Molarity to Molality Converter
Convert solution molarity and solvent-based molality using entered solution density and solute molar mass.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Express final solution density in kilograms per liter. Relate solute moles to solute mass using molar mass. Separate solvent mass from total solution mass. Convert between moles per liter and moles per kilogram of solvent.
m=1000M/(1000ρ−M×molar mass); M=1000ρm/(1000+m×molar mass)
Worked example
At density 1.05844 kg/L and solute molar mass 58.44 g/mol, molarity 1 mol/L corresponds to molality 1 mol/kg.
Assumptions and input details
One solute and a positive remaining solvent mass are required. Density describes the final solution at the scenario temperature. No volume additivity, density lookup, reaction or dissociation model is assumed.
References: OpenStax: colligative properties
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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