Calculator Form
Use purity to estimate the mass you should weigh. Use recovery to estimate the grams you may isolate after processing.
Plotly Graph
Formula Used
Core formula: grams = moles × molecular weight
Purity-adjusted mass: grams to weigh = theoretical grams ÷ (purity ÷ 100)
Expected recovered mass: expected recovered grams = theoretical grams × (recovery ÷ 100)
Molecules estimate: molecules = moles × 6.02214076 × 1023
These equations help you convert chemical amount into practical weighing mass while accounting for purity and anticipated process recovery.
How to Use This Calculator
- Enter the compound name for record keeping.
- Provide the molecular weight in grams per mole.
- Enter the required amount and choose mol, mmol, or µmol.
- Set purity if your reagent is not perfectly pure.
- Set expected recovery if you want an isolation estimate.
- Choose decimal precision and click Calculate grams.
- Review the result card, summary table, exports, and graph.
Example Data Table
| Compound | Molecular Weight (g/mol) | Amount | Purity | Theoretical Grams | Grams to Weigh |
|---|---|---|---|---|---|
| Water | 18.015 | 0.50 mol | 100% | 9.0075 g | 9.0075 g |
| Sodium Chloride | 58.44 | 2.50 mol | 98% | 146.1000 g | 149.0816 g |
| Glucose | 180.156 | 25 mmol | 99% | 4.5039 g | 4.5494 g |
| Acetic Acid | 60.052 | 150 mmol | 97% | 9.0078 g | 9.2864 g |
Frequently Asked Questions
1. What does this calculator convert?
It converts a chemical amount in moles, millimoles, or micromoles into grams using molecular weight. It also estimates the material you should weigh when purity is below 100%.
2. Is molecular weight the same as molar mass?
For routine chemistry calculations, they are used almost interchangeably. This calculator treats the entered molecular weight as grams per mole for direct mass conversion.
3. Why does purity increase the grams to weigh?
Lower purity means not all weighed material is the desired compound. The calculator divides the theoretical pure mass by the purity fraction, giving a higher weighing mass.
4. What is expected recovery used for?
Expected recovery estimates how many grams you may isolate after a process step. It does not change theoretical mass. It helps with planning experiments, scale-up, and material balances.
5. Can I use mmol instead of mol?
Yes. Choose mmol or µmol from the unit menu. The calculator converts that amount to moles automatically before applying the molecular weight formula.
6. Does the tool estimate molecule count?
Yes. It multiplies the calculated moles by Avogadro’s constant to estimate the number of molecules represented by the entered amount.
7. What if my result seems too large?
Check the entered unit carefully. Confusing mol with mmol is a common source of large errors. Also confirm the molecular weight and purity values before weighing reagents.
8. Can I use this for batch preparation?
Yes. The export options, graph, and purity adjustment make it useful for lab batches, pilot calculations, teaching examples, and documentation of reagent preparation steps.