Applications of Aqueous Equilibrium (Show work and Answer)

Question

At 25^oC, 7.9 E^-4 g of BaCO_3(s) will dissolve in 100. mL of water.

a. Write the equation for the dissociation of BaCO_3(s) in water.

b. Calculate the solubility, in moL/L, of BaCO_3(s) in water at 25^oC.

c. Calculate the value of the solubility-product constant, K_sp, for BaCO_3(s) at 25^oC.

Answer 1

a). BaCO₃(s) <==> Ba²⁺(aq) + CO₃^2-(aq)

b). molar mass BaCO3 = 197 g/mol

7.9x10^-4 g x 1 mol / 197 g /0.1 L = 4.0x10^-5 mol/L

c). Ksp = [Ba²⁺][CO₃^2-] = (4.0x10^-5)²

Ksp = 1.6x10^-9