The temperature variation of orthobaric density difference in liquid-vapour systems. II. Water and deuterium oxide

The density of deuterium oxide has been determined over the range 20-200° by means of a sealed- dilatometer. The densities above the boiling point are found to be higher than those reported by previous workers. The applicability of the Verschaffelt equation to ascociated systems of the water type has been examined, and it is shown that the exponent has different values for ranges of temperature below and above the boiling point, and is substantially lower than that found for a normal liquid.