Molarity Calculator
Calculate the molarity (concentration) of a solution, the number of moles of solute, or the volume of solution needed. Uses the fundamental formula M = n / V where M is molarity in mol/L, n is moles of solute, and V is volume in liters.
Molarity is the most common way to express the concentration of a solution in chemistry. It is defined as the number of moles of solute dissolved per liter of solution.
The Formula: M = n / V
- M = Molarity (mol/L or M)
- n = moles of solute (mol)
- V = volume of solution (L)
Rearranged Forms
- Solve for moles: n = M × V
- Solve for volume: V = n / M
Example
If you dissolve 0.5 moles of NaCl in 2 liters of water, the molarity is: M = 0.5 / 2 = 0.25 M (0.25 molar)
Important Notes
- Volume refers to the total volume of the solution, not just the solvent
- Molarity changes with temperature because liquid volumes expand and contract
- For temperature-independent concentration, use molality (moles per kg of solvent)