how does the rate of a chemical reaction relate to concentrations of the reactants?
through the rate equation = k[A]^m[B]^n
what is the 'order of reaction'?
the power to which the reactant concentration is raised in the rate equation.
how can this be determined?
experimentally, either by using the shapes of the initial rate-concentration graphs produced OR by mathematical analysis of initial rate and concentration data in a table.
zero order.
if a reaction is zero order with respect to a reactant, then the rate of reaction is unaffected by any changes in concentration of that reactant.
typical shape of the graph made when a reaction is zero order with respect to that reactant:
first order.
rate is directly proportional to the concentration of that reactant.
any increase in concentration of that reactant results in the same increase as rate.
eg: if concentration of the reactant doubles then rate also doubles.
second order.
any change made to the concentration of that reactant results in the rate being changed by the same factor squared.
eg: if concentration of the reactant doubles then rate increases by a factor of 2^2 so x 4.
eg: if concentration of the reactant triples then rate increases by a factor of 3^2 so x 9.
how can we obtain a second order reaction?
you have to plot a graph of initial rate against concentration squared.
