The solubility of two slightly soluble salts of M2 + , MA and MZ2, is the same, 4 * 10-4 mol/L. (c) If you added an equal volume of a solution saturated in MA to one saturated in MZ2, what would be the equilibrium concentration of the cation, M2+?

Verified step by step guidance

1. Identify the initial concentrations of M2+ in both solutions. Since the solubility of MA and MZ2 is given as 4 * 10^-4 mol/L, the concentration of M2+ from MA is 4 * 10^-4 mol/L.
2. Determine the concentration of M2+ from MZ2. For every mole of MZ2 that dissolves, it produces 1 mole of M2+ and 2 moles of Z-. Therefore, the concentration of M2+ from MZ2 is also 4 * 10^-4 mol/L.
3. Calculate the total initial moles of M2+ before mixing. Since the volumes are equal, add the moles of M2+ from both solutions together.
4. Determine the total volume of the mixture. Since equal volumes of both solutions are mixed, the total volume is double the volume of one of the solutions.
5. Calculate the equilibrium concentration of M2+ in the mixture. Divide the total moles of M2+ by the total volume of the mixture to find the new concentration of M2+.

Key Concepts

Solubility Product Constant (Ksp)

The solubility product constant (Ksp) is a numerical value that represents the equilibrium between a solid and its ions in a saturated solution. For slightly soluble salts, Ksp is calculated from the concentrations of the ions in solution at equilibrium. Understanding Ksp is crucial for predicting how changes in concentration affect solubility and ion concentrations in mixed solutions.

Common Ion Effect

The common ion effect describes the decrease in solubility of a salt when a common ion is added to the solution. This phenomenon occurs because the addition of a common ion shifts the equilibrium position, reducing the concentration of the dissolved ions. In the context of the question, adding a saturated solution of MA to MZ2 introduces a common ion, which will influence the equilibrium concentrations of M2+.

Equilibrium Concentration

Equilibrium concentration refers to the concentration of reactants and products in a chemical reaction at equilibrium, where the rates of the forward and reverse reactions are equal. In this scenario, calculating the equilibrium concentration of M2+ involves considering the contributions from both salts and how they interact when mixed. This requires applying the principles of Ksp and the common ion effect to find the new equilibrium state.