# How do you determine the oxidizing agent in a reaction?

Dec 23, 2016

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:

$C \left(g\right) + {O}_{2} \left(g\right) \rightarrow C {O}_{2} \left(g\right)$

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,

$N a \rightarrow N {a}^{+} + {e}^{-}$

$\frac{1}{2} C {l}_{2} + {e}^{-} \rightarrow C {l}^{-}$

And overall, we simply sum the reactions directly:

$N a + \frac{1}{2} C {l}_{2} \rightarrow N {a}^{+} C {l}^{-}$

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