It was shown recently based on the idea of partial dissociation of strong electrolytes, that the "molal volume" of NaCl(aq) is the sum of the "volumes" of ions. ion pairs, solvent, and electrostriction. Here it is demonstrated that the large amount of density data available in the literature conforms with this interpretation. For comparison, the densities calculated on the assumption of complete dissociation are provided. Also, the equation far the dissociation "constant" is shown to involve the volumes of ions and ion pairs.