How to use this calculator
- Enter the reaction and one available quantity for every reactant.
- Enter the product formula that you want to calculate.
- Calculate and compare the normalized reaction extent for each reactant.
- Review the limiting reactant, excess remaining, and maximum product.
Formula and variables
reaction extent = nᵢ / nuᵢ
| Symbol | Meaning | Unit |
|---|---|---|
| nᵢ | species amount | mol |
| nuᵢ | balanced coefficient | dimensionless |
Worked example
For 2 H2 + O2 -> 2 H2O, H2=4 mol and O2=1 mol makes O2 limiting and permits 2 mol H2O.
Interpretation
The smallest available stoichiometric extent identifies the limiting reactant; remaining material is computed from that same extent.
Common mistakes
- Supply one quantity for every reactant using the displayed formula labels.
- Mass quantities require atomic data for every element in the formula.
Frequently asked questions
How does the calculator find the limiting reagent?
It divides each available mole amount by its balanced coefficient. The smallest result limits the reaction.
Can two reactants be limiting?
Yes. Two reactants tie when their available stoichiometric extents agree within the calculation tolerance.
Does the result include excess reagent?
Yes. The material-balance table shows the moles that remain after complete use of the limiting reagent.
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.