Page 4 Flashcards
Chemical kinetics
The study of the rate at which chemical reactions occur
Reaction order
The sum of the powers of the concentrations of reactants in the rare law
Half-life
The time required to turn half of a reactant into products; reaction order dependent
Zero order
Rate of reaction does not depend on amount of reactant; as the reaction proceeds, the half-life decreases
First order
If the reactant is doubled, the rate of reaction doubles; as the reaction proceeds the half life doesn’t change
Second order
If the reactant is doubled the rate of reaction quadruples; as the reaction proceeds, the half-life increases.
Reaction mechanism
The sequence of steps of elementary reactions by which the overall chemical reaction occurs.
Molecularity
The number of molecules, or ions, that participate in the rate determining step of a reaction mechanism.
Arrhenius equation
Relates temperature to reaction rates ;
Lnk = - Ea/RT + lnA
Equilibrium
A dynamic state in which the rates of the tor are and reverse reactions are equal; no net change ; 🔺G = 0 , E_cell =0
Equilibrium constant expression
The ratio of the concentrations of the products, raised to the power of their coefficients, over the reactants , raised to the power of their coefficients
LeChatelier’s principle
If stress is applied to a system at equilibrium, the system will shift to reduce the stress
Reactant quotient
Q; measures the relative amounts of products and reactants present during a reaction at a particular point in time; if Q=K , reaction at equilibrium
Activity
Molarity of a solution; partial pressures of a gas; and one for solids and liquids.
