Collision Theory

Collision Theory

Reaction rates are not constant, dependent on conditions which reactions take place.

Rule #1

For a reaction to take place, reactants must collide.

Rule #2

When molecules collide, they must have be in optimal orientation.

Rule #3

When molecules collide, they must have a certain minimum amount of energy in order for the reaction to occur.

Activation Energy (Ea)

Minimum amount of energy that must be attained for reaction to take place.

Exothermic

-deltaH

Leave heat

High reactant energy, low product energy

Endothermic

+deltaH

Absorbs heat

Low reactant energy, high product energy

Reaction Progress

UP Ea = DOWN speed

Concentration Vs Rate

UP Concentration = UP Reaction Rate

Surface Area Vs Rate

UP Surface Area = UP Reaction Rate

Temperature Vs Rate

More heat energy (rapid molecules and more to overcome Ea)

UP Temperature = UP Reaction Rate

Catalysts Vs Rate

UP Catalysts = DOWN Ea = UP Reaction Rate

Incomplete Combustion

Not enough O2 to create reaction with every molecule

Ex,,,,

Combustion converter & Biological