Question

Determine the oxidation number of each atom in the following compounds: sodium chloride and iron oxide.

Answer 1

Oxidation number of each atom

1. Sodium chloride NaCl

Sodium is in group 1 in the periodic table so it always going to have +1 charge for its oxidation number.

chlorine in group 7 called halogen gas will almost always have -1 charge for its oxidation number except for very few exceptions.

2. iron oxide Fe(2)O(3)

Oxygen usually have the oxidation number of -2 unless bonded to F or H(2)O(2). We have 3 Oxygen atoms so 3*(-2) = -6

Now we have 2 iron atoms and we need total +6 charge of the iron so that 2*x = +6 and that is +3.

So the oxidation number of Fe is +3.