1. Solubility of Salts & Complex Ions

2. Solubility of Salts Precipitation reactions occur when one of the products in a double replacement is a water-_________ compound

3. Predicting Solubility The good guys are ALWAYS soluble #1 NOCHOCLON Alkali metals NO 3 - C2H3O2-C2H3O2- ClO 3 - ClO 4 - NH 4 +

4. Other Ions Halogens are mostly ______; except with Ag, Pb OH- are mostly ______; except with CaBaSr CO 3 2-, PO 4 2-, S 2-, and SO 3 2- are mostly ________.

5. Solubility of Insoluble Salts “Insoluble” means that less than 0.01 mole dissolves per liter SOME still dissolves according to an equilbrium expression.

6. Solubility Product Constant K sp The equilibrium constant that reflects the solubility of a compound –“sp”: solubility product AgBr(s) K sp = 5.4 x10 -13 Appendix J lists K sp values

7. Practice Problems Write the equililibrium expressions for the solid in water. 1) BaF 2 (s) 2) Ag 2 CO 3 (s)

8. Calculating K sp from Solubility In a saturated solution of BaF 2, 0.063 grams of the compound is dissolved in 100 mL. Use this information calculate the K sp for BaF 2. BaF 2 (s) Ba 2+ (aq) + 2F - (aq)

9. Estimating the Salt Solubility from K sp The K sp of Ag 2 CO 3 is 8.5 x 10 -12. What is the concentration of Ag 2 CO 3, Ag +, and CO 3 2- dissolved? Convert Ag 2 CO 3 concentration to g/L.

10. What volume of water is required to dissolve 1 gram of Ag 2 CO 3 ?

11. Solubility & the Common Ion Effect The solubility of a salt is lowered by the presence of a common ion in the solution. (LeChatlier's) Write the reaction and expression for the solubility of Zn(OH) 2.

12. Practice Problem Calculate the solubility in mol/L of Zn(OH) 2 in the presence of 0.010M Zn(NO 3 ) 2, –K sp of Zinc Hydroxide = 3.0 E-17

13. K sp and Q (reaction quotient) Q reflects concentration of ions ___________________. K reflects the concentration of ions __________________. Q = K sp : __________________ Q < K sp : __________________ Q > K sp : __________________

14. Precipitation Reaction If the concentration of Mg 2+ is 1.5x10 -6 M and the concentration of OH - is 1.0x10 -4 M, will precipitation of Mg(OH) 2 occur? K sp = 5.6x10 -12.

15. Precipitation Reaction cont If the concentration of magnesium remains 1.5x10 -6 M, what concentration of the hydroxide ion is needed to precipitate magnesium hydroxide?

16. Precipitation Reactions The value for the Ksp of of AgBr is 5.0E- 13. Write the Ksp expression. A student mixes 10 mL of 1.5 x 10 -4 M AgNO 3 with 2.0 mL of 5.0x10 -4 M NaBr and stirs. What will the student observe? Justify with a calculation.