Balancing a chemical equation involves making sure that the number of atoms for each element is equal on both the reactant and product sides of the equation. Let's balance the given equation step-by-step:
[tex]\[ Mg + H_2O \rightarrow Mg(OH)_2 + H_2 \][/tex]
1. Identify the number of each type of atom on both sides of the equation:
- Reactants:
- Mg: 1 atom
- H: 2 atoms (from [tex]\(H_2O\)[/tex])
- O: 1 atom
- Products:
- Mg: 1 atom
- H: 2 atoms (from [tex]\(Mg(OH)_2\)[/tex])
- O: 2 atoms (from [tex]\(Mg(OH)_2\)[/tex])
2. Balance the atoms one element at a time:
- Magnesium (Mg):
The number of Mg atoms is already balanced (1 Mg atom on both reactant and product sides).
- Oxygen (O):
On the reactant side, there is 1 oxygen atom (from [tex]\(H_2O\)[/tex]). On the product side, there are 2 oxygen atoms (from [tex]\(Mg(OH)_2\)[/tex]).
To balance the oxygen atoms, we need 2 molecules of [tex]\(H_2O\)[/tex] on the reactant side:
[tex]\[ Mg + 2H_2O \rightarrow Mg(OH)_2 + H_2 \][/tex]
- Hydrogen (H):
Now, with 2 [tex]\(H_2O\)[/tex] molecules on the reactant side, we have 4 hydrogen atoms (2x H = 4 H).
On the product side, there are 2 hydrogen atoms in [tex]\(Mg(OH)_2\)[/tex] and 2 hydrogen atoms in [tex]\(H_2\)[/tex], which sums to 4 hydrogen atoms.
3. Check the Balance:
- Reactants:
- Mg: 1 atom
- H: 4 atoms (from 2 [tex]\(H_2O\)[/tex])
- O: 2 atoms (from 2 [tex]\(H_2O\)[/tex])
- Products:
- Mg: 1 atom
- H: 4 atoms (2 from [tex]\(Mg(OH)_2\)[/tex] + 2 from [tex]\(H_2\)[/tex])
- O: 2 atoms (all from [tex]\(Mg(OH)_2\)[/tex])
The balanced chemical equation is:
[tex]\[ Mg + 2H_2O \rightarrow Mg(OH)_2 + H_2 \][/tex]
This ensures that there is an equal number of each type of atom on both sides of the equation, following the law of conservation of mass.
