Question

How many oxygen atoms are present on the reactant side of the chemical equation $4Fe+3{{O}_{2}}\to 2F{{e}_{2}}O$ ?

Answer 1

To know the number of oxygen atoms on the reactant side, we must first balance the chemical equation. And then we can easily find the number of oxygen atoms in the reactant side.

Complete Step-by-Step Solution
Firstly, let us write the correct chemical equation and then later we will balance it as and when required.
$4Fe+3{{O}_{2}}\to 2F{{e}_{2}}{{O}_{3}}$
This is the correct chemical equation for the reaction. And as we can observe that the number of iron and oxygen atoms in the reactant side is equal to that of the product side. This confirms that the given chemical equation is balanced.
Now, the question is asked to count the number of oxygen atoms on the reactant side. As we can observe on the reactant side that there are three ${{O}_{2}}$ molecules. That means that there are a total of six oxygen atoms.
Hence, there are a total of six oxygen atoms present at the reactant side of the given chemical equation.

Additional Information
The addition of stoichiometric coefficients to the reactants and products includes balancing chemical equations. This is important because on the reactant side and the product side of the equation, a chemical equation must obey the law of mass conservation and the law of constant proportions, i.e., the same number of atoms of each element must exist.

Note
To solve these types of problems, students should proceed by writing the balanced chemical equation and then only move ahead for the next step. Balancing of a chemical equation plays an important role in explaining most aspects of the chemical equation.