For a triprotic acid H2PO4. Ka1=7.11e-3, Ka2=6.32e-8 and Ka3=7.1e-13. 50mL each of 0.05F CaCl2 and 0.05F phosphoric acid were mixed. Ksp CaHPO4=2.6e-7.

Question

a) Would CaHPO4 precipitate when phosphoric acid and calcium chloride were mixed together?
b) List all species (ions, molecules, solids etc) expected to be present in the system.
c) Write the set of equations that can be used to solve for the concentrations of all the species in the system.
Thank you in advance for your help :)

Answer 1

Didn't I do one of those "list all species of H3PO4" for you recently? I don't want to write all of that stuff again. Look at your notes (you do take notes here I would think). What can you do on your own?

Answer 2

No, I am sorry. This is the first time I have posted this question. Where can I find the similar question?

Answer 3

I found it.
http://www.jiskha.com/display.cgi?id=1425612744

Answer 4

Thank you for your help. I think the differences between my question and the question that you sent me is that: mine is the mixture of H3PO4 and CaCl2 while the other is just dissociation of H3PO4. For b) I just write H3PO4 + H20 -> H2PO4- +H3O+
H2PO4- +H20 -> HPO4- +H3O+
HPO4 2- + H2O -> PO43- +H3O+
So what should I write for the reaction between H3PO4 and CaCl2

Answer 5

i am still having issues setting this exact problem up can you please help