III. The thermal properties of carbonic acid low temperatures

• Published in: Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1914
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1098/rsta.1914.0003; https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1914.0003

The experiments described in the following paper were originally undertaken to determine the Latent Heat of Liquid CO 2 and the Specific Heats of the liquid and of the gas at temperatures below —30°C., which is the lowest temperature for which Mollier has calculated them, and also to check Mollier's Entropy-Temperature diagram by direct experiment, as it appeared likely that the calculated results might be appreciably wrong near the limits of their range. The results of the first experiments confirmed this expectation, and it became apparent at the same time that Mollier’s θ ϕ diagram could not be modified to agree with the experimental results without some further data. The investigation was therefore extended so as to include the measurement of all the quantities required for the construction de novo of a θ ϕ diagram for saturated gas at low temperatures. Finally, by Sir Alfred Ewing’s suggestion, the range of the experiments was further extended to higher temperatures, to enable the diagram to be constructed nearly to the critical point. The experiments made to carry out this programme were:— 1. The determination of the Pressure-Temperature Curve for Saturated Vapour; 2. Three series of heat measurements, called Series I., II., and III., to determine the Latent Heat L, the Total Heat I of the liquid, and the Specific Heat of the gas.