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:

Direct Benefits

Immediate advantages gained by individuals from engaging in certain behaviors, such as increased survival or reproductive success.

Secondary Helpers

Individuals that assist in the care and raising of offspring that are not their own, typically observed in social animal species.

Breeders

Individuals within a population that are of reproductive age and actively participate in mating and producing offspring.

Direct Benefits

Benefits that directly improve the fitness of an individual receiving them, often in the context of mate choice, including improved nutrition, protection, or resources.