1. Unit 9
Solution Chemistry

2. H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl
Pour liquid between 2 beakers along with this slide.
Is this evaporating?
What does evaporating look like, in terms of these molecules?
Is this evaporating very fast?
Why? H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl

3. H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cld+ d- H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl H Cl

4. d+ d- H Cl H Cl H H Cl Cl H Cl H Cl H Cl H H Cl

5. d+ d- H Cl

6. d+ d- H Cl

7. Intermolecular Forces
Attraction forces between molecules

8. Intramolecular Force Intermolecular Force
Ionic bond
Covalent bond
Polar covalent bond
Hold together ATOMS
Breaking = chemical reaction
Dipole-dipole
London forces
Hydrogen bond
Hold together MOLECULES
Breaking = phase change, dissolving

9. A. Dipole-dipole
molecule must be ______________ (molecules with polar covalent bonds are not necessarily polar)
d- side of the molecule is attracted to the d+ side
can be intramolecular as well
polar
Non-polar
Polar

10. Practice: Which of the following molecules are polar?
CH4
H2O
NH3 

11. Br
Show a bottle of liquid Br2

12. Dipole moment - - - d- d+ - - - - - -
London force

13. Hmmmm…. Which of the following molecules can have London forces? MgO
H2S
CH4
C6H14
All of the above

14. Consider This: Why is chlorine a gas at room temperature, but bromine a liquid?

15. Sample Question
Which of the following molecules has the strongest (or biggest) London force?
MgO
H2S
CH4
C6H14
All of the above have the same amount

16. B. London Forces a momentary dipole temporary dipole
molecule is non polar or polar
weak and short-lived attractive force caused by
_______________________
recall e- distribution is described as a probability
at any given point in time, the distribution might be uneven, creating a ____________________on the molecule
Increases with increasing #e- and size of the molecule
a momentary dipole
temporary dipole

17. C. Hydrogen Bonds
molecule contains an H atom bonded to a very electronegative atom (_____, _____, ____)
the H atom of one molecule is attracted to the F, O, or N on another molecule F O N

18. C. Hydrogen Bonds
molecule contains an H atom bonded to a very electronegative atom (_____, _____, ____)
the H atom of one molecule is attracted to the F, O, or N on another molecule
the strongest of the intermolecular forces
H has no e- to get in the way of its attraction to F, O, or N F O N

19. H – F
H – F
What would be something that would get in the way of intermolecular forces?

20. H – F
H – F

21. Example: Which of the following molecules can hydrogen bond?
HCN H2O H2S HF

22. Arrange water molecules to reflect the structure of ice.

26. Melting Point Boiling Point

27. d+ d- d- d+ d+ d+ d+ d+ d+
nail polish remover
rubbing alcohol
hexane d+ d+ d+ d+ d+ d+ d+ d- d- d- d- d- d- d+ d+ d+ d+ d+ d+ d+

28. broken more stronger higher larger mass higher
Intermolecular bonds are responsible for how readily covalent substances undergo physical changes
Intermolecular forces must be _____________
The ____________ intermolecular forces present, and the ______________ that they are, the ______________ the melting and boiling points
The _______________ the molecule and the higher the ________________, the _____________ the boiling point.
broken
more
stronger
higher
larger
mass
higher

29. Example: Among H2O, CO2, and H2S, explain why H2O has the highest boiling point at 100C, followed by H2S at C, then CO2 at-78.44C