It is non-volatile in steam, and is odourless.
It is a non-volatile and almost infusible white powder, which slowly absorbs moisture and carbon dioxide from air, and is readily soluble in dilute acids.
The four phases are (I) crystals of salt, (2) crystals of ice, (3) a saturated solution of the salt in water, and (4) the vapour, which is that practically of water alone, since the salt is non-volatile at the temperature in question.
The vapour pressure of the solution of a non-volatile solute is less than the vapour pressure of the pure solvent.
The reasoning given above is independent of the temperature, so that the variation with temperature of the osmotic pressure of a dilute solution must be the same as that of a gas, while Boyle's law must equally apply to both systems. Experimental evidence confirms these results, and extends them to the cases of non-volatile solutes - as is, indeed, to be expected, since volatility is merely a matter of degree.
