Question

How do you determine the oxidizing agent in a reaction?

Answer 1

The oxidizing agent is the species that accepts electrons.........

Explanation:

.........and thus is the species that is reduced in a redox reaction.

If we look at, say, the combustion of coal:

`C(g) +O_2(g) rarr CO_2(g)`

Zerovalent oxygen gas oxidizes zerovalent carbon to give `""^(+IV)CO_2^(-II)`, in which the oxygen has been formally reduced, and the carbon formally oxidized.

And of course we can artificially split these reactions up to give separate oxidation/reduction reactions, for instance,

`Na rarr Na^(+) + e^(-)`

`1/2Cl_2 +e^(-) rarr Cl^-`

And overall, we simply sum the reactions directly:

`Na +1/2Cl_2 rarr Na^(+)Cl^-`

And thus, again, the oxidizing agent is the brute that accepts electrons, which here is clearly?