What Is the Composition of the Precipitate Formed When H₂S

question 52

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

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Definitions:

Evolutionary Psychology

A field of psychology that examines psychological traits, such as memory and perception, as adaptations to evolutionary processes.

Genes

Segments of DNA that are responsible for hereditary characteristics and serve as the basic units of heredity.

Dependent Variables

Variables in experimental research that are expected to change as a result of manipulation of independent variables; they are the outcomes measured by the researcher.

Independent Variables

In an experiment, the variable that is manipulated or altered to examine its effect on a dependent variable.