Question

A mixture contains 1.0 x 10²³ Cu²+ and 1.0 x 10²³ Mn²+ and is saturated with 0.10 M H₂S. Determine the pH where CuS precipitates but MnS does not precipitate. Ksp for CuS = 5.8 x 10⁻⁴⁵ and Ksp for MnS = 2.3 x 10⁻¹³.

Answer 1

To determine the pH where CuS precipitates but MnS does not precipitate, we need to compare the Ksp values for CuS and MnS to the concentration of H+ ions in the solution.

Step-by-step explanation:

To determine the pH where CuS precipitates but MnS does not precipitate, we need to compare the Ksp values for CuS and MnS to the concentration of H+ ions in the solution. CuS will precipitate when the concentration of Cu2+ ions exceeds the solubility product constant (Ksp) for CuS. Similarly, MnS will precipitate when the concentration of Mn2+ ions exceeds the Ksp for MnS.

The Ksp values for CuS and MnS are given, and we know that the reaction of H2S with water produces H3O+ ions. So, to determine the pH at which only CuS precipitates, we need to find the concentration of Cu2+ ions using the information given and calculate the corresponding pH.