Reactions & Stoichiometry

Chemical Equation Balancer

Balance molecular or ionic equations with verified whole-number coefficients.

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Enter values

Examples
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Results

Ready to calculate

Your result, units, method, and version information will appear here.

How to use this calculator

  1. Enter reactants on the left and products on the right.
  2. Use a plus sign between species and an arrow between the reaction sides.
  3. Include ionic charges and phases when they are known.
  4. Calculate and review the verified smallest integer coefficients.

Formula and variables

A·x = 0, with x normalized to the smallest positive integers

SymbolMeaningUnit
Aelement/charge conservation matrixinteger counts
xspecies coefficient vectordimensionless

Worked example

For H2 + O2 -> H2O, exact reduction gives the coefficients 2, 1, and 2. Verification confirms equal hydrogen and oxygen counts.

Interpretation

Each coefficient is the smallest positive integer in a verified one-dimensional conservation solution. Underconstrained reactions are reported instead of choosing an arbitrary answer.

Common mistakes

  • Do not omit a reaction side.
  • Use spaces around + so ionic charge remains unambiguous.
  • Do not expect automatic acidic/basic half-reaction completion.

Frequently asked questions

Can the calculator balance ionic equations?

Yes. Enter each ionic charge. The calculator conserves both elements and net charge.

Does the calculator change chemical subscripts?

No. It changes coefficients only. A changed subscript would identify a different substance.

Why can an equation be underconstrained?

Some species sets permit more than one independent balance. The tool reports this condition instead of choosing an arbitrary result.

Can I use scientific notation?

Yes. Enter values such as 6.022e23 or 1.0e-6 in a numeric field.

How should I round the result?

Keep extra digits during the calculation. Round the final result to the precision required by your data.

Sources