Consider the diprotic acid H2A with K1 =1.00 X 10-4

Question

and K2 =
1.00 X 10-8
. Find the pH and concentrations of H2A, HA-
, and A2-
in:
(a) 0.100 M H2A; (b) 0.100 M NaHA; (c) 0.100 M Na2A.

Answer 1

(a) pH = 2.00; [H2A] = 0.100 M; [HA-] = 1.00 x 10-4 M; [A2-] = 1.00 x 10-8 M

(b) pH = 4.00; [H2A] = 1.00 x 10-4 M; [HA-] = 0.100 M; [A2-] = 1.00 x 10-8 M

(c) pH = 6.00; [H2A] = 1.00 x 10-8 M; [HA-] = 1.00 x 10-4 M; [A2-] = 0.100 M