Reduction & Oxidation (Edexcel International A Level Chemistry): Revision Note

Reduction & Oxidation in s-, p- & d-Block Elements

• To recap, there are three definitions of oxidation and reduction  used in different branches of chemistry

• Oxidation and reduction can be used to describe any of the following processes

Definitions and Examples of Oxidation & Reduction

Use the acronym "Oil Rig" to help you remember the definitions of oxidation and reduction

• s-block elements are usually oxidised by losing electrons to form 1+ and 2+ ions

Na → Na⁺ + e^– 

Ca → Ca²⁺ + 2e^– 

• p-block metals typically undergo oxidation, by losing electrons, to form positive ions

  • p-block metal ions can have a charge that is consistent with their group of the Periodic Table

Al → Al³⁺ + 3e^– 

• p-block metal ions can also form common ions with a charge that is not consistent with their group

Sn → Sn²⁺ + 2e^– 

• p-block non-metals are usually reduced, by gaining electrons, to form negative ions 

  • p-block non-metals form ions with a charge that can be calculated by (the group number - 8)

F + e^- → F^– (group 7 - 8 = -1)

O + 2e^– → O^2- (group 6 - 8 = -2)

• d-block elements can form various ions due to their variable oxidation states

  • d-block elements will usually be oxidised, by losing electrons, to form positive ions, e.g. Cu²⁺, Cr³⁺, V⁵⁺