Calculator Inputs
Plotly Graph
The chart compares ideal, adjusted theoretical, and actual target moles across the supplied known substance range.
Example Data Table
| Balanced equation | Known input | Target | Coefficient ratio | Theoretical target | Actual target at 90% yield |
|---|---|---|---|---|---|
| 2H₂ + O₂ → 2H₂O | 4 mol H₂ | H₂O | 2:2 | 4 mol, 72.06 g | 3.6 mol, 64.85 g |
| N₂ + 3H₂ → 2NH₃ | 6 mol H₂ | NH₃ | 3:2 | 4 mol, 68.14 g | 3.6 mol, 61.33 g |
| CaCO₃ → CaO + CO₂ | 100 g CaCO₃ | CaO | 1:1 | 0.999 mol, 56.02 g | 0.899 mol, 50.42 g |
| 2KClO₃ → 2KCl + 3O₂ | 245 g KClO₃ | O₂ | 2:3 | 3 mol, 96 g | 2.7 mol, 86.4 g |
Formula Used
1. Convert mass to moles
moles = mass ÷ molar mass
2. Stoichiometric mole ratio
target moles = known moles × (target coefficient ÷ known coefficient)
3. Adjust for sample quality and reaction progress
reacted known moles = supplied known moles × purity × completion
4. Theoretical target amount
theoretical target mass = theoretical target moles × target molar mass
5. Actual target amount
actual target moles = theoretical target moles × percent yield
6. Reverse requirement
required known moles = desired target moles × (known coefficient ÷ target coefficient), then divide by yield, completion, and purity factors.
Percent values are used as decimal factors inside calculations. For example, 90% becomes 0.90.
How to Use This Calculator
- Enter a reaction name and the balanced equation for reference.
- Select whether you know the supplied substance or the desired target output.
- Type the known and target substance names and their balanced coefficients.
- Enter the amount and choose moles or grams as the basis.
- Provide molar masses for both substances to unlock mass and mole conversions.
- Adjust purity, completion, and yield to match realistic laboratory conditions.
- Press Calculate Ratio to display the result above the form.
- Use the CSV and PDF buttons to save the calculated summary.
FAQs
1. What does this stoichiometry ratio calculator do?
It converts between known and target substances using balanced coefficients. It also handles grams, moles, purity, completion, yield, exports, and a reaction trend graph.
2. Why are balanced coefficients important?
Balanced coefficients define the mole relationship between substances. If the equation is unbalanced, every ratio, required amount, and predicted product value will be incorrect.
3. Can I enter grams instead of moles?
Yes. When you select grams, the calculator converts mass into moles using the molar mass. That makes the stoichiometric comparison possible.
4. What is the difference between completion and yield?
Completion describes how much of the available reactant actually reacts. Yield compares the real product obtained against the theoretical product predicted by stoichiometry.
5. Does the calculator find the limiting reactant?
No. This version uses one known substance and one target substance. For multi-reactant limiting analysis, you would need quantities for all reactants.
6. What is reverse stoichiometry mode?
Reverse mode starts with the desired target amount. It then estimates how much known substance must be supplied after considering purity, completion, and yield.
7. What does the graph show?
The graph compares ideal target moles, adjusted theoretical target moles, and actual target moles as the known substance increases. It helps visualize process losses.
8. When should I use purity below 100%?
Use a lower purity when the known substance contains impurities or dilution. The calculator reduces effective reacting moles before applying the stoichiometric ratio.