1. Unit Nine Review

2. IMF Intermolecular forces The three states of matter depend on
Attractive forces between molecules
The three states of matter depend on
Strength of IMF relative to the amount of thermal energy
Weaker IMF
Gas
Stronger IMF
Solid or liquid

3. IMF Surface tension Viscosity Volatile Dynamic equilibrium
Tendency of liquids to minimize surface area
Stronger IMF, greater surface tension
Viscosity
Resistance of a liquid to flow
Stronger IMF, greater viscosity
Volatile
Easily evaporates
Dynamic equilibrium
Rate of condensation = rate of evaporation
Vapors condensing = liquid evaporating
Vapor pressure
Pressure exerted by a liquids vapor molecules

4. Phase Change Boiling occurs throughout the liquid
Evaporation occurs only at the surface
Rate of Vaporization increases
Increase surface area
Increase temperature
Decrease strength of IMF
Vapor pressure increases
Make a liquid boil
Decrease atm pressure (lowers bp)
Make a gas condense
Decrease temperature
Increase atm pressure
Melting
Solid to liquid
Freezing
Liquid to solid
Boiling
Liquid to gas
Condensation
Gas to liquid
Sublimation
Solid to gas
Deposition
Gas to solid

5. Calculations Be able to use the
Heat of vaporization (boiling/condensing plateau)
Heat of fusion (melting/freezing plateau)
Specific Heat (slope)
q=mCΔT
equations to calculate the energy required

7. Types of IMF Dispersion Dipole – Dipole Hydrogen Bonds
Temporary uneven distribution of electrons
Molar mass
Symmetry
Surface area
Dipole – Dipole
Permanent uneven distribution of electrons
Hydrogen Bonds
H bonded to N, O, or F

8. Solids Molecular Covalent Metallic Ionic Neutral corners
Low melting points
NM & NM
M & ML or ML & NM
Covalent
High melting points
ML & ML
Metallic
Positive ions (cations)
M & M
Ionic
Positive and negative ions (cations and anions)
M & NM

9. Water
Why is water unique?
Hydrate calculations (Worksheet 4)