1. Kinetics Lesson 1

2. Kinetics & Equilibrium
Kinetics - deals with the rate of chemical reactions and the mechanisms by which chemical reactions occur.
Reaction Rate - a change in concentration per unit of time.
Δ Concentration
second
Reactions of chlorine 5:33

3. Reaction Mechanism - a sequence of stepwise reactions by which the overall change occurs.
2NO(g) + F2(g)  2NOF(g)
Step 1: NO(g) + F2(g)  NOF2(g)
Step 2: NOF2(g) + NO(g)  2NOF(g)
NO(g) + F2(g) + NOF2(g) + NO(g)  NOF2(g) + 2NOF(g)
2 NO(g) + F2(g)  2NOF(g)

4. Kinetics & Equilibrium
If molecules were people animation 04:45
Collision Theory
- states that substances must collide in order to react.
effective collision - collision leads to formation of products.
ineffective collision - collision does not lead to the formation of products.
Orientation in a Chemical Reaction

5. Activated complex - a short lived transitional structure that is
neither reactant nor product
Activation Energy Ea - minimum energy needed to initiate a reaction
Activation Energy narrated animation 01:16
Activation Energy Diagrams
Heat of a Reaction (Enthalpy)
- the heat energy released or absorbed in the reaction.
ΔH = Hproducts - Hreactants
Activation Energy narrated – Bozman Science 4:51

6. Kinetics & Equilibrium
Endothermic reaction - energy is absorbed
ΔH = + positive
Exothermic reaction - energy is released
Δ H = - negative

7. Factors Affecting Rate of Reaction
Nature of Reactants
- bonding (how strong are they bonded – ionic, covalent)
- less rearrangement of atoms needed to form effective activated complex the faster the reaction
(symmetry – polar, nonpolar)

8. Factors Affecting Rate of Reaction
Nature of Reactants
- bonding (how strong are they bonded – ionic, covalent)
- less rearrangement of atoms needed to form effective activated complex the faster the reaction
(symmetry – polar, nonpolar)
- physical state (gases will react faster than solids)
increased motion = increased collisions
basically anything that increases the # of collisions
will make the reaction happen faster

9. Factors Affecting Rate of Reaction
Concentration
- increase concentrations => increase the rate of reaction
Concentration Rxn rate
- increase concentrations => increase the frequency of collisions
Concentration # collisions

10. Factors Affecting Rate of Reaction
3) Temperature
- increase temperature => increase the rate of reaction
Temperature Rxn rate
- increase temperature => increase the kinetic energy KE
=> increase frequency of collisions
Temperature KE
# collisions

11. Factors Affecting Rate of Reaction
4) Surface Area
- increase surface area => increase the frequency of collisions
Surface Area # Collisions

12. Factors Affecting Rate of Reaction
4) Surface Area
- increase surface area => increase the frequency of collisions
Surface Area # Collisions

13. Factors Affecting Rate of Reaction
4) Surface Area
- increase surface area => increase the frequency of collisions
Surface Area # Collisions

14. Factors Affecting Rate of Reaction
5) Catalysts
- changes the mechanism to one that involves
less activation energy (lowers the activation energy)
- increases the rate of the reaction without itself being used up in the reaction – just speeds up the reaction
*Does not change the ∆H or the amount of product that is produced,
it just makes it happen faster.
A + B → AB
catalyst
The 10 Most AMAZING Chemical Reactions (with Reactions) 13:09
Big Bang Theory Sheldon’s Revenge 02:48