PHYSICAL CHEMISTRY IN BRIEF

CHAP. 9: CHEMICAL KINETICS [CONTENTS] 262

Chapter 9

Chemical kinetics

9.1 Basic terms and relations.

Chemical kinetics is focused on the study of chemical reactions prior to the attainment of
a chemical equilibrium. Kinetics studies in particular the rate of reactions, changes in the
reactants concentrations with time, and the mechanisms of reactions, i.e. their real course at
the molecular level. The field of chemical kinetics also embraces catalysis.

9.1.1 Rate of chemical reaction

Let us consider the general one-way chemical reaction

aA +bB +··· → sS +tT +···. (9.1)

Therate of consumptionof a reactant A is defined by the relation

rA=−

dcA

dτ

, [V, T]. (9.2)

Therate of formationof a product S is

rS=

dcS

dτ

, [V, T]. (9.3)