1. Second Semester Review

2. Heating Curve

3. Heating Curve q (heat energy) = mcT
q=mHv
Gas
Liquid
q=mHf
solid
q (heat energy) = mcT
Where is potential energy increasing?
Where is kinetic energy increasing?

4. Phase Diagram

5. Vapor Pressure Diagram
Intersection of curved lines and standard pressure (bold line at 1 atm) is the normal boiling point

6. Intermolecular Forces
Inter- means “between” or “among”
Intermolecular forces hold two molecules together
Ex: Water in a drop, carbon and cellulose (aka. pencil lead & paper)
Weak intermolecular forces
Low boiling points
Most likely in gaseous state
Strong intermolecular forces
High boiling points
Most likely in solid state

7. Intermolecular Forces

8. Boiling Point Boiling occurs throughout the liquid
Boiling point occurs when Vapor Pressure=Atmospheric Pressure
Higher altitudes have lower atmospheric pressure. Would the boiling point increase or decrease?
Would it take a longer or shorter time to cook food?

9. Gas Laws Combined Gas Law
If you do not have a change in one of the variables replace it with a one or omit it!
Temperature must be in Kelvin! (TC = TK)
Only need ONE FORMULA!!!!!!

10. Gas Stoichiometry
Gas stoichiometry can be done using the coefficients of the balanced chemical equation and ratios

11. Solutions & Solubility
Soluble (miscible): like dissolves like
Polar or Ionic solutes dissolve in polar solvents
Areas of charge are attracted to one another
Ex: water, alcohol, sugar, salt
Non-polar solutes dissolve in non-polar solvents
No charges so there is no attraction
Ex: oils, gasoline, diatomic molecules (H O F Br I N Cl)
Insoluble (immiscible): do not dissolve in each other
Polar and non-polar
Ex: oil and water

12. Solubility Curve
Above the curve would be supersaturated if completely dissolved (in solution)
The curve itself is at saturation
Below the curve indicates unsaturated solutions
Negative (downward) slope indicates a gas

13. Concentration
Molarity (M): # mol solute dissolved in 1 L of solution

14. Heat Energy (Enthalpy)
Heat, which is represented by the symbol q, is energy that is in the process of flowing from a warmer object to a cooler object.
When the warmer object loses heat, its temperature decreases.
When the cooler object absorbs heat, its temperature rises.
H : Tells us if a reaction is endothermic or exothermic (measure of change in energy)

15. Exothermic Reaction
Energy flows from system to surroundings

16. Endothermic Reaction
Energy Flows from Surroundings to System

17. Factors that Effect Reaction Rate
Concentration of Reactants
The more particles, the more collisions
As concentration increases, rate increases

18. Factors that Effect Reaction Rate
Temperature of Reactants
As temperature increases, particles move faster; there are more high-energy collisions

19. Factors that Effect Reaction Rate
Particle Size (surface area)
For solids, breaking up big pieces increases surface area, increasing rate by having more places for the molecules to interact

20. Factors that Effect Reaction Rate
Pressure – Gases only!
As pressure increases the concentration increases, so you will have more collisions

21. Factors that Effect Reaction Rate
Catalysts – compounds added to speed up reaction but not used in the reaction.
Lowers activation energy but does not change ΔH
Examples: enzymes in your body, catalytic converters
(Pt, Rh, or Pd plates that convert NO → N2 + O2 and CO → CO2)

22. Factors that Effect Reaction Rate
Inhibitors
Compounds added to a reaction that slow it down
Examples: Lead in diesel, preservatives in food.