Chemical Kinetics Equations

Reaction Rate

Rate = concentration of A at time t2 - concentration of A at t1 / t2 - t1

Reaction Order

Rate=k[A]^n[B]^m

Overall Reaction Order

The sum of the exponents (n+m)

First Order Rate Law

Rate=k[A]

First Order Integrated Rate Law

ln[A]=-kt+ln[A]_0

First Order Half Life

t_1/2=0.693/k

Plot needed to give a straight line (first order)

ln[A] versus t

Second Order Rate Law

Rate=k[A]^2

Second Order Integrated Rate Law

1/[A]=kt+1/[A]_0

Second Order Half Life

t_1/2=1/(k[A]_0)

Plot needed to give a straight line (second order)

1/[A] versus t

Zero Order Rate Law

Rate=k[A]^0 or Rate=k

Zero Order Integrated Rate Law

[A]=-kt+[A]_0

Zero Order Half Life

t_1/2=[A]_0/2k

Plot needed to give a straight line (zero order)

[A] versus t

Arrhenius Equation

k=Ae^-E_a^/RT

Linear Form of Arrhenius Equation

ln(k)=-E_a/R(1/T)+ln(A)