Rust (Fe2O3) forms on abandoned cars such as the one in this photo through a series of reactions between iron in the car and oxygen in the atmosphere.

Question

The unbalanced chemical equation for this reaction is

Fe(s) + O2(g) –> Fe₂O₃(s)

How many electrons are transferred in this oxidation–reduction reaction?

________ electrons

Answer 1

4Fe(s) + 3O₂(g) ==> 2Fe₂O₃(s) ... balanced equation

Looking at the half reaction for this, we have...

4Fe(s) ==> 4Fe³⁺ + 12e- ... oxidation half reaction

3O₂(g) + 12e- ===> 6O^2- ... reduction half reaction

Looks like 12 electrons are transferred in this oxidation-reduction reaction