Consider the reaction of water with F2 and suggest, in terms of oxidation and reduction, which species are oxidized/reduced.
The reaction between fluorine and water can be represented as:
`2F_(2(g)) + 2H__2O_(l) -> 4H_((aq))^+ + 4F_((aq))^- + O_(2(g))`
This is an example of a redox reaction as water is getting oxidized to oxygen, while fluorine is being reduced to fluoride ion.
The oxidation numbers of various species can be represented as:
Fluorine is reduced from zero to (– 1) oxidation state. A decrease in oxidation state indicates the reduction of fluorine.
Water is oxidized from (– 2) to zero oxidation state. An increase in oxidation state indicates oxidation of water.
2F2(ag) + 2H20(l)—————> O2(g) + 4H+(aq) + 4F(aq)
In this reaction water acts as a reducing agent and itself gets oxidised to O2 while F2 acts as an oxidising agent and hence itself reduced to F– ions.