Introduction to Reaction Kinetics
Terms
Activation Energy
-
The difference in energy between the reactants and the transition state
that is the energy barrier
the reactants must overcome to achieve a chemical reaction.
Catalyst
-
A substance that lowers the activation energy for a chemical reaction
without being chemically
altered by the reaction.
Elementary Step
-
A reaction that represents a single collision or intramolecular step in a
reaction mechanism.
Integrated Rate Law
-
The integral (a calculus operation) of the rate law, this form of the
rate law shows the
dependence of the concentration of reactants on time of reaction.
Intermediate
-
A species that is both produced and consumed in a chemical reaction. An
intermediate does not appear in
the overall reaction expression but is proposed to be produced in one
elementary
step and consumed in
another.
Kinetics
-
The study of the rates and mechanisms of chemical reactions.
Mechanism
-
The series of elementary steps that combine to produce the path molecules
take from reactant(s) to
product(s) in a chemical reaction.
Method of Initial Rates
-
A series of experiments wherein the concentration of one reagent at a time
is varied and the initial rate
(rate at time zero) of the reaction is measured. By comparing the change
in concentration to the
change in rate, it is possible to determine the order of each reagent in a
reaction.
Order
-
In the rate law of a reaction, the power to which the concentration of a
reagent is raised. Or, the sum of the powers on the concentration terms in the
rate law.
Rate
-
The speed of a reaction measured in amount of reagent consumed or product
produced per unit time.
Rate Law
-
An expression of the dependence of the rate of a reaction on the
concentrations of reactants.
Reaction Coordinate Diagram
-
A plot of free energy versus the reaction coordinate for a reaction that
provides a pictorial
representation of the lowest energy path from reactants to products.
Transition State
-
The species with the highest energy between reactant and product on a
reaction coordinate
diagram, it is a short-lived species that represents a combination of
product-like and reactant-like
properties.
