Molarity Calculator
Calculate molarity (mol/L) from moles and volume, or required moles/grams for a target solution.
What is Molarity Calculator?
The molarity calculator computes M = n/V where M is molarity (mol/L), n is moles, and V is volume in liters.
Formula
M = n / V. To find required mass: mass = moles × molar mass.
Worked example
0.5 mol NaCl in 2 L water: M = 0.5/2 = 0.25 mol/L = 0.25 M. Mass: 0.5 × 58.44 = 29.22 g.
How to use this calculator
- Enter moles and volume.
- Optionally add molar mass for required mass calculation.
- Molarity in mol/L appears.
Frequently asked questions
What's a mole?
A mole is 6.022 × 10²³ particles (Avogadro's number). It's a unit for counting molecules. The molar mass is the mass in grams of one mole of a substance.
Common molar masses?
Water (H₂O): 18.02 g/mol. NaCl: 58.44 g/mol. Glucose: 180.16 g/mol. Sodium hydroxide (NaOH): 40 g/mol. Look up specific compounds in periodic table tools.
How do I make a 1 M solution?
Weigh out 1 mole of solute (using molar mass), dissolve in some water, add water to a 1 L total volume. Use a volumetric flask for precision.
Molarity vs molality?
Molarity is moles per liter of solution. Molality is moles per kg of solvent. Molality is independent of temperature; molarity changes with temperature (since liquid volume varies).