Calculate molarity

Calculate molarity or solve the mass, moles, molar mass, or final solution volume needed for it.

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ToolMolarity Calculator
Input
Output
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How it works

Moles are mass divided by molar mass, and molarity is moles divided by litres of final solution. The same relationship is rearranged when concentration or volume is unknown.

  • Final solution volume is required.
  • Molar mass is an explicit solute input.

Worked example

Concentration of a salt solution
5.844g of NaCl dissolved to make 0.5L, concentration left blank to be solved
Input
											Molar mass gmol: 58.44
Mass grams: 5.844
Volume litres: 0.5
Output
												Moles: 0.1
Mass grams: 5.844
Volume litres: 0.5
Concentration molar: 0.2
Molar mass gmol: 58.44

When to use this

Labs prepare sodium chloride solutions, titration worksheets convert weighed solute, and teaching experiments solve required mass.

Edge cases

  • One litre of solvent is not necessarily one litre of final solution.
  • Millilitres must become litres before division.
  • Non-positive molar mass or volume cannot produce a physical concentration.

References