1. Jenni and Aaron’s…

2. Solubility Solubility is the quantity of a particular substance that can dissolve in a particular solvent (yielding a saturated solution) A salt can be considered soluble if >1g of salt can be dissolved in 100mL Soluble salts are assumed to dissociate completely in aqueous solution

3. Henry’s Law: Effect of Pressure on Solubility The solubility of a gas in a liquid is directly proportional to the gas pressure S g = k H P g S g = gas solubility (M) k H = Henry’s law constant (M/mmHg) P g = partial pressure of the gaseous solute (mmHg)

4. Le Chatelier’s Principle: Effect of Temperature on Solubility The solubility of gas in a liquid is inversely proportional to the gas temperature –Usually, the gas solubility rxn is exothermic so, Gas + liquid solvent   saturated solution + heat energy A change in any of the factors determining an equilibrium causes the system to shift –In this case, the reaction shifts left

5. Solubility Product Constant (K sp ) K sp is a measure of the extent of a salt’s dissociation in solution The greater the value of the solubility product of a salt, the more soluble the salt is For the Reaction: A a B b (s)  a A b+ (aq) +b B a+ (aq) –The solubility expression is: K sp = [A b+ ] a [B a- ] b

6. Reaction Quotient (Q) For the Reaction: A a B b (s)  a A b+ (aq) +b B a+ (aq) –The solubility expression is: Q = [A b+ ] a [B a- ] b What’s the difference between Q and K sp ? –Q is used for a chemical reaction which is not necessarily at equilibrium

7. Q vs. K sp If Q = K sp, the system is at equilibrium and is saturated (no precipitation) If Q < K sp, the system is not at eq. and is not saturated (precipitation) If Q > K sp, the system is not at eq. and is supersaturated (precipitation)

8. The Common Ion Effect Using: K sp = [Ag + ][Cl - ] = 1.6x10 -10 We know: (x)(x) = 1.6x10 -10 And:x = [Ag + ] = [Cl - ] = 1.3 x 10 -5 So what if we added 0.10 mol of NaCl to 1 liter of this AgCl solution? Hmmm…

9. Common Ion Effect Cont’d The NaCl dissociates completely, so that’s the same thing as adding 1 mol Na + ions and 1 mol Cl - ions to the solution We must take into account the new Cl - ions because of this so-called… “common ion effect” Let’s take a look at the expression now [Ag + ][Cl - ] = 1.6x10 -10 [Ag + ](0.10M) = 1.6x10 -10 [Ag + ] = 1.6x10 -9

10. A complex ion is formed by combination of simpler ions or molecules –Example: Co 2+ combines with 6 H 2 O to form the complex ion Co(H 2 O) 6 2+.

11. Complex Ions Cont’d Hmmm….

12. (THE END)