Download chapter 13 solubility.notebook

chapter 13 solubility.notebook
January 13, 2016
1. Learn how to manage big amounts of information.
2. Set up a review plan to follow each day. Make it small (15 min) because you are more likely to stick with that.
3. Sign up for the AP Question of the Day
CHAPTER 13: PROPERTIES OF SOLUTIONS
13.1 Types of solutions: IMFs and Solubility
4. Buy an AP review book.
13.2 IMFs and Biological Macromolecules (did it already but you should read it anyway)
5. Make a list of concepts that are hard for you and start reviewing those.
13.3 Why stuff will dissolve: the solution process
6. READ YOUR BOOK!
13.4 Solubility as and Equilibrium Process
7. Watch at least one video per chapter.
8. We can start afternoon review sessions NOW! Just let me know which day/week works for you.
9. Keep up with new material. It's about to get intense!
10. Start memorizing stuff.
11. Tell me what you need me to do.
Jan 13­4:10 PM
* Solutions are homogeneous mixtures of solute (ions, molecules, atoms) and solvent.
Jan 13­4:14 PM
Intermolecular forces in solution:
H-bonds:
alcohols, amines and amino acids
* Miscible means "mixable"
* The solvent is the portion of the solution that's most abudant.
* Solubility (S): the maximum amount of solute that dissolves in a fixed quantity of a given solvent; varies with temperature rely on polarizability
Jan 13­4:17 PM
Contribute to solubility of all solutes but is principal IMF for nonpolar things (gasoline)
Jan 13­10:16 AM
Hydration shells: cluster of water molecules surrounding ions
Usually 4-6 waters/ion (bigger ions get more waters)
Jan 13­10:16 AM
Jan 13­10:18 AM
1
chapter 13 solubility.notebook
January 13, 2016
Alcohols have DUAL POLARITY:
Forces within solute and solvent replace each other and a solution forms.
polar hydroxyl group (-OH) and nonpolar hydrocarbon group (R)
-OH group: H-bond with water
R group: weak dipole induced dipole with water
Jan 13­10:19 AM
Jan 13­10:19 AM
Gas - Liquid Solutions
Things like O 2
* weak IMFs = low BP = gases The lower the boiling point of a gas, the lower the solubility
Things like CO 2 can dissolve AND react, making its solubility seem larger than expected:
+
-
CO 2 (g) + H 2O (g) --> H (aq) + HCO 3 (aq) Jan 13­4:34 PM
ALL gases can dissolve within each other.
Jan 13­4:36 PM
Substitutional and Interstitial Alloys = SOLID SOLUTIONS
Some gases can dissolve in solids (hydrogen in between Pd atoms)
Oxygen can dissolve into copper, form Cu 2O, and reduce conductivity
Jan 13­4:43 PM
Jan 13­4:45 PM
2
chapter 13 solubility.notebook
January 13, 2016
Thermochemical Solution Cycle:
The Solution Process
H
soln
Heat of solution
If is really, really, H
really endo, solute may not even dissolve.
soln
Jan 13­10:28 AM
Jan 13­4:49 PM
Lattice Energy enthalpy change when 1 mole of an ionic solid is separated into gaseous ions
(g)
* the harder they are to separate, the bigger the lattice energy
(g)
Jan 13­10:29 AM
Jan 13­4:54 PM
Heat of Hydration: enthalpy changes for separating water molecules ( H solvent ) and mixing with solute ( H mix )
Super important when dissolving ionic solids
Energy of breaking H-bonds << Energy released when mixed
Heat of Hydration is always EXOTHERMIC
+
-
H 20
+
-
Na (g) + Cl (g) --> Na (aq) + Cl (aq)
Jan 13­4:54 PM
Jan 13­10:30 AM
3
chapter 13 solubility.notebook
January 13, 2016
Charge Density: ratio of an ions charge to its volume
THE HIGHER THE CHARGE DENSITY, THE MORE NEGATIVE HEAT OF HYDRATION.
+2
vs
+1
+1
vs
+1
smaller ion attracts water
more strongly
higher charge density, greater attraction to water
Jan 13­5:15 PM
Jan 13­5:17 PM
Jan 13­5:21 PM
Jan 13­5:12 PM
The heat of solution is not the only thing that determines if a solute dissolves.
ENTROPY
Jan 13­5:12 PM
Jan 13­5:34 PM
4
chapter 13 solubility.notebook
January 13, 2016
Entropy (S): the number of ways a system can disperse its energy (related freedom of movement)
Jan 13­5:31 PM
Usually systems tend towards
Jan 13­5:30 PM
Solubility and Equilibrium
LOW ENTHALPY and HIGH ENTROPY
Jan 13­5:35 PM
Jan 13­5:27 PM
Jan 13­10:32 AM
Jan 13­10:33 AM
5
chapter 13 solubility.notebook
Saturated
January 13, 2016
Solubility of Gases and Temperature
Unsaturated
Supersaturated
Jan 13­10:34 AM
Jan 13­5:42 PM
6