Molarity Calculator
Mass → moles → molarity, with error checks.
Enter the mass of the solute, its molar mass, and the solution volume to compute molarity in mol/L.
Steps: moles = mass ÷ molar mass, then M = moles ÷ volume (liters).
Result
--- mol/L
What is Molarity?
Molarity (M) is moles of solute per liter of solution (mol/L). It is handy for stoichiometry in solution because you can jump from volume to moles when you know M.
Quick calculation path: n = mass / molar mass, then M = n / V(L).
Lab notes (read before trusting a number)
- Use the final solution volume after dilution to the mark, not only the solvent you started with.
- Keep mL vs L consistent; convert once per problem.
- For hygroscopic solids or concentrated acids, prefer standardized solutions or fresh reagents when precision matters.
For workflow tips (dilutions, glassware habits, troubleshooting), see the Beta Calc guide on molarity—it complements this calculator without repeating the same worked example.
FAQs
- Why does my answer differ slightly from the bottle label?
- Labels report nominal concentration; temperature, density approximations, and activity effects can shift real concentration slightly—especially for strong acids/bases.
- Can I enter volume in milliliters?
- This tool expects liters in the volume field. Divide milliliters by 1000 before entering, or mentally scale your result.
- Is this medical or regulatory advice?
- No. Educational use only; verify independently for any safety, clinical, or compliance context.