Balance hydrogen by adding a 3 in front of H₂.

Balance nitrogen by adding a 2 in front of NH₃.

Identify imbalances and adjust coefficients:

Record initial atom counts.

Create a chart listing atoms on both sides.

Now 2 H₂O molecules.

2 HCl molecules needed.

Final Balanced Equation: N₂ + 3 H₂ → 2 NH₃

Alters the compound identity (water vs. hydrogen peroxide).

Balanced Chemical Equation: 2 H₂ + O₂ → 2 H₂O

Adjust hydrogen by adding another H₂.

Add another molecule of water (H₂O):

Conclusion: Unbalanced due to oxygen.

On right: 2 hydrogen (H) atoms, 1 oxygen (O) atom.

On left: 2 hydrogen (H) atoms, 2 oxygen (O) atoms.

Balanced Chemical Equation: H₂ + Cl₂ → 2 HCl

Adjust molecule numbers to balance atom types:

Conclusion: Unbalanced equation.

On right: 1 hydrogen (H) atom, 1 chlorine (Cl) atom.

On left: 2 hydrogen (H) atoms, 2 chlorine (Cl) atoms.

Balanced Equation: Same number of each type of atom on both sides of the equation.

Unbalanced Equation: Different numbers of one or more types of atoms on either side of the equation.

Watch video resources for additional examples and exercises.

Engage with practice problems for mastery.

Steps to Balance

Only adjust coefficients in front of molecules, not subscripts.

Changing subscripts within a molecule (e.g., H₂O → H₂O₂):

Balancing the Equation

Analyzing the Chemical Equation

Balancing the Equation

Analyzing the Chemical Equation

Practice

Balancing Using Charts

Common Mistakes in Balancing

Example 2: Hydrogen and Oxygen Gas to Water

Example 1: Hydrogen and Chlorine Gas to Hydrochloric Acid

Key Concepts

Introduction to Balancing Chemical Equations