the decrease in concentration of a reactant

increase in concentration of a product in a unit of time.

units

a description of the path that a reaction takes.

A reaction was completed through several elementary reactions.

A reaction can complete directly by only one step or reactants can convert into products.

⑴ reacting molecules must come so close that they collide.

⑵ not every collision between molecules creates products, only few collisions between reactant molecules will react.

⑶ enough energy; proper orientation

•Activation molecules

activation energy (Ea):

reactants pass through high-energy transition states before forming products, they are associated in an unstable entity called an activated complex, then change into products.

① when [A]=[B]=1mol·L-1 , v=k

② the greater the k , the faster the rate

③ m and n must be determined experimentally, in general, m and n are not equal to the stoichiometric coefficients a and b

m is the order of the reaction with respect to A

n is the order of the reaction with respect to B.

The overall order of the reaction is the sum of m and n

The initial concentrations of A and B are the same

 The features of catalysts

three types: