Lesson 1 of 3

Balancing Chemical Equations

Learn to balance chemical equations using visual models and interactive tools.

Core48 min

Balancing Chemical Equations

Conservation of Mass

Atoms are neither created nor destroyed in chemical reactions. This fundamental law means:

The number of atoms of each element must be equal on both sides
Mass is conserved throughout the reaction

Balancing Steps

1. Write the unbalanced equation with correct formulas 2. Count atoms of each element on both sides 3. Add coefficients (whole numbers in front) - never change subscripts! 4. Balance one element at a time, saving hydrogen and oxygen for last 5. Check your work by counting all atoms again

Example

Unbalanced: $\text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O}$

Balanced: $2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$

Check:

Left: 4 H, 2 O
Right: 4 H, 2 O ✓

Watch: How to Balance Equations

14 min · watch

How to Balance Chemical Equations

Watch this comprehensive tutorial on balancing chemical equations step-by-step.

Learn systematic approaches to balance even complex equations with confidence.

Read: Balancing Strategy Guide

11 min · read

Strategic Balancing

Example: Combustion of Methane

Unbalanced: $\text{CH}_4 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O}$

Step 1: Balance C → Already balanced (1 on each side)

Step 2: Balance H → Add coefficient 2 to $\text{H}_2\text{O}$ $\text{CH}_4 + \text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$

Step 3: Balance O → Add coefficient 2 to $\text{O}_2$

Balanced: $\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}$

Check:

C: 1 = 1 ✓
H: 4 = 4 ✓
O: 4 = 4 ✓

Interactive: Equation Balancer

18 min · practice

Use visual atom models to balance equations interactively!

Practice: Balance These Equations

5 min · quiz

Question

Balance: $\text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O}$ . What coefficient goes in front of $\text{H}_2\text{O}$ ?

Next Lesson

Balancing Chemical Equations

Conservation of Mass

Atoms are neither created nor destroyed in chemical reactions. This fundamental law means:

The number of atoms of each element must be equal on both sides
Mass is conserved throughout the reaction

Balancing Steps

Example

Unbalanced: $\text{H}_2 + \text{O}_2 \rightarrow \text{H}_2\text{O}$

Balanced: $2\text{H}_2 + \text{O}_2 \rightarrow 2\text{H}_2\text{O}$

Check:

Left: 4 H, 2 O
Right: 4 H, 2 O ✓

Example: Combustion of Methane

Unbalanced:

\text{CH}_4 + \text{O}_2 \rightarrow \text{CO}_2 + \text{H}_2\text{O}

Step 1: Balance C → Already balanced (1 on each side)

Step 2: Balance H → Add coefficient 2 to

\text{H}_2\text{O}

\text{CH}_4 + \text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}

Step 3: Balance O → Add coefficient 2 to

\text{O}_2

Balanced:

\text{CH}_4 + 2\text{O}_2 \rightarrow \text{CO}_2 + 2\text{H}_2\text{O}

Check:

C: 1 = 1 ✓

H: 4 = 4 ✓

O: 4 = 4 ✓