What Is the Composition of the Precipitate Formed When H₂S

Multiple Choice

What is the composition of the precipitate formed when H₂S gas is bubbled through 1.0 litre of a solution of 0.010 M Zn²⁺, 0.010 M Pb²⁺, and 0.010 M Mn²⁺, buffered at pH 2.0, until 0.10 mol of H2S has been added? [Ksp values are: ZnS: 1.6 × 10^-23; MnS: 7.0 × 10^-16; PbS: 7.0 × 10^-29. For H₂S, Ka1 = 1.0 × 10^-7; Ka₂ = 1.3 × 10^-13.

A) only ZnS
B) only MnS
C) only PbS
D) only MnS and PbS
E) only ZnS and PbS