Oxidation, reduction & redox reactions

What is the rule for assigning oxidation states [4]?

• elements have oxidation states of 0

• simple and complex ions oxidation state is equal to its overall charge

• the sum of oxidation states in a compound is 0

What are the exemptions to the oxidation state rules [5]?

• hydrogen has an oxidation state of -1 in metal hydrides

• oxygen has an oxidation state of -1 in peroxides

• oxygen has an oxidation state of +2 in fluorine compounds

• halogens have an oxidation state of +5 when binded to oxygen

• halogen have an oxidation state of -1 when binded to fluorine

How do you balance/write half equations [2]?

• Balance the oxygen by adding H2O

• Balance the hydrogens by adding H+

How do you determine whether an equation is an oxidation or reduction reaction [2]?

• Oxidation = electrons are on the products side.

• Reduction = electrons are on the reactants side.