19.3. Solubility Equilibrium http://www.ck12.org
- The Ks pof a compound can be calculated from its solubility (g/L) or molar solubility (mol/L). Known Ks p
values can be used to calculate the solubility of a compound. - When two solutions are mixed, a precipitate may be produced. The starting ion concentrations are used to
calculate the ion product, which is then compared to the Ks p. If the ion product is greater than the value of
Ks p, a precipitate will form. - The common ion effect describes a reduction in the solubility of a salt that results from the addition of an ion
that is common to both the original solution and the salt being added.
Lesson Review Questions
Reviewing Concepts
- Explain what the following statement means: All ionic compounds are strong electrolytes, no matter how
soluble. - What is the relationship between a compound’s solubility and its solubility product constant?
- Write the solubility product constant (Ks p) expression for the following compounds.
a. NiS
b. Ag 2 CO 3
c. Fe 3 (PO 4 ) 2 - Use the table above (Table19.5) to rank the following salts from most to least soluble.
a. AgBr
b. BaSO 4
c. ZnS
d. PbCO 3 - How does the addition of lead(II) ions affect the solubility of lead(II) chloride in water?
Problems
- The molar solubility of copper(I) bromide, CuBr, is 2.0× 10 −^4 M. Calculate the solubility of CuBr in g/L.
- Calculate Ks pfor the following compounds from the given solubilities at 25°C.
a. SrCO 3 , 5.9× 10 −^3 g/L
b. Ag 2 SO 4 , 4.74 g/L
c. Cr(OH) 3 , 3.4× 10 −^6 g/L - What is the concentration of lead(II) ions and iodide ions in a saturated solution of lead(II) iodide at 25°C?
Refer to the table above (Table19.5) for the Ks p. - Use the Ks pvalues listed above (Table19.5) to calculate the solubility in g/L of the following compounds.
a. Ca 3 (PO 4 ) 2
b. PbSO 4
c. Ca(OH) 2 - Calculate the ion product of silver bromide when 100.0 mL of 0.0020 M AgNO 3 is mixed with 100.0 mL of
1.0× 10 −^4 M KBr. Will a precipitate of AgBr form when the solutions are mixed? - Determine the concentration of lead(II) ions in 1.00 L of a saturated solution of PbF 2 to which 0.025 mol of
fluoride ions has been added. The Ks pof PbF 2 is 4.1× 10 −^8.