Equation balancing and mass arithmetic. Not a procedure, not a safety assessment, and not a prediction that the reaction works. Every figure assumes the reaction goes exactly as written, to completion, with pure dry reagents and no side products. Nothing here checks whether it is thermodynamically possible, kinetically reasonable, or safe to attempt. Reference calculation only, verify before use. Open for the full scope limits.
What this tool actually does
Parses formulas, balances the equation by null-space linear algebra, and computes molar masses, mole ratios, limiting reactant and theoretical yield from the masses you enter. It is arithmetic on the equation you typed.
A balanced equation is a bookkeeping statement about atoms. It is not evidence that the reaction proceeds, that those are the products, or that the mixture is safe to make.
Not accounted for, at all
- Reagent purity, assay and hydration state. Weighing a hydrate as the anhydrous formula is a silent error this page cannot see.
- Solvent effects, incomplete reactions and side reactions.
- Catalyst requirements, thermodynamic feasibility and kinetics. An equation that balances may be impossible, or take a century.
- Safety hazards, incompatibilities, exotherms, pressure generation and gas evolution.
- Waste disposal, neutralisation and regulatory handling.
- Analytical measurement uncertainty, balance calibration and transfer losses.
Where the balance itself is not the answer
- Redox and multi-step reactions. The null-space solution is mathematically valid and may not be the chemically preferred pathway.
- Under-determined systems have infinitely many valid balances, and the tool shows one of them. The page flags this when it happens; the flag is the important output, not the coefficients.
- Theoretical yield is a ceiling, not an expectation. Real yield is lower, sometimes by a lot, and the gap is where the chemistry actually is.
Never use this for
- Planning or scaling up a reaction you have not run and reviewed, particularly anything exothermic, energetic or gas-evolving.
- Preparation of anything to be eaten, drunk, inhaled, injected or applied to a person or animal.
- Deciding that a mixture is safe, or that two reagents are compatible.
- Waste treatment, neutralisation or disposal quantities without the relevant Safety Data Sheets and local regulations.
- Analytical reporting, certificates of analysis, or any regulatory or compliance submission.
- Teaching material presented as authoritative without an instructor checking it.
Before you weigh anything
Verify all calculations against peer-reviewed references and analytical data, and read the Safety Data Sheet for every reagent and every product before use in any laboratory, production or compliance context. Work under a competent chemist and the safety regime of your institution, at a scale you have justified, with the hazard controls the SDS calls for.
Reaction Input
Enter an unbalanced chemical equation using standard notation (e.g., H2 + O2 -> H2O).