Chemical Equation Balancer

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Balanced Equation

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Enter an equation

Type a chemical equation above to balance it automatically.

History
โ‡‹ Redox half-reaction combiner (beta)

Enter balanced half-reactions with electrons (e-). The tool equalizes electrons and combines into a net reaction.

๐Ÿ“š Reaction database
TypeUnbalancedBalanced

1 What is a Chemical Equation?

A chemical equation is a symbolic representation of a chemical reaction. Reactants appear on the left side and products on the right, separated by an arrow (โ†’). Each substance is written as a chemical formula (e.g., Hโ‚‚O for water). The law of conservation of mass requires that every atom present in the reactants must also appear in the products โ€” nothing is created or destroyed, only rearranged.

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Key insight: Balancing an equation means finding the smallest set of integer coefficients that make atom counts equal on both sides. This tool uses Gaussian elimination on the atom matrix for a mathematically rigorous solution.

2 How to Balance Chemical Equations

Follow these four steps for any equation. This is the exact process our balancer automates:

1

Write Formulas

Write correct chemical formulas for all reactants and products. Do not change subscripts.

2

Count Atoms

Count atoms of each element on both sides. Include atoms inside parentheses.

3

Add Coefficients

Place whole-number coefficients before formulas to equalize counts. Start with metals.

4

Verify & Simplify

Double-check every element. Reduce coefficients to the smallest whole-number ratio.

3 Common Reaction Types

Combustion

Cโ‚ƒHโ‚ˆ + 5Oโ‚‚ โ†’ 3COโ‚‚ + 4Hโ‚‚O

Acid-Base

HCl + NaOH โ†’ NaCl + Hโ‚‚O

Synthesis

2Hโ‚‚ + Oโ‚‚ โ†’ 2Hโ‚‚O

Decomposition

2KClOโ‚ƒ โ†’ 2KCl + 3Oโ‚‚

Single Replacement

Zn + 2HCl โ†’ ZnClโ‚‚ + Hโ‚‚

Double Replacement

AgNOโ‚ƒ + NaCl โ†’ AgCl + NaNOโ‚ƒ

4 Redox Reactions Primer

Redox (reductionโ€“oxidation) reactions involve electron transfer. The substance that loses electrons is oxidized; the one that gains electrons is reduced. Use the half-reaction method to balance:

  1. Split into oxidation and reduction half-reactions
  2. Balance atoms other than O and H
  3. Balance O with Hโ‚‚O and H with Hโบ (acidic) or OHโป (basic)
  4. Balance charge with electrons (eโป)
  5. Equalize electrons between half-reactions and combine
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Tip: Use the Redox tab in our tool to enter your balanced half-reactions directly. It will equalize electrons and produce the net ionic equation automatically.