Enter Reaction Data
Use consistent mass units throughout the calculation. Molecular weight should match the product identity and stoichiometry.
Sample reaction comparison
| Trial | Total Input (g) | Pure Product (g) | RME (%) | Yield (%) | PMI |
|---|---|---|---|---|---|
| Screening Run A | 152.00 | 69.20 | 45.53 | 72.60 | 2.197 |
| Pilot Run B | 165.00 | 94.50 | 57.27 | 82.10 | 1.746 |
| Optimized Run C | 149.00 | 103.40 | 69.40 | 88.70 | 1.441 |
This table shows how better yield control and lower excess input can raise reaction mass efficiency while lowering process mass intensity.
Formula used
Reaction mass efficiency measures how much of the chosen material input becomes the desired product. It is usually reported as a percentage.
Pure product mass = Actual isolated product mass × (Product purity ÷ 100)
Theoretical product moles = Limiting reactant moles × (Product coefficient ÷ Limiting reactant coefficient)
Theoretical product mass = Theoretical product moles × Product molecular weight
Reaction mass efficiency (%) = (Pure product mass ÷ Total selected input mass) × 100
Process mass intensity = Total selected input mass ÷ Pure product mass
Waste mass = Total selected input mass − Pure product mass
A higher reaction mass efficiency means more input material ends up in the desired product. A lower process mass intensity means less material is consumed per unit of product.
How to use this calculator
- Enter a batch label and choose one consistent mass unit.
- Type the isolated product mass and product purity.
- Enter product molecular weight and the limiting reactant moles.
- Add stoichiometric coefficients for the limiting reactant and product.
- Fill in each reactant mass. Leave unused fields at zero.
- Optionally include auxiliaries such as solvents or workup aids.
- Press Calculate Efficiency to show the result above the form.
- Review the chart, export the summary as CSV, or save a PDF report.
FAQs
1) What does reaction mass efficiency tell me?
It shows what percentage of your selected material input becomes the desired product. Higher values usually indicate lower waste, better material use, and greener synthesis performance.
2) Should solvents be included in RME?
Classical RME often focuses on reactants only. This calculator lets you include auxiliaries when you want a broader process view that reflects total material burden.
3) Why does the calculator adjust product mass by purity?
Impurities inflate isolated mass. Correcting for purity estimates the actual mass of desired product and gives a more realistic efficiency value.
4) What if my calculated yield exceeds 100%?
That usually means one or more inputs are inconsistent. Check molecular weight, stoichiometric coefficients, purity, unit conversions, and isolated mass measurements.
5) How is RME different from atom economy?
Atom economy is theoretical and based on reaction formulas. RME is practical and reflects actual masses, yield, and losses from the real process.
6) What is a good reaction mass efficiency?
There is no universal cutoff, but higher is better. In many settings, values above 60% are strong, while lower values often suggest improvement opportunities.
7) Why is process mass intensity included?
PMI complements RME. It tells you how many mass units of material are consumed to make one mass unit of product.
8) Can I use kilograms or milligrams instead of grams?
Yes. The calculator supports grams, kilograms, and milligrams. Keep every mass entry in the same unit for accurate results.