Can anyone give me a push in the right direction, how do I calculate the concentration of all species present in a solution with 0.3M NaH2PO4. So the concentration of H3PO4, H2PO4 -, HPO4 2-, PO4 3- and H30+.
I already know how to approximate the ph for an amphiprotic, pH=1/2(pKa1+pKa2). Should I use the [H30+] from this calculation in any way?
I know how to set up equilibrium equations and tables, but starting with the deprotonated form of a polyprotic acid confuses me.
I cant figure out in what order i need to calculate things.
For phosphoric acid Ka1=7.6×10^-3 Ka2=6.2×10^-8 Ka3=2.1×10^-13