Societies and Academies

Abstract

LONDON Royal Society, March 9. J. H. AWBERY and E. GRIFFITHS: The heats of combustion of carbon monoxide in oxygen and of nitrous oxide in carbon monoxide at constant pressure. The heat of combustion of carbon monoxide in oxygen is 282,730 joules per mole at 20 ° C., correct to within 3 parts in 1,000. The heat of reaction when nitrous oxide burns in carbon monoxide is 364,340 joules per mole, correct to 2 or 3 parts in 1,000. From these two results, the heat of formation of nitrogen dioxide at constant atmospheric pressure and at a temperature of 20 ° C. is found to be 81,610 joules, that is, 19.50 cal.15 ° per mole. This quantity is determined as the difference between two heats of combustion, which were carried out with the same apparatus used in the same manner for both sets of experiments.—R. W. FENNING and F. T. COTTON: A bomb calori meter determination of the heats of formation of nitrous oxide and carbon dioxide. By means of a bomb calorimeter the heats of reaction of oxygen and nitrous oxide in carbon monoxide and hydrogen respectively were measured. Thus, by difference, two values were obtained for the heat of formation of nitrous oxide. A value for the heat of formation of carbon dioxide from carbon monoxide and oxygen was also obtained. Since the combustion of oxygen in hydrogen formed the calibration process, all the values given are based on the acceptance of 68,320 gm. cal.15 ° as the heat of formation of water (liquid) at constant pressure and at 25 ° C. On this basis, the heats of formation of nitrous oxide and carbon dioxide at a constant pressure of 1 atmosphere and at 20 ° C. were found to be—19.74 ± 0.07 kcal.15 °, or 82,600 ± 290 international joules, and 67.655 ± 0.035kcal.15 °, or 283,090 ± 150 international joules respectively. A. H. HUGHES and E. K. RIDEAL: On the rate of oxidation of monolayers of unsaturated fatty acids. The method of surface potentials has been employed to study chemical reactions occurring in a unimolecular film; the reactions examined being the oxidation by acidified potassium permanganate of long chain unsaturated aliphatic acids such as oleic acid. The reaction velocity depends on the accessibility of the double bond to the oxidising agent, and decreases markedly on compression of the film. Reaction velocity has been studied as influenced by the position of the double bond in relation to the polar carboxyl headgroup. Autoxidation in a unimolecular film has been observed for the elæostearic acids, and the effect of hydroquinone as an antioxygen to this reaction has been examined.