1. Phosphoric acid (H3AsO4) is a triprotic acid (the last three protons can dissociate). Define the Ct for this acid. Demonstrate by derivation that the 's are as given. Hint: start from the definition of Ct. Give also the values of the alphas if the pH is A. H3PO4Ka1=7.24103H2PO4+H+;H2PO4Ka2=6.31108HPO42+H+;HPO42Ka3=4.271013PO43+H+0=Ct,PO4[H3PO4]=([H+]3+[H+]2Ka1+[H+]Ka1Ka2+Ka1Ka2Ka3)[H+]31=Ct,PO4[H2PO4]=([H+]3+[H+]2Ka1+[H+]Ka1Ka2+Ka1Ka2Ka3)[H+]2Ka12=Ct,PO4[HPO42]=([H+]3+[H+]2Ka1+[H+]Ka1Ka2+Ka1Ka2Ka3)[H+]Ka1Ka22=Ct,PO4[PO43]=([H+]3+[H+]2Ka1+[H+]Ka1Ka2+Ka1Ka2Ka3)Ka1Ka2Ka3A=6.95