The area of chemistry concerned with reaction rates and the sequence of steps by which reactions occur
Either the increase in the concentration of a product per unit time or the decrease in the concentration of a reactant per unit time
Rate = _______________________
An equation that shows the dependence of the reaction rate on the concentration of each reactant
Elementary Reaction vs overall reation
-A single step in a reaction mechanism, describes an individual molecular event.
-describes the reaction stoichiometry and is a summation of the elementary reactions.
A classification of an elementary reaction based on the number of molecules (or atoms) on the reactant side of the chemical equation.
reaction rate laws and molecularity
The rate law for an elementary reaction follows directly from its molecularity because an elementary reaction is an individual molecular event
The slowest step in a reaction mechanism. It acts as a bottleneck and limits the rate at which reactants can be converted to products
The configuration of atoms at the maximum in the potential energy profile. This is also called the activated complex.
As the average kinetic energy increases, the average molecular speed increases, and thus the collision rate increases.
Activation Energy (Ea)
The minimum energy needed for reaction. As the temperature increases, the fraction of collisions with sufficient energy to react increases.
a different form of collision theory equation, where A(=pZ) is the frequency factor
A substance that increases the rate of a reaction without itself being consumed in the reaction. A catalyst is used in one step and regenerated in a later step.
Since the catalyst is involved in the rate-determining step, it often appears in the rate law.
Homogeneous vs Heterogeneous Catalysts
A catalyst that exists in the same phase as the reactants.(iodide in decomposition of peroxide)
A catalyst that exists in a different phase from that of the reactants.(commercial use eg. gas exhausted from automobile engines)