For each pair of compounds, use Ksp values to determine which has the greater molar solubility: (b) PbCO3 or BaCrO4.

Verified step by step guidance

1. Identify the Ksp (solubility product constant) values for both PbCO3 and BaCrO4 from a reliable source such as a chemistry textbook or database.
2. Write the dissolution equations for each compound. For PbCO3, the equation is PbCO3(s) ⇌ Pb^2+(aq) + CO3^2-(aq). For BaCrO4, the equation is BaCrO4(s) ⇌ Ba^2+(aq) + CrO4^2-(aq).
3. Express the molar solubility (s) for each compound using the dissolution equations. For PbCO3, if s is the molar solubility, then [Pb^2+] = s and [CO3^2-] = s. For BaCrO4, [Ba^2+] = s and [CrO4^2-] = s.
4. Set up the Ksp expression for each compound using the concentrations derived from the molar solubility. For PbCO3, Ksp = [Pb^2+][CO3^2-] = s * s = s^2. For BaCrO4, Ksp = [Ba^2+][CrO4^2-] = s * s = s^2.
5. Compare the calculated s values (molar solubility) for each compound. The compound with the higher s value has the greater molar solubility.

Key Concepts

Solubility Product Constant (Ksp)

The solubility product constant (Ksp) is an equilibrium constant that quantifies the solubility of a sparingly soluble ionic compound. It is defined as the product of the molar concentrations of the ions, each raised to the power of their coefficients in the balanced dissolution equation. A higher Ksp value indicates a greater solubility of the compound in water.

Molar Solubility

Molar solubility refers to the maximum concentration of a solute that can dissolve in a given volume of solvent at equilibrium. It is typically expressed in moles per liter (M). To compare the molar solubility of two compounds, one can derive it from their Ksp values, allowing for a direct comparison of how much of each compound can dissolve in solution.

Dissociation of Ionic Compounds

When ionic compounds dissolve in water, they dissociate into their constituent ions. The extent of this dissociation affects the Ksp and, consequently, the molar solubility. Understanding the stoichiometry of the dissociation reaction is crucial for calculating the Ksp and determining the molar solubility of each compound, as different compounds yield different numbers of ions upon dissolution.