = 12.32

[H3PO4] = ?
[H2PO4-] = ?
[HPO42-] = ?
[PO43-] = ?
[H+] = ?
[OH-] = ?
pH =?