Redox Reactions

A loss of electrons is called OXIDATION

A gain of electrons is called REDUCTION

When there is a loss and a gain of electrons, this is called a REDOX reaction

An oxidising agent accepts electrons and gets reduced

A reducing agent donates electrons and gets oxidised

Oxidation State Rules -

• All atoms are treated as ions, even if they are covalently bonded
• Uncombined elements have an oxidation states of 0 (this applies to diatomic elements, like oxygen, hydrogen, fluorine etc.)
• In compounds, the overall oxidation state is equal to the charge
• The oxidation state of a mono atomic ion is the same as the charge
• Combined oxygen is nearly always -2
• Combined hydrogen is +1

Ionic Half equations show reduction or oxidation

You can combine half equations for different oxidising or reducing agents together to make full equations for redox reactions

When writing half equations, remember to balance them out by adding electrons. Then when you have 2 half equations, you need there to be the same amount of electrons added in each equation, so you can multiply one half equation to make the electrons equal