Use the reagent calculator
Find a molar mass from a formula or reagent name and do solution, dilution and mole calculations next to your note.
Applies to Web · Mac · iPhone app · anyone who can view the note
The reagent calculator handles the three calculations you do every day at the bench: “how many grams for 100 mL of 0.5 M?”, “how much stock do I take (C1V1 = C2V2)?” and “how many moles is the 2.5 g I weighed?”. Results aren’t inserted into the note automatically, so copy over the values you need.
Open the calculator
- Click ⋯ (Note tools) in the note header.
- Under Records, choose Reagent calculator.
If the note contains formulas shown with subscripts, they appear as chips at the top of the calculator (up to 12), and the first one is loaded for you. Click a chip to switch to that formula.
Look up a molar mass
Type a formula or a name in the search field and press Enter.
| You type | How it’s found | Shown as |
|---|---|---|
A formula (H2SO4, CuSO4·5H2O) | Calculated on the spot by adding atomic masses. No internet connection needed. | Computed from the formula |
A name, abbreviation or CAS number (sulfuric acid, EtOH, 황산) | The server looks it up on PubChem. Common Korean reagent names and lab abbreviations are translated to English names first. | Fetched from PubChem |
| A name that has been looked up before | The value saved on the server is used right away. | Saved earlier |
For reagents found on PubChem, the formula, CAS number and density (when available) are shown with the molar mass. Write hydrates with · or * between the parts.
Calculate
| Section | What you enter | Result |
|---|---|---|
| Solution to make | Concentration (M) and volume (mL or L) | Grams to weigh. For liquids with a known density, the volume in mL too. |
| Dilute from stock | The Stock concentration (M). The target concentration and volume come from the section above. | How many mL of stock to take, then make up to the volume above. |
| Moles in a weighed amount | Mass (g) | mol |
Good to know
- If the target concentration is higher than the stock, you’ll see Cannot make it more concentrated than the stock.
- Volumes converted from density don’t account for purity. Check the assay on the bottle separately.
- Name lookups go through the server, so offline you can only calculate from formulas.
- Formulas that aren’t shown with subscripts in the text, such as
C60, still work when typed into the calculator. See Chemical subscripts and exceptions.