In the equation, #2Al + 2Fe^(3+) + 3O^(2-) -> 2Fe + 2Al^(3+) + 3O^(2-)#m which element has been oxidized?
1 Answer
The aluminum (aluminium?) atom is oxidized into an ion.
Explanation:
To determine which particle has been oxidized, you look for a change in the oxidation number of the particles. Whenever a particle increases in oxidation number, that substance has been oxidized.
In case you are uncertain about oxidation numbers, here is a (partial) explanation:
The oxidation number of any element in its elementary form is zero.
The oxidation number of any ion is equal to the charge on that ion.
That will be enough for this question.
We see that during the reaction, the aluminum changes from being an atom (in its elementary form) with oxidation number zero, to an ion of charge +3, meaning its oxidation number has increased by three. Therefore it has been oxidized.
(This change can only happen if the aluminum atom has lost three electrons, and electron loss is (by definition) oxidation.)
