For the diprotic weak acid H2A, a1=3.4106 and a2=6.1109.

What is the pH of a 0.0500 M solution of H2A? What are the equilibrium concentrations of H2A and A2 in this solution?

Express a1 in terms of , and then show the simplified expression (when is assumed to be negligible compared to to the initial concentration).

a1=/ =/

numerator in complete expression:

denominator in complete expression:

numerator in simplified expression:

denominator in simplified expression:

Also, give the numerical value of using the appropriate approximation. What is the pH of the solution if you stopped here?

x:

pH: