Openstax- Chemistry Chapter 12: Kinetics- vocab and equations

Activated Complex

Also transition state, unstable combination of reactant species representing the highest energy state pf a reaction system

Activation energy

energy necessary in order for a reaction to take place

Average Rate

rate of a chemical reaction computed as the ratio of a measured change in amount or concentration of substance to the time interval over which the change occured

Biomolecular reaction

elementary reaction involving the collision and combination of two reactant species

Catalyst

substance that increases the rate of a reaction without itself being consumed by the reaction

Collision theory

model that emphasizes the energy and orientation of molecular collisions to explain and predict reaction kinetics

Elementary Reaction

reaction that takes place precisely as depicted in its chemical equation

Half-life of a reaction

time required for half of a given amount of reactant to be consumed

Heterogeneous Catalyst

catalyst present in a different phase from the reactants, furnishing a surface at which a reaction can occur

Homogeneous catalyst

catalyst present in the same phase as the reactants

Initial rate

instantaneous rate of a chemical reaction at t=0 s (immediately after the reaction has begun)

Instantaneous rate

rate of a chemical reaction at any time, determined by the slope of the line tangential to a graph of a concentration as a function of time

Integrated rate law

equation that relates the concentration of a reactant to elapsed time of reaction

Intermediate

molecule or ion produced in one step of a reaction mechanism and consumed in another

Method of initial rates

use of a more explicit algebraic method to determine the orders in a rate law

Molecularity

number of reactant species (atoms, molecules, or ions) involved in an elementary reaction

Overall reaction order

Sum of the reaction orders for each substance represented in the rate law

Rate Constant (k)

proportionality constant in the relationship between reaction rate and concentrations of reactants

Rate expression

mathematical representation relating reaction rate changes to amount, concentration, or pressure of reactant or product species per unit of time

Rate law

Also rate equation, mathematical equation showing the dependence of reaction rate on the rate constant and the concentration of one or more reactants

Rate of reaction

measure of the speed at which a chemical reaction takes place

Rate-determining step

Also, rate-limiting step, slowest reaction in a reaction mechanism; determines the rate of the overall reaction

Reaction mechanism

stepwise sequence of elementary reactions by which a chemical change takes place

Reaction Order

value of an exponent in a rate law, expressed as an ordinal number

Termolecular reaction

elementary reaction involving the simultaneous collision and combination of three reactant species

Unimolecular reaction

elementary reaction involving the rearrangement of a single species to produce one or more molecules of product

Relative reaction rate equation

aA----> bB= -1/a(Δ[A]/Δt)= 1/b(Δ[B]/Δt)

Zero- Order Integrated Rate Law

First- Order Integrated Rate Law

Second- Order Integrated Rate Law

Zero- Order Half Life

First Order- Half Life

Second Order Half Life