Redox reactions

Redox reactions: in which changes in oxidation numbers of atoms in involved species occur.

Those reactions can often be interpreted as transferences of electrons between different molecular sites or species.

An example of a redox reaction is:

2 S₂O₃²⁻_(aq) + I_2(aq) → S₄O₆²⁻_(aq) + 2 I⁻_(aq)

In which I₂ is reduced to I^- and S₂O₃^2- (thiosulfate anion) is oxidized to S₄O₆^2-.