# How do we represent the formation of FeS by the redox reaction of iron and sulfur?

Mar 6, 2017

$\text{Oxidation is the formal loss of electrons........}$

#### Explanation:

And thus, when zerovalent, i.e. elemental, iron is oxidized, we represent the oxidation on these terms:

$F e \rightarrow F {e}^{2 +} + 2 {e}^{-}$ $\left(i\right)$

On the other hand, $\text{reduction is the formal gain of electrons}$. For sulfur we have:

$S + 2 {e}^{-} \rightarrow {S}^{2 -}$ $\left(i i\right)$

We conceive that iron and sulfur undergo formal electron transfer, so we add reactions $\left(i\right) + \left(i i\right)$ so that electrons do not appear in the final equation:

$F e + S \rightarrow F e S$

And thus in the reverse reaction, $F {e}^{2 +}$ is REDUCED to give elemental iron.

We would cross multiply the redox equations if there were different numbers of electrons involved in the individual redox reactions.

If iron were oxidized to $F {e}^{3 +}$, how would you represent the redox reaction?