Chapter 2
General Kinetic Rules for Chemical
Reactions, Collisional,
and Intramolecular Processes
Abstract This chapter deals with basic information on kinetics for chemical
reactions, collisional, and intramolecular processes. Definitions of reaction and
process rates, equilibrium constants, partition functions of atoms, and molecules are
introduced. Kinetic types of simple reactions, as well as complex reactions and the
steady-state method, are discussed.
2.1 Rates of Reaction, Collisional, and Spontaneous
Processes. Rate Constants. Kinetic Types of Simple
Processes
According to IUPAC Compendium of Chemical Terminology [1], a chemical
reaction is a process that results in the interconversion of chemical species.
A process of interaction of an oxygen atom in the first excited state, O(
1 D), with a
H 2 O molecule in which two OH radicals are formed, i.e., the chemical composition
changes:
O
1 D
À Á þ H 2 O e
X
1
A 1
À
Á ! 2OH X
2 P; v X; J X
À
Á
ð2:1:1aÞ
is an example of chemical reactions.
In principle, electronic deactivation of an O(
1 D) atom in a collision with a H 2 O
molecule
O
1 D
À Á þ H 2 O e
X
1
A 1
À
Á ! O
3 P
À Á þ H 2 O e
X
1
A 1 ; v X
À
Á
ð2:1:2Þ
can occur. One should note that electronic deactivation of an O(
1 D) atom in a
collision with an O 2 molecule
O
1 D
À Á þ O 2 X
3
X À
g
; v X ¼ 0
! O
3 P
À Á þ O 2 b
1
X þ
g
; v b
ð2:1:3Þ
© Springer Nature Switzerland AG 2021
A. Pravilov, Gas-Phase Photoprocesses, Springer Series in Chemical Physics 123,
https://doi.org/10.1007/978-3-030-65570-9_2
5
General Kinetic Rules for Chemical
Reactions, Collisional,
and Intramolecular Processes
Abstract This chapter deals with basic information on kinetics for chemical
reactions, collisional, and intramolecular processes. Definitions of reaction and
process rates, equilibrium constants, partition functions of atoms, and molecules are
introduced. Kinetic types of simple reactions, as well as complex reactions and the
steady-state method, are discussed.
2.1 Rates of Reaction, Collisional, and Spontaneous
Processes. Rate Constants. Kinetic Types of Simple
Processes
According to IUPAC Compendium of Chemical Terminology [1], a chemical
reaction is a process that results in the interconversion of chemical species.
A process of interaction of an oxygen atom in the first excited state, O(
1 D), with a
H 2 O molecule in which two OH radicals are formed, i.e., the chemical composition
changes:
O
1 D
À Á þ H 2 O e
X
1
A 1
À
Á ! 2OH X
2 P; v X; J X
À
Á
ð2:1:1aÞ
is an example of chemical reactions.
In principle, electronic deactivation of an O(
1 D) atom in a collision with a H 2 O
molecule
O
1 D
À Á þ H 2 O e
X
1
A 1
À
Á ! O
3 P
À Á þ H 2 O e
X
1
A 1 ; v X
À
Á
ð2:1:2Þ
can occur. One should note that electronic deactivation of an O(
1 D) atom in a
collision with an O 2 molecule
O
1 D
À Á þ O 2 X
3
X À
g
; v X ¼ 0
! O
3 P
À Á þ O 2 b
1
X þ
g
; v b
ð2:1:3Þ
© Springer Nature Switzerland AG 2021
A. Pravilov, Gas-Phase Photoprocesses, Springer Series in Chemical Physics 123,
https://doi.org/10.1007/978-3-030-65570-9_2
5