Balance the following reactions :

Fe + H₂O → Fe₃O₄ + H₂↑

Balanced equation: 3Fe + 4H₂O → Fe₃O₄ + 4H₂

Step 1: Write the unbalanced equation

Fe + H₂O → Fe₃O₄ + H₂

Step 2: Compare the number of atoms of reactants with the number of atoms of products.

Step 3: Now, first we consider the element having unequal no. of atoms on both sides. Thus, first let us consider Fe atom. If we multiply 3 in the reactant (in Fe), we will get the equal number of atoms as in product (in Fe₃O₄)

Step 4: Write the resulting equation:

3Fe + H₂O → Fe₃O₄ + H₂

Step 5: Now check whether the equation is balanced or not by comparing the atoms

We find that the equation is not balanced yet. As the number of oxygen atoms is unequal on the two sides. Hence, balance the oxygen atom.

Step 6: If we multiply 4 in the reactant (in H₂O), we will get the equal number of oxygen atoms on both sides.

Step 7: Write the resulting equation:

3Fe + 4H₂O → Fe₃O₄ + H₂

Step 8: Now check whether the equation is balanced or not by comparing the atoms.

We find that the equation is not balanced yet. As the number of hydrogen atoms is unequal on the two sides.

Step 9: Now, we consider hydrogen atoms. If we multiply 2 in the product (in H₂), we will get the equal number of hydrogen atoms as in reactants.

Step 10: Write the resulting equation:

3Fe + 4H₂O → Fe₃O₄ + 2H₂

We find that the equation is balanced now.

Step 11: Write down the final balanced equation:

3Fe + 4H₂O → Fe₃O₄ + 2H₂