Chemical Equation Balancer

Conservation of atoms

Balancing a chemical equation does not change the species formulas. Only the coefficients in front of them are chosen. The total number of atoms of each element must match on the reactant and product sides. For example, H2 + O2 → H2O becomes 2 H2 + O2 → 2 H2O. Both sides then contain four hydrogen atoms and two oxygen atoms.

Input format and scope

Write formulas using ordinary digits and correct capitalization. Groups such as Ca(OH)2 are supported. Omit initial coefficients, phase labels and ionic charges. The calculator sets up one conservation equation per element and solves the system using exact fractions. If the data do not determine a unique coefficient ratio, no arbitrary answer is returned. An atomic balance alone gives no information about chemical stability or experimental safety.

Verify coefficients by counting atoms

Enter Al + O2 in the Reactants field and Al2O3 in the Products field. Oxygen appears in groups of three in the product and two in the reactant. To reach a common total of six oxygen atoms, choose product coefficient 2 and oxygen coefficient 3. This product quantity contains four aluminium atoms, so the Al coefficient on the left is 4. The result is 4 Al + 3 O2 → 2 Al2O3. Both sides contain four Al and six O atoms. This is not a recommendation for a laboratory experiment.

A coefficient multiplies every atom in the formula. Changing a subscript instead specifies a different substance. If all coefficients share a divisor, divide all of them by it to obtain the smallest whole number ratio. Changing just one coefficient breaks the balance.

Capitalisation of element symbols matters. Use ordinary digits for subscripts and formulas rather than substance names. An element absent from one side cannot be conserved with positive coefficients on the other. Do not force a result by inventing products. Ionic or electron reactions need more than atom counting, since charge conservation requires a separate method.

Frequently asked questions

How do you balance a chemical equation?

For example, solving the atom conservation equations balances reactants Fe + O2 and product Fe2O3 as 4 Fe + 3 O2 → 2 Fe2O3. Coefficients are reduced to the smallest positive integers without changing formula subscripts, and this formal atom balance does not establish whether the reaction occurs, how fast it proceeds or its energy requirement.

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