1. Solubility Equilibrium

2. Solutions Solvent – Solute – Molecular Solution – Organics – Non-metal/non-metal –

3. Ionic Solutions (Electrolytes) – Ionic – Acids – Bases –

4. Electrolytes Ions are attracted to electrodes

5. CuI IBr CO 2 H 2 SO 4 SF 6 Al(OH) 3 SnO 2 CH 3 COOH NH 3 Al 2 (SO 3 ) 3 O 2 Types of Solutes (solutions)

6. CuI (s) ↔ Cu + (aq) + I - (aq) IBr (g) ↔ IBr (aq) CO 2(g) ↔ CO 2(aq) H 2 SO 4 ↔ 2H + (aq) + SO 4 2- (aq) SF 6(s) ↔ SF 6(aq) Al(OH) 3(s) ↔ Al 3+ (aq) + 3OH - (aq) SnO 2(S) ↔ Sn 4+ (aq) + 2O 2- (aq) CH 3 COOH (l) ↔ CH 3 COO - (aq) + H + (aq) NH 3(g) ↔ NH 4 + (aq) + OH - (aq) Al 2 (SO 3 ) 3(s) ↔ 2Al 3+ (aq) + 3SO 3 2- (aq) O 2(g) ↔ O 2(aq) Dissociation Equations

7. Solubility The extent to which a solute is soluble in water at a given temperature. Many types of units. Moles solute L solution Grams solute 100.mL solution %Volume solute Volume solution %Mass solute Mass solution Moles solute kg solvent Moles + charge L solution

8. Saturated Solutions A solution is saturated when the maximum amount (concentration) of solute is dissolved in the solvent at a given temperature. Solubility equilibrium (Saturation) exists when the rate of dissolving = rate of crystallization Some solid must be present.

9. Dissociation Equations Al 2 (SO 3 ) 3(s) ↔ 2Al 3+ (aq) + 3SO 3 2- (aq) Forward is dissociation Reverse is precipitation Both occurring at same rate  Saturated

10. 6.02x10 23 4.72x10 -5 4

11. Solubility and Ion Concentration If 250.mL of saturated NaF solution was evaporated to dryness and found to contain 3.59g NaF. What is the molar solubility?

12. The molar solubility of MgCO 3 is 1.26x10 -3 M. What is this in g/100.0mL.

13. Solubility Curves Which salt is most soluble at 20˚C? If you put 50g KNO 3 in 100g water at 20˚C and heat it, what happens? Is the dissolution of Ce 2 (SO 4 ) 3 endo- or exothermic?

14. Work on Questions… Practice 1abcdef, 2ab, 3a, 4, 8, 11, 13, 14, 16, 17. Assignment handouts #1 and 2

15. Al 2 (SO 3 ) 3(s) ↔ 2Al 3+ (aq) + 3SO 3 2- (aq) 2.4mol of Al 2 (SO 3 ) 3(s) is dissolved and diluted to a volume of 1.0L. What are the ion concentrations?

16. What are the ion concentrations in a solution containing 0.26g Ca(OH) 2 in 500.0mL of solution? Hoop#1 Dissociation Equation

17. Dilution If 25.0mL of 0.010M Br - is added to 15.0mL of 0.13M Cl -, what is the resulting concentration of each ion?

18. What are the concentrations of all ions present when 2.5mL of 0.85M MgCl 2 is added to 8.0mL of 0.55M AlBr 3 ?

19. What are the concentrations of all ions present when 15mL of 0.80M MgCl 2 is added to 80.0mL of 0.35M AlCl 3 ?

20. Work on Questions… 18c, 20df.

21. Predicting Solubility

22. Is PbI 2 expected to precipitate? Would a ppt form if equal volumes of 0.20M KI and Pb(NO 3 ) 2 are mixed? Would a ppt form if equal volumes of 0.20M AgNO 3 and Li 2 S are mixed?

23. Double Replacement Rxns Formula Equations – include all species and (aq) or (s) designations (no ions shown). 2AgNO 3(aq) + Na 2 CO 3(aq) → Ag 2 CO 3(s) + 2NaNO 3(aq) Complete Ionic Equations – show (aq) species as separate ions. 2Ag + (aq) + 2NO 3 - (aq) + 2Na + (aq) + CO 3 2- (aq) → Ag 2 CO 3(s) + 2Na + (aq) + 2NO 3 - (aq)

24. Net Ionic Equations Do not show any spectator ions, only those involved in precipitation. 2Ag + (aq) + 2NO 3 - (aq) + 2Na + (aq) + CO 3 2- (aq) → Ag 2 CO 3(s) + 2Na + (aq) + 2NO 3 - (aq) 2Ag + (aq) + CO 3 2- (aq) → Ag 2 CO 3(s)

25. Work on Questions… Practice 21efghij, 22, 24abc, 25hij. Assignment handout #3

26. Selective Ion Precipitation A qualitative method to determine whether certain ions are present in a solution or not. Let’s assume a sample Ag + and Sr 2+. We would have to ppt one at a time, not both. Cl - SO 4 2- S 2- OH - PO 4 3-

28. Ag + Sr 2+ Salt Cl - SO 4 2- S 2- OH - PO 4 3- Ag + Sr 2+ The anion being added must be added as a soluble salt. Otherwise, there’s no way to add it (there’s no such thing as a lone ion, except in plasma). Step 1: Add ___________ to precipitate ___________ Step 2: Filter to remove any ________ that forms Step 3: Add ___________ to precipitate ___________ Step 4: Filter to remove any ________ that forms

29. How would you analyse a solution that may, or may not, contain Ag +, Ba 2+, and Ni 2+ ? Cl - SO 4 2- S 2- OH - PO 4 3- Step 1: Add ___________ to precipitate ___________ Filter to remove any ________ that forms Step 2: Add ___________ to precipitate ___________ Filter to remove any ________ that forms Step 3: Add ___________ to precipitate ___________ Filter to remove any ________ that forms Step 4: Add ___________ to precipitate ___________ Filter to remove any ________ that forms

30. Work on Questions… 26, 30, 32, 35, 37.