Question

Identify the oxidation state for each atom in the following reaction:

4Fe + 3O2 → 2Fe2O3

a. Elemental iron (Fe)
b. Elemental oxygen (O2)
c. One iron atom in Fe2O3
d. One oxygen atom in Fe2O3

Answer 1

a) 0 because Fe is uncharged
b) 0 because O in O2 is uncharged as well
c) +3 because each Fe atom lost 3 electrons
d) -2 because each oxygen aim gained 2 elections

Answer 2

Answer:   a. Elemental iron (Fe) : 0

b. Elemental oxygen $(O_2)$ : 0

c. One iron atom in $Fe_2O_3$: +3

d. One oxygen atom in $Fe_2O_3$ : -2

Explanation:

Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.

In neutral ionic compound , the oxidation states are exchanged to give the molecular formula. Thus in $Fe_2O_3$ iron has oxidation state of +3 and oxygen has oxidation state of -2.

For the reaction :

$4Fe+3O_2\rightarrow 2Fe_2O_3$

On reactant side:

Oxidation state of iron in elemental state = 0

Oxidation state of oxygen = 0

On product side:

Oxidation state of iron = +3

Oxidation state of oxygen = -2