To balance the chemical equation for the formation of magnesium oxide, you need to ensure that the number of atoms for each element is equal on both the reactant and product sides of the equation.
The exact balanced equation for magnesium reacting with oxygen to form magnesium oxide is:
2Mg + O₂ → 2MgO
Balancing a chemical equation ensures adherence to the Law of Conservation of Mass, which states that matter cannot be created or destroyed. For the reaction where magnesium (Mg) combines with oxygen gas (O₂) to produce magnesium oxide (MgO), the process is straightforward.
As highlighted in the reference, the reaction involves magnesium plus oxygen giving us magnesium oxide. This translates to the unbalanced chemical equation:
Mg + O₂ → MgO
Let's break down the balancing process step-by-step:
Step 1: Write Down the Unbalanced Equation
First, clearly write out the reactants and products in their chemical formulas:
Mg (s) + O₂ (g) → MgO (s)
- Mg: Magnesium metal
- O₂: Diatomic oxygen gas (oxygen naturally exists as O₂ molecules)
- MgO: Magnesium oxide (the product formed)
Step 2: Count the Atoms for Each Element on Both Sides
Create a simple table to keep track of the number of atoms for each element on both the reactant (left) and product (right) sides of the equation.
| Element | Number of Atoms on Reactant Side | Number of Atoms on Product Side |
|---|---|---|
| Mg | 1 | 1 |
| O | 2 | 1 |
From the table, we can see that Magnesium (Mg) is balanced, but Oxygen (O) is not. There are 2 oxygen atoms on the reactant side and only 1 on the product side.
Step 3: Balance the Oxygen Atoms
To balance the oxygen atoms, we need to have 2 oxygen atoms on the product side. We can achieve this by placing a coefficient of 2 in front of the MgO molecule. Remember, you can only change coefficients, not the subscripts within a chemical formula.
Mg + O₂ → 2MgO
Now, let's update our atom count table:
| Element | Number of Atoms on Reactant Side | Number of Atoms on Product Side |
|---|---|---|
| Mg | 1 | 2 (from 2MgO) |
| O | 2 | 2 (from 2MgO) |
By balancing oxygen, we've now unbalanced magnesium.
Step 4: Balance the Magnesium Atoms
Currently, we have 1 magnesium atom on the reactant side and 2 on the product side. To balance magnesium, we need to place a coefficient of 2 in front of the Mg on the reactant side.
2Mg + O₂ → 2MgO
Let's do a final check of the atom count:
| Element | Number of Atoms on Reactant Side | Number of Atoms on Product Side |
|---|---|---|
| Mg | 2 | 2 |
| O | 2 | 2 |
Step 5: Verify the Balanced Equation
All atoms are now balanced on both sides of the equation.
2Mg + O₂ → 2MgO
This balanced equation accurately represents the chemical reaction where two atoms of magnesium react with one molecule of oxygen gas to produce two molecules of magnesium oxide. Understanding how to balance these equations is fundamental in chemistry, allowing for accurate stoichiometric calculations in various chemical processes.
