collision theory

Collision Theory

For a reaction to occur reactant molecules must collide with energy greater than some minimum required value and with the proper orientation

Activation Energy

The minimum energy required for two molecules to react

Transition State Theory

•  unstable grouping of atoms is formed in a collision with sufficient E_a.  This molecule is called the Activated Complex, so they’re just colliding together rn

• activated complex will yield either the original reactants or new products. New products could be an intermediate before final product is made

Factors that Affect Rates

1. Nature of reactants

2. Temperature

3. Concentration

4. Surface area

5. Catalysts

Rate = Z · f · p define variables

• Z → Frequency of collisions

• f → Energy necessary for effective collision

• p → fraction of collisions with correct orientation

Maxwell-Boltzmann graph

• snapshot of a moment in time

• you can measure how fast each particle is moving at that moment and at the current temperature

• more energy (temp) = more collisions

Catalysts

speed up the rate of a reaction by reducing the activation energy (E_a) necessary to form one of the transition state molecules.

heterogeneous catalysts

catalyst in a different phase

homogeneous catalyst

catalyst in the same phase as the substances reacting