Stoichiometry Equation Calculator
Example Data Table
| Reaction | Known | Target | Known Amount | Mole Ratio | Theoretical Product |
|---|---|---|---|---|---|
| 2H2 + O2 -> 2H2O | 32 g O2 | H2O | 1.000 mol O2 | 2:1 | 36.03 g H2O |
| N2 + 3H2 -> 2NH3 | 28 g N2 | NH3 | 1.000 mol N2 | 2:1 | 34.06 g NH3 |
| CaCO3 -> CaO + CO2 | 100 g CaCO3 | CO2 | 0.999 mol CaCO3 | 1:1 | 43.98 g CO2 |
Formula Used
The calculator converts the known quantity into moles first. Then it applies the balanced mole ratio to estimate the target amount.
usable source moles = entered moles x (purity / 100)
target moles = usable source moles x (target coefficient / source coefficient)
target mass = target moles x target molar mass
actual yield = theoretical mass x (percent yield / 100)
For gases at standard temperature and pressure, the tool uses 22.4 liters per mole. Particle counts use Avogadro's constant, 6.02214076 x 10^23.
How to Use This Calculator
- Write the balanced chemical equation in the reaction field.
- Choose the known compound and the target compound.
- Enter both stoichiometric coefficients from the balanced equation.
- Type the measured amount and select the proper unit.
- Provide molar masses for both compounds.
- Add sample purity and expected percent yield if needed.
- Submit the form to display the result summary above it.
- Download the result table as CSV or PDF for records.
Frequently Asked Questions
1. What does this stoichiometry calculator solve?
It converts a known reactant or product amount into moles, applies the balanced ratio, and estimates target moles, mass, gas volume, particles, and yield.
2. Do I need a balanced equation first?
Yes. Stoichiometric coefficients come from a balanced equation. If the equation is not balanced, the ratio and every downstream result will be incorrect.
3. Can I enter grams instead of moles?
Yes. The calculator accepts moles, grams, kilograms, particles, and gas volume at STP. It converts the chosen input into moles before solving.
4. Why does purity change the answer?
Impure samples contain less active substance than the label mass suggests. The tool reduces usable moles by the purity percentage before applying ratios.
5. What is percent yield used for?
Percent yield compares actual production with the theoretical maximum. Entering it lets the calculator estimate practical mass instead of only ideal output.
6. When should I use the gas volume option?
Use it when the known quantity is a gas measured at standard temperature and pressure. The tool assumes 22.4 liters per mole.
7. Does this replace a limiting reagent calculation?
No. This version converts one known substance into one target substance. For multiple reactants, determine the limiting reagent before using the result.