chemistry 3.2 - redox reactions

What is oxidisation?

Loss of electrons

What is reduction?

Gain of electrons

What is redox?

When oxidation’s and reduction happen simultaneously

What is an oxidising agent?

Get reduced by accepting electrons

What is a reducing agents?

Get oxidised by donating electrons

How di you work out what was oxidised / reduced during an equation?

By assigning the elements oxidisation numbers before and after the reaction

What is a disproportionate reaction?

A type of redox reaction where an element if a single species is oxidised and reduced simultaneously (e.g. Cl2 + OH- —> ClO- + Cl- + H2O where the Cl2 is oxidised (Cl2 —> ClO) and reduced (Cl2 —> Cl-) simultaneously)

What are ionic half equations?

Show oxidisation / reduction and can be combined = while equation once you have made number if electrons gained + lost equal so they can cancel out

What sometimes needs to be added to the half equations when making them a whole equation to make them balanced?

H+ ions and OH- ions

What are the steps for adding H+ and OH- ions to the half equations when making them a whole equation to make them balanced?

1. Identify which half equation needs to be changed

2. Add H2Os / OH-s to balance the Os

3. Add H+s to balance Hs

4. Balance charges by adding e-s