Collisions must have enough energy to produce the reaction (must equal or exceed the activation energy).
Reactants must have proper orientation to allow the formation of new bonds.
The minimum energy required to transform reactants into the activated complex
(The minimum energy required to produce an effective collision)
Flame, spark, high temperature, radiation are all sources of activation energy
Processes in which energy is released as it proceeds, and surroundings become warmer
Reactants Products + energy
Processes in which energy is absorbed as it proceeds, and surroundings become colder
Reactants + energy Products
2NO2(g) 2NO(g) + O2(g)
2. Can measure
1. Can measure
3. Are proportional
The reaction mechanism is the series of steps by which a chemical reaction occurs.
A chemical equation does not tell us how reactants become products; it is a summary of the overall process.
The sign has represents the reaction mechanism, but gives no indication of the steps in the mechanism
In a multi-step reaction, the slowest step is the rate-determining step. It therefore determines the rate of reaction.
Increasing temperature always increases the rate of a reaction.
Increasing surface area increases the rate of a reaction
Increasing concentration USUALLY increases the rate of a reaction
Presence of Catalysts