Balance a chemical equation

Balance atom counts across a chemical equation with integer stoichiometric coefficients.

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ToolChemical Equation Balancer
Input
Output
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How it works

Formula counts form a stoichiometric matrix, rational elimination finds a null-space coefficient ratio, and denominators are cleared before the integer vector is reduced. Every element count is conserved in the resulting equation.

  • All species receive positive coefficients.
  • Atom balance does not prove chemical feasibility or ionic charge balance.

Worked example

Combustion of methane
CH4 + O2 -> CO2 + H2O
Input
											Reactants: CH4 + O2
Products: CO2 + H2O
Output
												Balanced equation: CH4 + 2O2 -> CO2 + 2H2O
Reactant coefficients: 1, 2
Product coefficients: 1, 2
Elements checked: C, H, O

When to use this

Classes balance combustion, lab protocols check coefficients, and stoichiometry worksheets use them for limiting reagent.

Edge cases

  • Malformed brackets or element symbols are rejected before solving.
  • Multiple free variables make an equation underdetermined.
  • Atom balance alone does not prove an ionic reaction is charge balanced.

References