Kinetics Flashcards
Activation energy
The minimum energy required for a chemical reaction to take place
Rate constant
The rate constant, K, is the constant in the rate equation. The units of K vary according to the order of the reaction
Order of reaction
The order of reaction with respect to a reactant is the power to which its concentration is raised in the rate equation. The overall order of the reaction is the sum of the orders with respect to individual reactants
Catalyst
Increases the rate of chemical reaction without itself being used up in the reaction; a catalyst acts by allowing the reaction to proceed by an alternative pathway of lower activation energy.
Collision theory
a reaction can occur only when two particles collide in the correct orientation and with E > Ea
Half-life
The time it takes for the number of radioactive nuclei present in a sample at any given time to fall to half its value
Maxwell-Boltzmann distribution
A graph showing the distribution of molecular kinetic energies in a sample of gas at a particular temperature
molecularity
the number of molecules that react in a particular step in a chemical reaction
Order of a reaction
The power of the concentration of a particular reactant in the experimentally determined rate reaction.
Overall order of reaction
sum of the powers of the concentration terms in the experimentally determined rate equation
Rate determining step
The slowest step in a reaction mechanism
Rate constant (K)
constant of proportionality relating the concentrations in the experimentally determined rate expression to the rate of a chemical reaction; the rate constant is only a constant for a particular reaction at a particular temperature
Rate expression
A determined equation that relates the rate of reaction to the concentrations of substances in the reaction mixture
rate of reaction
the speed at which reactants are used up or products are formed; more precisely the change in a concentration of reactants or products per unit time
Transition state (activated complex)
the highest energy species on the reaction pathway between reactants and products; the highest point on potential energy profile
