1. Review:

2. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute + H H - + - + O + - + - - - + - +

3. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute + H H - + - + O + - + - - - + - +

4. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute + H H - + - + O + - + - - - + - +

5. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute + H H - + - + O + - + - - - + - +

6. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute - + - + + H H O + - + - - - + - +

7. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute - + - + + + - + - H H O - + - + -

8. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute - + - + + H H - + - + O - + - + -

9. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute - + - + + H H - O + - + - - + - +

10. - - - - - - So What does Dissolving Look Like? The simple version … O
Chunks of solute + H H - - + - + O + - + - - + - +

11. - - - - - - So What does Dissolving Look Like? The simple version … O+
Chunks of solute H H - O - + - + - + - + - + - +

12. really ^
So What does Dissolving Look Like?
Differences between ionic solutions and molecular solutions …

14. really ^
So What does Dissolving Look Like?
Differences between ionic solutions and molecular solutions …
1. Ionic solutions – ions separate
2. Molecular solutions – molecules separate from each other, but stay intact

15. really ^
So What does Dissolving Look Like?
There are actually several different bond making, and bond breaking steps going on as a substance dissolves.

16. - + - + + - + - - + - +

17. + - + - + - + - - + - +

18. + - + - + - + - - + - +

19. - + - + + - + - - + - +

20. - + - + + + - + - - + -

21. So What does Dissolving Look Like?
really ^
So What does Dissolving Look Like?
There are actually several different bond making, and bond breaking steps going on as a substance dissolves.
The solute-solvent attractions must be stronger than the solute-solute and solvent-solvent attractions
Bonds Broken: 1.
Solute-solute bonds 2.
Solvent-solvent bonds
Bonds Formed: 1.
Solute-solvent bonds

22. So What does Dissolving Look Like?
really ^
So What does Dissolving Look Like?
Yes
Ionic bonds
H-bonds
Ion-dipole
Ion-dipole
H-bonds between ethanol
H-bonds between water
H-bonds between ethanol - water
H-bonds between ethanol - water
Yes
LD forces between I2
LD forces between CCl4
LD forces between I2 and CCl4
LD forces between I2 and CCl4
Yes
LD forces between O2
H-bonds between water
LD force between O2 and H2O
H-bonds between water NO

23. So What does Dissolving Look Like? Energy Factors:
really ^
So What does Dissolving Look Like?
Energy Factors:
What is the net energy change?
Requires 10 kJ/mol
Requires 15 kJ/mol
Releases 20 kJ/mol
Bonds Broken:
Requires Energy (endothermic) 1.
Forces within the solute 2.
Forces within the solvent
Bonds Formed:
Releases Energy (exothermic) 1.
Forces between solute and solvent

24. So What does Dissolving Look Like? Energy Factors:
really ^
So What does Dissolving Look Like?
Energy Factors:
The net energy lost or gained as heat when a substance is dissolved is called the enthalpy of solution
∆Hsolution =
+ value  endo.
- value  exo.
units are kJ/mol

25. Sample AP Model Drawing Question

27. Try the sample AP Model Drawing question on the back AND #1 and #2 in the Solubility Practice Questions