Inputs
Pure mass
—
g
Computed as
moles × molar mass after unit handling.Weigh mass (purity-adjusted)
—
g
Weigh this amount if material purity is below 100%.
Formula used
Pure grams: n × M, where n is amount in moles and M is molar mass (g/mol).
Unit handling: if input is in mmol, then n = mmol / 1000. Output can be shown in mg, g, kg, or lb.
Purity correction: to weigh impure material and still obtain the required pure grams, use weigh = pure / (purity/100).
Example: 0.25 mol NaCl, M = 58.44 g/mol → 14.61 g pure.
How to use
- Enter amount and choose mol or mmol.
- Provide molar mass, or click From formula and type a formula.
- Pick output unit (mg, g, kg, or lb) and optional purity.
- Click Compute for results. Use Add to table to log runs.
- Export your table as CSV or PDF for your records.
Runs table
Example rows included for reference.
| # | Timestamp | Amount | Molar mass (g/mol) | Purity (%) | Pure mass | Weigh mass | Notes |
|---|---|---|---|---|---|---|---|
| 1 | 2025-11-05 09:00 | 0.25 mol | 58.44 | 100 | 14.61 g | 14.61 g | NaCl |
| 2 | 2025-11-05 09:02 | 0.05 mol | 180.156 | 100 | 9.0078 g | 9.0078 g | Glucose |
| 3 | 2025-11-05 09:05 | 2.5 mmol | 98.079 | 100 | 0.2452 g | 0.2452 g | H2SO4 |
Common molar masses (selected reagents)
| Substance | Formula | Molar mass (g/mol) | Notes |
|---|---|---|---|
| Water | H2O | 18.01528 | Deionized basis |
| Sodium chloride | NaCl | 58.44 | Analytical grade |
| Glucose | C6H12O6 | 180.156 | D‑glucose |
| Sulfuric acid | H2SO4 | 98.079 | Anhydrous |
| Hydrochloric acid | HCl | 36.46094 | Gas basis |
| Calcium carbonate | CaCO3 | 100.0869 | Calcite/aragonite |
| Sodium hydroxide | NaOH | 39.997 | Palletized/flake |
| Potassium chloride | KCl | 74.5513 | Reagent grade |
| Copper(II) sulfate pentahydrate | CuSO4·5H2O | 249.685 | Hydrate |
| Ammonia | NH3 | 17.0305 | Gas basis |
Unit conversion cheat sheet
| Relationship | Factor |
|---|---|
| 1 mol = 1000 mmol | ×1000 (mmol) or ÷1000 (mol) |
| 1 g = 1000 mg | ×1000 (mg) or ÷1000 (g) |
| 1 kg = 1000 g | ×1000 (g) or ÷1000 (kg) |
| 1 lb = 453.59237 g | ×453.59237 (g) or ÷453.59237 (lb) |
Worked examples (moles → grams)
| # | Amount | Formula | M (g/mol) | Pure mass (g) | Pure mass (mg) | Pure mass (lb) | Weigh at 95% (g) |
|---|---|---|---|---|---|---|---|
| 1 | 0.25 mol | NaCl | 58.44 | 14.6100 | 14610.0000 | 0.03221 | 15.3789 |
| 2 | 2.5 mmol | H2SO4 | 98.079 | 0.24520 | 245.1975 | 0.00054 | 0.25810 |
| 3 | 0.05 mol | C6H12O6 | 180.156 | 9.0078 | 9007.8000 | 0.01986 | 9.4819 |
Notes
- Molar masses are averages for naturally occurring isotopic abundances.
- Computed values are rounded to the selected number of decimals.
- Always confirm critical calculations for regulated or safety-sensitive work.