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Free Molarity Calculator

Calculate the molarity of a solution from the mass of solute, its molar mass, and the solution volume.

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Molarity measures how concentrated a solution is, in moles of solute per liter of solution.

This calculator finds the molarity of a solution from the mass of solute dissolved, its molar mass, and the total solution volume.

How it works

Enter the mass of solute in grams, its molar mass in g/mol, and the volume of the solution in liters. The calculator first finds the number of moles \(n = m/M\), then divides by volume to get molarity \(M = n/V\).

  1. Enter mass of solute (g).
  2. Enter molar mass (g/mol).
  3. Enter volume of solution (L).
  4. Click Calculate to see your results.

Examples

58.44 g of table salt in 1 L

Dissolving 58.44 g of sodium chloride (molar mass 58.44 g/mol) in enough water to make 1 L of solution produces exactly a 1 mol/L (1 M) solution.

Who should use it

  • Preparing a solution of known concentration for a chemistry lab.
  • Checking coursework involving molarity, moles, and solution concentration.

Industry applications

  • Chemistry education and laboratory work
  • Pharmaceutical and industrial chemical formulation

Advantages

  • Computes both moles and molarity in a single calculation.
  • Works for any solute and solvent combination.

Limitations

  • Doesn't account for volume changes on mixing (relevant for very concentrated solutions).

Common mistakes to avoid

  • Using the volume of solvent added instead of the final total solution volume.
  • Entering the molecular formula's weight in the wrong units (this calculator expects g/mol, not kg/mol).

Best practices

  • When preparing a solution in the lab, use a volumetric flask so the final volume is precisely known.

Tips

  • Pair this with the Molecular Weight Calculator to go straight from a chemical formula to a target molarity without looking up molar masses manually.

Frequently asked questions

Yes, with no signup and no limit on how many calculations you run.
You can look it up on a reference table, or use this site's Molecular Weight Calculator, which computes it directly from a chemical formula.
Molarity is moles of solute per liter of solution (volume-based), while molality is moles of solute per kilogram of solvent (mass-based) — this calculator computes molarity.
It's the volume of the final solution after the solute is dissolved, not just the solvent used to make it — these can differ slightly.

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