Chapter 13: Chemical Kinetics Flashcards
Activated Complex
the species temporarily formed by the reactant molecules as a result of the collision before they form the product
Activation Energy (Ea)
the minimum amount of energy required to initiate a chemical reaction
Bimolecular Reaction
an elementary step that involves two molecules
Catalyst
a substance that increases the rate of a chemical reaction without itself being consumed
Chemical Kinetics
the area of chemistry concerned with the speeds, or rates at which chemical reactions occur
Elementary Step
A series of simple reactions that represent the progress of the overall reaction at the molecular level
Enzyme
a biological catalyst
First-order Reaction
a reaction whose rate depends on reactant concentration raised to the first power
Half-life (t 1/2)
the time required for the concentration of a reactant to decrease to half of its initial concentration
Intermediate
a species that appears in the mechanism of the reaction (that is, the elementary steps) but not in the overall balanced equation
Molecularity of a reaction
the number of molecules reacting in an elementary step
Rate constant (k)
constant of proportionality between the reaction rate and the concentrations of reactants
Rate-determining step
the slowest step in the sequence of steps leading to the formation of products
Rate Law
an expression relating to the rate of a reaction to the rate constant and the concentrations of the reactants
Reaction mechanism
the sequence of elementary steps that leads to product formation
Reaction order
the sum of the powers to which all reactant concentrations appearing in the rate law are raised
Reaction rate
the change in the concentration of reacting or product with time
Second-order Reaction
a reaction whose rate depends on reactant concentration raised to the second power or on the concentrations of two different reactants, each raised to the first power
Termolecular Reaction
an elementary step that involves three molecules
Transition State
the species temporarily formed by the reactant molecules as a result of the collision before they form the product (aka activated complex)
Unimolecular Reaction
an elementary step in which only one reacting molecule participates
