Integrated Rate Laws and Reaction Half-Lives

Flashcards on Integrated Rate Laws and Reaction Half-Lives

Integrated Rate Law

Obtained by integration of the differential rate law; provides insight into how the concentration of a reactant changes with time.

Zero Order Rate Law

Rate = k; [A]t = -kt + [A]0; Plot [A] vs t to get a straight line with slope = -k; t1/2 = [A]0 / 2k; Units: M s-1

First Order Rate Law

Rate = k[A]; ln[A]t = -kt + ln[A]0; Plot ln[A] vs t to get a straight line with slope = -k; t1/2 = 0.693/k; Units: s-1

Second Order Rate Law

Rate = k[A]^2; 1/[A]t = kt + 1/[A]0; Plot 1/[A] vs t to get a straight line with slope = k; t1/2 = 1 / (k[A]0); Units: M-1 s-1

Reaction Half-Life (t1/2)

The time it takes for half of the reactant (A) to be consumed.

First Order Half-Life

t1/2 = 0.693 / k; The half-life is constant and does not depend on the initial concentration of the reactant.