Molality vs. Osmolality — What's the Difference?

Molality is a measure of the number of moles of solute in a solution corresponding to 1 kg or 1000 g of solvent. This contrasts with the definition of molarity which is based on a specified volume of solution.

(chemistry) The molality of an ideal solution that would exert the same osmotic pressure as the solution being considered.

Abbr. m The concentration of a solution expressed in moles of solute per kilogram of solvent. Also called molal.

(chemistry) the concentration of a substance in solution, expressed as the number of moles of solute per kilogram of solvent

A measure of concentaration of substances in mixtures, 1 molal being the concentration of a solution containing 1 mole of solute per 1000 grams of solvent. Compare molar.

Molal concentration