Unit 2 Topic 4 ✓ Flashcards
Physical Chemistry: Reaction Kinetics
What is Reaction Kinetics?
Reaction kinetics is the study of reaction rates. It allows an understanding of how reactions work
What is a Reaction Mechanism?
A reaction mechanism is the series of steps that a reaction takes. It cannot be deduced using the balanced chemical equation, it can only be worked out by experiment
What is an Elementary reaction?
An elementary reaction is a reaction that occurs in a single step
What is a Composite reaction?
A composite reaction is a reaction that occurs in several steps
NOTE: A balanced equation of a composite reaction only shows the sum of all the steps
What is a Zero order reaction?
A zero order reaction is a reaction where the rate is not dependant on the concentration of the reactant
NOTE: Revise zero order rate graphs
What is a First order reaction?
A first order reaction is a reaction where the rate doubles when the concentration of the reactant doubles
NOTE: Revise first order rate graphs
What is a Second order reaction?
A second order reaction is a reaction where the rate quadruples (x4) when the concentration of a reactant is doubled
NOTE: Revise second order rate graphs
What is Reaction order?
Reaction order is the relationship between reactant concentration and the rate of the reaction. It is the number of each species reacting in the rate determining step.
NOTE: It does not involve the number of moles of reactants
What is the Rate constant? (k)
The rate constant is the proportionality constant. It can relate the rate of a chemical reaction to the concentration of reactant or products of those reactants
What is the Half-life of a reaction?
The half-life of a reaction is the time taken for the concentration of the reactant to decrease to 1/2 its initial value
What is the Rate determining step (RDS) of a composite reaction?
The rate determining step is the slowest step in a multi-step mecahnism (composite). This step controls the overall rate of the reaction
