Perform these calculations for nickel(II) carbonate. (a)...

Perform these calculations for nickel(II) carbonate. (a) With what volume of water must a precipitate containing $\mathrm{NiCO}_{3}$ be washed to dissolve 0.100 $\mathrm{g}$ of this compound? Assume that the wash water becomes saturated with $\mathrm{NiCO}_{3}\left(K_{\mathrm{sp}}=1.36 \times 10^{-7}\right)$ (b) If the NiCO_ were a contaminant in a sample of $\operatorname{CoCO}_{3}\left(K_{\mathrm{sp}}=1.0 \times 10^{-12}\right),$ what mass of $\mathrm{CoCO}_{3}$ would have been lost? Keep in mind that both NiCO_ a and CoCO_ dissolve in the same solution.

Perform these calculations for nickel(II) carbonate. (a) With what volume of water must a precipitate containing $\mathrm{NiCO}_{3}$ be washed to dissolve 0.100 $\mathrm{g}$ of this compound? Assume that the wash water becomes saturated with $\mathrm{NiCO}_{3}\left(K_{\mathrm{sp}}=1.36 \times 10^{-7}\right)$
(b) If the NiCO_ were a contaminant in a sample of $\operatorname{CoCO}_{3}\left(K_{\mathrm{sp}}=1.0 \times 10^{-12}\right),$ what mass of $\mathrm{CoCO}_{3}$ would have been lost? Keep in mind that both NiCO_ a and CoCO_ dissolve in the same solution.

Key Concepts

Solubility Product Constant (Ksp)

The solubility product constant (Ksp) defines the equilibrium between a sparingly soluble ionic solid and its dissolved ions in a saturated solution. It is a crucial parameter for determining the solubility of compounds. A lower Ksp value indicates that the salt is less soluble in water. This concept allows the calculation of ion concentrations in a saturated solution, and thereby, the amount of solid that will dissolve under equilibrium conditions.

Molar Solubility Calculation

Molar solubility refers to the number of moles of a compound that can dissolve per liter of solvent until saturation is reached. It is derived from the Ksp expression by setting up an equilibrium for the dissolution of the solid. Once the molar solubility is determined, calculations involving the number of moles or mass of the solute that can dissolve in a given volume of solution can be performed, which is critical in titration or washing processes.

Equilibrium and Saturated Solutions

Understanding chemical equilibrium, especially in the context of saturated solutions, is essential when dealing with dissolving salts. A saturated solution is one in which no more solute can dissolve at a given temperature because the solution is in dynamic equilibrium. This concept is fundamental when determining how much solvent is necessary to dissolve a given mass of solute, ensuring that the solution reaches but does not exceed saturation.

Contaminant Analysis in Precipitation

When multiple salts are present in a solution, especially when one is a contaminant in a precipitate, it is vital to analyze how much of the contaminant might dissolve. The effect of one compound’s dissolution on another often relies on their respective solubilities and Ksp values. This analysis is important in evaluating losses of material due to selective dissolution during washing or separation processes, ensuring proper recovery or accounting of each component.