A 0.10-mol sample of a diprotic acid, H2A, is dissolved in 250 mL of water. The Ka1 of this acid is 1.0 x 10-5 and Ka2 is 1.0 x 10-10. Calculate the concentration of A2- in this solution.
A. 1.0 x 10-5 M
B. 2.0 x 10-3 M
C. 4.0 x 10-6 M
D. 1.0 x 10-10 M
E. 0.40 M