1. Period 3 Advanced Chemistry
Bell Task-Determine the type of intermolecular force present in each of the following. check quizzes with each other!
A. CH3OH
B. CH3CH2CH3
Agenda:
Bell Task and review
Weekly agenda
Review quizzes from last week
Phase Diagrams

2. Period 3 Advanced Chemistry
Bell Task- Identify the following statements as endothermic or exothermic reactions and identify the sign of delta H and delta S.
1. Carbon Dioxide subliming
2. N2 gas condensing
3. Ethanol evaporating
4. Sodium Thiosulfate liquifying
5. Water crystallizing

3. Examples of Phase Changes
Phase Change (State Change): A change in physical form but not the chemical identity of a substance.
Fusion (melting):
Vaporization :
Sublimation:
solid to liquid
liquid to gas
solid to gas
Freezing:
Condensation:
Deposition:
liquid to solid
gas to liquid
gas to solid

5. When randomness increases, S with + (endothermic)
H = Enthalpy which is associated with heat flow and making or breaking
the attractiions that hold liquids and solids together
(+) = endothermic reaction
(-) = exothermic reaction
S = Entropy and is the measure of disorder
When randomness increases, S with + (endothermic)
When randomness decreases, S with - (exothermic)
G= Gibbs Free Energy and is thought as the maximum amount of work obtainable from a reaction and is an indicator of spontaneity!
This formula helps determine the temperature at which a change occurs!
when delta G = 0 helps calculate the temperature when two phases are in equilibrium!

6. Question:
In terms of intermolecular forces, why are Hf and Hv so different?
Hf-
Hv-
Values

7. Prove that water melts at 273K using Free Energy Change calculation

8. Check HW problem 10.8
Try problem and 10.58

10. For phase changes that are endothermic delta H and delta S are +
For phase changes that are exothermic delta H and delta S are -

17. Phase Changes

18. Heat (Enthalpy) of Fusion (DHfusion ): The amount of energy required to overcome enough intermolecular forces to convert a solid to a liquid.
Heat (Enthalpy) of Vaporization (DHvap): The amount of energy required to overcome enough intermolecular forces to convert a liquid to a gas.

19. Phase Changes

21. Enthalpy