Molarity
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Molarity and Molality Calculator
Calculate molarity, molality, or density-based conversions with explicit solution and solvent denominators.
At a glance
- Computes
- Molarity, molality, and density conversions, with each denominator named.
- You supply
- Solute amount or mass, plus solution volume or solvent mass, and density.
- Use when
- You must be explicit about whether the denominator is solution volume or solvent mass.
- Not for
- Diluting a stock to a target concentration. Dilution Calculator
Molality
Enter values
| Item | Value |
|---|
M = n / L solution; molality = n / kg solvent
How?
How this is calculated
Molarity divides moles of solute by liters of total solution. Molality divides moles of solute by kilograms of solvent. Density conversions use a one-solute model and require both solution density and solute molar mass.
Formula: M = n / L solution; molality = n / kg solvent
Molarity vs molality
Both describe solute amount, but their denominators differ. Molarity divides moles by litres of the whole solution. Molality divides moles by kilograms of solvent alone. Solution volume changes with temperature while mass does not, so molality is preferred for colligative properties and molarity is natural for volumetric laboratory work. Converting between them needs solution density and solute molar mass because the conversion must separate the solvent mass from the solution volume.
Normality
Normality is molarity multiplied by equivalents per mole. A 0.500 M sulfuric acid solution is 1.000 N when two replaceable protons count; 0.100 M sodium hydroxide is 0.100 N when one hydroxide counts. Equivalent weight is molar mass divided by the same reaction-specific number. The tool never infers that number from a formula because one species can transfer a different number of equivalents in acid-base and redox reactions.
IUPAC deprecates normality because its value depends on the reaction, but the unit remains in titration and water-treatment practice. This page keeps the equivalents count visible beside the result. For the next laboratory step, use the dilution calculator to solve the volume change.
Sources
- IUPAC Gold Book, amount concentration. IUPAC. Retrieved .
- IUPAC Gold Book, molality. IUPAC. Retrieved .
- OpenStax Chemistry 2e, Molarity. OpenStax. Retrieved .
- OpenStax Chemistry 2e, Other Units for Solution Concentrations. OpenStax. Retrieved .
Method last reviewed