Example Data Table
| Unbalanced equation | Balanced equation | Use case |
|---|
| H2 + O2 -> H2O | 2H2 + O2 → 2H2O | Basic combustion |
| Fe + O2 -> Fe2O3 | 4Fe + 3O2 → 2Fe2O3 | Oxidation example |
| C2H6 + O2 -> CO2 + H2O | 2C2H6 + 7O2 → 4CO2 + 6H2O | Fuel reaction |
| Al + HCl -> AlCl3 + H2 | 2Al + 6HCl → 2AlCl3 + 3H2 | Single replacement |
| Ca(OH)2 + H3PO4 -> Ca3(PO4)2 + H2O | 3Ca(OH)2 + 2H3PO4 → Ca3(PO4)2 + 6H2O | Acid base reaction |
Formula Used
For a reaction aA + bB → cC + dD, each element must have equal totals on both sides.
Element balance: a × atoms(A,e) + b × atoms(B,e) = c × atoms(C,e) + d × atoms(D,e).
The calculator converts these equations into a matrix. It solves Mx = 0 with exact fractions. Then it scales the answer to the smallest positive whole numbers.
Scaled moles: species moles = entered moles × species coefficient ÷ first reactant coefficient.
Scaled mass: mass = scaled moles × molar mass.
How To Use This Calculator
Enter the unbalanced reaction in the equation box. Use a plus sign between compounds. Use an arrow or equals sign between both sides.
Set the moles of the first reactant when you need scaled stoichiometric amounts. Choose decimal places for mole and mass values.
Turn the atom audit or mass plan on as needed. Press the submit button. The balanced result appears below the header and above the form.
Use the CSV button for spreadsheet work. Use the PDF button for a simple printable report.
About Chemical Reaction Balancing
A balanced chemical equation shows conservation of matter. Every atom that enters a reaction must appear in the products. The calculator uses that rule as its main test. It does not guess coefficients by trial only. It builds a table of each element in every compound.
Why Balance Matters
Balancing is needed before stoichiometry, yield work, and reagent planning. A wrong coefficient changes mole ratios. It can also change mass estimates. Students use balanced equations to check homework. Lab users use them to plan mixtures. The same idea supports cost studies when chemicals are purchased by amount.
How The Tool Thinks
The tool reads formulas on the left and right sides. It supports common element symbols, nested brackets, and hydrates. Then it creates one equation for each element. Hydrogen, oxygen, iron, chlorine, and every other element get their own row. The unknowns are the coefficients placed before each compound.
Advanced Result Checks
After solving, the calculator reduces the answer to the smallest whole numbers. It also shows an atom audit. This audit compares total atoms on both sides. Matching totals prove the equation is balanced. The mole table gives a scaled reaction plan. Enter moles for the first reactant to estimate matching amounts for every species.
Good Input Habits
Use normal formulas such as Fe2O3, Ca(OH)2, or CuSO4.5H2O. Put a plus sign between compounds. Put an arrow or equals sign between reactants and products. Spaces help when ions include charge signs. State labels such as aq or s may be ignored during balancing.
Helpful Use Cases
The calculator is useful for chemistry classes, process notes, and quick reports. It can export the result as CSV or PDF. The CSV file is easy to open in a spreadsheet. The PDF gives a simple record for sharing. Always confirm unusual reactions with trusted chemical data. Balancing checks atoms, not reaction feasibility, safety, or actual lab yield.
Limits To Remember
Some equations have many valid coefficient sets. The calculator selects the smallest positive integer set when possible. Redox reactions may also need charge balancing in special media. This page focuses on atom balance. It is best for standard formula equations and classroom style reaction checks during review.
FAQs
Can this calculator balance equations with parentheses?
Yes. It supports nested parentheses, square brackets, and braces. Examples include Ca(OH)2, Fe2(SO4)3, and K4[Fe(CN)6].
Can it handle hydrates?
Yes. Use a dot format such as CuSO4.5H2O. The parser multiplies the hydrate part and includes those atoms in the balance.
Does it check reaction safety?
No. It only checks atom conservation and stoichiometric ratios. It does not verify safety, feasibility, heat release, pressure, or required lab controls.
Why are coefficients whole numbers?
Chemical equations usually use the smallest whole number coefficients. The calculator solves fractions first, then converts them to the lowest positive integer ratio.
Can I enter existing coefficients?
Yes. Leading coefficients are removed before solving. The tool recalculates the smallest balanced set from the formulas you enter.
How are scaled moles calculated?
The first reactant is used as the base. Each species receives entered moles multiplied by its coefficient and divided by the first coefficient.
Why is molar mass unavailable sometimes?
Molar mass appears when all element symbols match the stored atomic weight table. Unknown or misspelled symbols can make mass unavailable.
Can I export the result?
Yes. Use CSV for spreadsheet work. Use PDF for a simple saved report with the balanced equation, coefficients, atom audit, and mole plan.