To determine the correct balanced equation for the reaction between iron (Fe) and atmospheric oxygen (O₂) to form iron oxide (Fe₂O₃), we need to ensure that the number of atoms for each element is the same on both the reactant and product sides of the equation. Here’s a step-by-step process to balance the equation:
1. Write the unbalanced equation:
[tex]\[
Fe + O_2 \rightarrow Fe_2O_3
\][/tex]
2. Identify the number of atoms of each element on both sides of the equation:
For the reactants:
- Iron (Fe): 1 atom
- Oxygen (Oâ‚‚): 2 atoms
For the products:
- Iron (Fe): 2 atoms (in Fe₂O₃)
- Oxygen (O): 3 atoms (in Fe₂O₃)
3. Balance the iron (Fe) atoms:
To balance the iron atoms, we need 4 atoms of Fe on the reactant side, because \(2 \times Fe_2O_3\) will give us 4 Fe atoms on the product side. This can be achieved by placing a coefficient of 4 before Fe:
[tex]\[
4 Fe + O_2 \rightarrow 2 Fe_2O_3
\][/tex]
4. Balance the oxygen (O) atoms:
Now we have 6 oxygen atoms on the product side (since \(2 \times Fe_2O_3\) results in \(2 \times 3\) O atoms). To balance the oxygen atoms, we need 6 oxygen atoms on the reactant side. Since each Oâ‚‚ molecule contains 2 oxygen atoms, placing a coefficient of 3 before Oâ‚‚ will give us 6 oxygen atoms:
[tex]\[
4 Fe + 3 O_2 \rightarrow 2 Fe_2O_3
\][/tex]
5. Verify the balance:
- Reactants:
- Fe: 4 atoms
- O: \(3 \times 2 = 6\) atoms
- Products:
- Fe: \(2 \times 2 = 4\) atoms
- O: \(2 \times 3 = 6\) atoms
The equation is balanced, with 4 iron atoms and 6 oxygen atoms on both sides.
Therefore, the correct balanced equation for this reaction is:
[tex]\[
4 Fe + 3 O_2 \rightarrow 2 Fe_2O_3
\][/tex]
Thus, the correct answer is:
A. [tex]\( 4 Fe + 3 O_2 \rightarrow 2 Fe_2O_3 \)[/tex]
