Question

The following concentrations are found in mixtures of ions in equilibrium with slightly soluble solids. From the concentrations given, calculate Ksp for each of the slightly soluble solids indicated:

a) MgCO3 with [Mg2+] = 2.5×10−4M and [CO3²-] = 5.0×10−4M
b) CaSO4 with [Ca2+] = 3.0×10−5M and [SO4²-] = 6.0×10−6M
c) Ag2CO3 with [Ag+] = 1.2×10−8M and [CO3²-] = 2.4×10−8M
d) Pb(IO3)2 with [Pb2+] = 4.8×10−6M and [IO3-] = 1.6×10−5M

Answer 1

To calculate Ksp for slightly soluble solids, multiply the concentrations of the ions involved in the equilibrium. For example, for MgCO3, Ksp = [Mg2+][CO3²-].

Step-by-step explanation:

The Ksp (solubility product constant) is a measure of the solubility of a slightly soluble solid in a solution. It represents the product of the concentrations of the ions in equilibrium with the solid.

To calculate Ksp, multiply the concentrations of the ions involved in the equilibrium.

For example:

1. For MgCO3 with [Mg2+] = 2.5×10−4M and [CO3²-] = 5.0×10−4M, Ksp = [Mg2+][CO3²-] = (2.5×10−4)(5.0×10−4).
2. For CaSO4 with [Ca2+] = 3.0×10−5M and [SO4²-] = 6.0×10−6M, Ksp = [Ca2+][SO4²-] = (3.0×10−5)(6.0×10−6).
3. For Ag2CO3 with [Ag+] = 1.2×10−8M and [CO3²-] = 2.4×10−8M, Ksp = [Ag+][CO3²-] = (1.2×10−8)(2.4×10−8).
4. For Pb(IO3)2 with [Pb2+] = 4.8×10−6M and [IO3-] = 1.6×10−5M, Ksp = [Pb2+][IO3-] = (4.8×10−6)(1.6×10−5).