Aluminum oxide [tex]\left( \text{Al}_2\text{O}_3 \right)[/tex] and iron [tex]\left( \text{Fe} \right)[/tex] react according to the following equation:

[tex]\[
\text{Al}_2\text{O}_3 + \text{Fe} \rightarrow \text{Fe}_3\text{O}_4 + \text{Al}
\][/tex]

Balancing the equation requires inserting the correct coefficients to reflect that no atoms are gained or lost in the reaction. Which is the correct set of four coefficients, in order?

A. [tex]2, 8, 3, 6[/tex]
B. [tex]1, 3, 1, 2[/tex]
C. [tex]3, 9, 3, 6[/tex]
D. [tex]4, 9, 3, 8[/tex]



Answer :

To determine the correct coefficients for balancing the reaction equation, given as:

[tex]\[ \boxed{\square} \, Al_2O_3 + \boxed{\square} \, Fe \rightarrow \boxed{\square} \, Fe_3O_4 + \boxed{\square} \, Al \][/tex]

we need to ensure that the number of atoms for each element is the same on both sides of the equation.

Here are the steps to find the correct coefficients:

1. Analyze the initial reactants and products:
- Reactants: [tex]\(Al_2O_3\)[/tex] and [tex]\(Fe\)[/tex]
- Products: [tex]\(Fe_3O_4\)[/tex] and [tex]\(Al\)[/tex]

2. Set up the initial counts for each atom in the unbalanced equation:
- [tex]\(Al_2O_3\)[/tex]:
- 2 Aluminum (Al) atoms
- 3 Oxygen (O) atoms
- [tex]\(Fe_3O_4\)[/tex]:
- 3 Iron (Fe) atoms
- 4 Oxygen (O) atoms

3. Balance the elements one by one:

- First balance for aluminum (Al):
- On the left side, [tex]\(Al_2O_3\)[/tex] has 2 Al atoms.
- On the right side, Al needs to appear as a separate element. To balance Al atoms, we need 2 Al atoms on the right side.
- So, coefficient of Al on the right side should be 2.

- Now balance oxygen (O):
- From [tex]\(Al_2O_3\)[/tex], we have 3 oxygen atoms on the left side.
- From [tex]\(Fe_3O_4\)[/tex], we have 4 oxygen atoms. To balance 3 oxygen atoms from [tex]\(Al_2O_3\)[/tex] with 4 oxygen atoms from [tex]\(Fe_3O_4\)[/tex], we will look for simplifying the least common multiple (12 are the least common multiple of 3 and 4):
- We will balance 3[tex]\(Al_2O_3\)[/tex] on left side giving us total of [tex]\(3 \times 3 = 9\)[/tex] oxygen atoms.
- We will balance 3[tex]\(Fe_3O_4\)[/tex] on the right side giving us total of [tex]\(3 \times 4 = 12\)[/tex] oxygen atoms.
- Now, we will adjust the oxygen atoms by multiplying another compound of Fe.

- Balance iron (Fe):
- For every 3 [tex]\( Fe\)[/tex], we produce [tex]\(Fe_3O_4\)[/tex] having compound with 3 Fe.
- Therefore, balance by ensuring three Fe atoms combine giving 9 Fe on left side providing us :
- Fe appears on left side as (total [tex]\(9 Fe\)[/tex] required).

4. Summarize coefficients:
By balancing Ai, O, and Fe as per step you get this summarized step:

Looking at these set of steps again step by step your correct coefficient form is:

[tex]\[ \boxed{1}, \boxed{3}, \boxed{1}, \boxed{2} \][/tex]

Therefore, the correct set of coefficients is:
B. [tex]\(1, 3, 1, 2\)[/tex]


The balanced equation would be:
[tex]\[ \boxed{1} Al_2O_3 + \boxed{3} Fe \rightarrow \boxed{1} Fe_3O_4 + \boxed{2} Al \][/tex]

Thus, option B is the correct answer.