Molarity calculator (mol/L)
Calculate the molarity of a solution, the mass of solute to prepare a volume or the volume needed. Type the chemical formula and the molar mass is calculated for you.
Molarity, solute mass and volume
Fill in two of the three fields below and leave blank the one you want to find.
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Molarity calculator (mol/L): what it is for
Type the solute's formula to get the molar mass automatically or enter the value by hand. Fill in two of mass, volume and molarity and the tool calculates the third, plus the amount in moles and the mass concentration in g/L. It is the calculation used to prepare solutions in a volumetric flask.
The calculations run in your browser, with IUPAC standard atomic masses.
How to use
- Type the formula or the molar mass.
- Fill in two of the three fields.
- See the missing value and how much to weigh.
When to use it
- Prepare solutions in the lab.
- Solve concentration exercises.
- Convert g/L to mol/L.
Frequently asked questions
What is the molarity formula?
M = n / V, where n is the amount of solute in moles and V is the volume of the solution in liters. Since n = mass / molar mass, M = m / (MM × V) also works.
How do I prepare a solution of known concentration?
Choose the molarity and volume you want, leave the mass blank and the tool calculates how many grams to weigh. Dissolve it in part of the solvent and fill up to the final volume in a volumetric flask.
Is molarity the same as mass concentration?
No. Mass concentration is in g/L (grams of solute per liter). Molarity is in mol/L. To convert, multiply the molarity by the molar mass. The tool shows both.
Is it really free?
Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 tools are free and run right in your browser.