1. Chemistry Chapter 16: Reaction Rates
The reaction rate, of a reaction, is the Δ of reactants or products per second.
The Δ of reactants= Δ of products, much like the Δ of amount of sand in the top of an hour-glass changes = to the Δ of change in the bottom.
Reaction Rate = Δ of reactants
second
Units of reaction rate are… M/s=(mol/L)*1/s=mol/L*s

2. Collision Theory
Collision Theory states that there must be collisions to cause reactions…the more number and greater force of collisions, the more reactions.
Once reacting particles collide, they form the activated complex, which is a ‘morph’ of the reactant and product.
Reactions require activation energy in order for a reaction to start.

3. Energy Diagrams An energy diagram graphs energy (y) v time (x)
An activation energy (ΔE) is required to start the reation.
Multiple humps indicate multiple steps called elementary reactions.
A transition state or activated complex exists during activation.
The taller the front slope, the slower the reaction, the shorter, the faster.
Intermediates are products formed by elementary reactions, that may or may not stay in tact for the overall reactiion…they may be used up by the next step.

4. Spontaneity and Reaction Rate
ΔG is Gibb’s free energy.
- ΔG means a spontaneous reaction, + ΔG means non-spontaneous.

5. 16-2 Factors Affecting Reaction Rate
The nature of reactants.
Concentration
Larger surface area/smaller particle size.
Temperature.
Catalysts.
Inhibitors.

6. Catalysts
Catalysts work by lowering the required activation energy.

7. Types of Catalysts
Homogeneous catalysts are the same physical state as the reactants.
Heterogeneous catalysts are a different physical state as the reactants.