Balance Equation Calculator Chemistry • PCM Notes
Enter unbalanced equation: Use = or → to separate reactants and products. Example: H2 + O2 = H2O or Fe + Cl2 = FeCl3

Balancing Chemical Equations

Quick Answer: Balancing chemical equations ensures the law of conservation of mass is obeyed. The number of atoms of each element must be equal on both the reactant and product sides.

Methods of Balancing

The algebraic method assigns variables to each coefficient and solves a system of linear equations. The inspection method (trial and error) works for simpler equations. This calculator uses the algebraic method with matrix solving for accuracy.

Solved Examples

Combustion of Methane
CH₄ + O₂ → CO₂ + H₂O
Balanced:
CH₄ + 2O₂ → CO₂ + 2H₂O
Formation of Ammonia
N₂ + H₂ → NH₃
Balanced:
N₂ + 3H₂ → 2NH₃
Rusting of Iron
Fe + O₂ → Fe₂O₃
Balanced:
4Fe + 3O₂ → 2Fe₂O₃

FAQs

What is the easiest method to balance chemical equations?

For simple equations, start by balancing elements that appear in only one compound on each side. Leave hydrogen and oxygen for last. For complex equations, the algebraic method is most reliable.

Why must chemical equations be balanced?

The law of conservation of mass states that matter cannot be created or destroyed. Balancing ensures the same number of each type of atom appears on both sides of the equation.

What if my equation contains polyatomic ions like SO₄²⁻?

Enter the formula as written (e.g., H2SO4). The calculator treats all atoms individually. For ions that stay intact on both sides, you can balance them as a group mentally.

Can this calculator balance redox reactions?

Yes, it balances atoms. However, for redox reactions in acidic or basic medium, you may need to also balance charges and add H₂O, H⁺, or OH⁻ manually after atom balancing.