Question

Okay so my lecturer has this in our slides and there are no notes just a heading saying speaciation, I have tried google and everything I have read does not include pH in their question. Please help me

Calculate the equilibrium concentrations of the different species in a 0.100 M fumaric acid solution at pH 2.00.For fumaric acid, pKa1 = 3.053 and pKa2 = 4.494

I would start of with:
Ka= antilog(pka)

H2M ----- 2H+ + M-
HM- ----- H+ + M-
Then: Ka1 = [H][M]/H2M
Let H and M equal X and let H2M equal 0.1-×
Ka2 = [H][M]/HM

Am I suppose to use the pH as the H+ species
Like [H+] = antilog [pH]

Help please!

Answer 1

http://www.speciation.net/Public/Document/2003/09/11/495.html

Yes, use pH as the H+ species. Yes, like that.

Answer 2

Then if H+ equals antilog pH, M- would also be equal to H+ , so then what will I be solving for? Because H2M species is given

Sorry if this is a stupid question, I really don't know

Thanks you!!