A 500.0 mL sample of water was equilibrated with excess solid barium chromate, BaCrO₄, at 25 °C. After filtration to remove undissolved material, the water was evaporated to dryness, leaving 3.58 mg of dissolved BaCrO₄ as residue. The formula mass of BaCrO₄ is 253.32 g mol⁻¹.
(a) Determine the molar solubility of BaCrO₄ in water at 25 °C.
(b) Using the dissolution stoichiometry of BaCrO₄, express the equilibrium ion concentrations in terms of the molar solubility calculated in part (a).
(c) Calculate the value of Ksp for BaCrO₄ at 25 °C, reporting the answer to an appropriate number of significant figures.