[dangerdoc]

Osmolarity is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per liter (L) of solution (osmol/L or Osm/L).

Osmolality is a measure of the osmoles of solute per kilogram of solvent (osmol/kg or Osm/kg).

[decimon]

Osmolarity is the measure of solute concentration, defined as the number of osmoles (Osm) of solute per liter (L) of solution (osmol/L or Osm/L).

Osmolality is a measure of the osmoles of solute per kilogram of solvent (osmol/kg or Osm/kg).

This is all part of the conspiracy to make me feel stupid. ;-)