How to balance chemical equations step by step

How to balance chemical equations simple explanation.

A balanced chemical equation is a representation of a chemical reaction that shows the same number of each type of atom on both the reactant and product sides. This balance reflects the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.

Components of a Balanced Chemical Equation

Reactants: The substances that undergo a chemical change (on the left side of the equation).

Products: The substances formed as a result of the chemical reaction (on the right side of the equation).

Coefficients: Numbers placed before the compounds to indicate how many molecules or moles of each substance are involved in the reaction.

Balancing chemical equations is essential in chemistry to ensure that the law of conservation of mass is followed, meaning that the number of atoms for each element must be the same on both sides of the equation. Here’s a step-by-step guide to balancing chemical equations.

Step 1: Write the Unbalanced Equation

Start with the unbalanced chemical equation. For example:

$$\text{C}_3\text{H}_8 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O}$$

Step 2: Count the Atoms

Count the number of atoms of each element on both sides of the equation.

Reactants (left side):

• C: 3
• H: 8
• O: 2

Products (right side):

• C: 1 (in CO₂)
• H: 2 (in H₂O)
• O: 3 (2 in CO₂ + 1 in H₂O)

Step 3: Balance One Element at a Time

Start balancing elements that appear in only one reactant and one product first.

Balance Carbon (C):

To balance carbon, put a coefficient of 3 in front of CO₂:

$$\text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + \text{H}_2\text{O}$$

Updated Counts:

• Reactants: C: 3, H: 8, O: 2
• Products: C: 3, H: 2, O: 7 (6 from CO₂ and 1 from H₂O)

Balance Hydrogen (H):

To balance hydrogen, put a coefficient of 4 in front of H₂O:

$$\text{C}_3\text{H}_8 + \text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$$

Updated Counts:

• Products: C: 3, H: 8, O: 10 (6 from CO₂ and 4 from H₂O)

Balance Oxygen (O):

Now count the oxygen atoms. You have 10 oxygen atoms on the product side. Since O₂ has 2 atoms of oxygen, place a coefficient of 5 in front of O₂:

$$\text{C}_3\text{H}_8 + 5\text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$$

Step 4: Verify the Balance

Now verify that the number of atoms for each element is the same on both sides:

Reactants:

• C: 3
• H: 8
• O: 10 (from 5 O₂)

Products:

• C: 3 (from 3 CO₂)
• H: 8 (from 4 H₂O)
• O: 10 (6 from 3 CO₂ + 4 from 4 H₂O)

Final Balanced Equation

The balanced equation is:

$$\text{C}_3\text{H}_8 + 5\text{O}_2 \rightarrow 3\text{CO}_2 + 4\text{H}_2\text{O}$$

Summary of Steps:

1. Write the unbalanced equation.
2. Count the atoms of each element on both sides.
3. Balance one element at a time using coefficients.
4. Verify the balance and adjust if necessary.