A concentrated buffer of pH 8.0 is added to an equal volume of a solution that is 0.080 M in each of the ions Zn²⁺, Ni²⁺, and Mn²⁺. The expected precipitate would consist of ________. salt: zinc hydroxide nickel hydroxide manganese hydroxide
Ksp 1.2 × 10^-17 2.0 × 10-¹⁵ 1.9 × 10^-13

Question

Quizplus · Accepted Answer

Since the solution contains equal concentrations of Zn²⁺, Ni²⁺, and Mn²⁺, we can assume that the precipitate will also contain equal amounts of each ion. The Ksp values provided indicate that Mn(OH)₂ has the lowest solubility, so it will precipitate first. Ni(OH)₂ is less soluble than Zn(OH)₂, so it will precipitate next. Therefore, the expected precipitate will consist of Ni(OH)₂ and Zn(OH)₂, making choice (D) the correct answer.

A Concentrated Buffer of PH 8