Passage II (Questions 9-12)

A chemist wishes to separate a mixture containing 0.1 M Zn2+ ions and 0.1 M Pb2+ ions. She decides to use the difference in Ksp's (see Table 1) to effect the separation.

The chemist predicts the following results (Table 2).

In preparing sulfide solutions, the chemist makes use of the following relation for the H2S system:

[H+]2[S2-] =1 x 10-23