Redox Reactions

Redox reaction

Redox is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the actual or formal transfer of electrons between chemical species

Oxidation is loss of electrons

Reduction is gain of electrons

Tip: The initial letter shown in bold spell OILRIG. It is easier to remember it now

Half equations

A half-equation shows you what happens at one of the electrodes during electrolysis . Electrons are shown as e ^-. A half-equation is balanced by adding, or taking away, a number of electrons equal to the total number of charges on the ions in the equation.

Oxidation number

Oxidation number in simple terms can be described as the number that is allocated to elements in a chemical combination. The oxidation number is basically the count of electrons that atoms in a molecule can share, lose or gain while forming chemical bonds with other atoms of a different element.

Oxidation rules

1

The oxidation number of any uncombined element is zero. Eg: S8, Cl2 ,

2

In compounds many atoms or ions have fixed oxidation numbers

-Group 1= +1

-Group 2= +2

-Group 7= -1

3

The oxidation number of an element in a monoatomic ion is always the same charge

-Cl^-= -1

-Al^3+= +3

Oxidation

-Increase in oxidation number

-Oxidising agent increases the Ox no. of another atom and decreases in Ox no.

Reduction

-Decrease in oxidation number

-Reducing agent decreases the Ox no. of another atom and increases in Ox no.

Videos

Redox reactions and oxidation numbers

Balancing redox reactions with half equations

Balancing redox reaction and disproportion reaction

Oxidising and reducing agents

Page updated

Google Sites

Report abuse