mmol/kg

millimole per kilogram

Molalityexact by definition

The millimole per kilogram is one thousandth of a molal: millimoles of solute per kilogram of SOLVENT, not of solution. The factor of 0.001 is exact, being a decimal prefix. It is the working unit for dilute solutions in physical chemistry and for oceanographic and geochemical reporting, where a temperature-independent concentration matters.

1 mmol/kg 0.001 mol/kg