(1) For studying the liquid-and vaporphase equilibrium of the CO2-NH3-Urea-H2O system under high temperature and pressure, details of methods to determine mole ratios of ammonia, carbon dioixde and water in the vapor phase, mole ratio of ammonia to carbon dioxide in the liquid phase, and volume-ratio of the vapor-to liquid-phase in an autoclave have been described. (2) Experimental results at temperatures between 140 and 180°C. and over the loading density range of 0.20 to 1.00 g./cc. have been shown in the case of the loading mole ratio of 2NH3 to 1 CO2. (3) The relations among the equilibrium yield of urea, the loading density and the temperature were discussed from the standpoint of the liquid- and vapor-phase equilibrium. (4) The liquid- and vapor-phase compositions in the equilibrium state of the system have been calculated on an assumption that the system consists of three components, ammonia, carbon dioxide and water, in the vapor phase and of four components, urea, water, ammonia and carbon dioxide, in the liquid phase. (5) The equilibrium constant of the following reaction represented by mole fraction of each component in the liquid phase is approximately constant independent of the loading density at a given temperature. CO_2+2NH_3\
ightleftarrowsCO(NH_2)_2+H_2O (6) A discontinuous point appearing in a plot of the equilibrium constant against the temperature at a given loading density has been discussed. (7) The liquid- and vapor-densities of the system under high temperature and pressure have been calculated from the equilibrium compositions.
1. Quantitative precipitation of strontium as its oxalate monohydrate is made possible by employing 50% alcohol as the washing solution and by drying the precipitate at 100–105°C for 2 hrs., and as a consequence a new method for determining strontium gravimetrically was established. 2. It was found that strontium can be determined volumetrically by titrating with potassium permangante the oxalic acid which is formed when the strontium oxalate prepared by the above method is decomposed with sulfuric acid.
By use of heavy oxygen as an isotopic tracer, the following facts have been found; 1. At the catalytic decomposition of potassium chlorate in the presence of manganese dioxide, an unstable compound is formed between potassium chlorate and manganese dioxide, and oxygen gas is liberated by the decomposition of this intermediate compound. 2. The active part of manganese dioxide capable of composing such an intermediate compound with potassium chlorate is only a limited small portion of the particle. 3. Such an active part is readily destroyed by such a severe treatment as the heating of the catalyst in a vacuum at high temperature.
Absorption spectra of m-nitronitrosobenzene monomer in crystalline state as well as in solution have been measured quantitatively in the visible and the ultraviolet regions. In its π-band of the ultraviolet region, the general rule about the π-band of the benzene ring was found to hold also for the present case. In regard to the nitroso band of the visible region, the absorption by linearly polarized light with the electric vector vibrating perpendicular to the C–N–O bond was hyperchromic to the absorption by the light with those vibrating parallel to it. This result suggests that the green colour of m-nitronitrosobenzene is due to the electronic transition polarized perpendicularly to the C–N–O bond.
(i) Several derivatives of Δ2-selenazolines were synthesized from N-acylethanolamine and phosphorus pentaselenide. The larger the alkyl group was, the better the yield became. (ii) 2-Arylselenazolines were solid and did not give picrates, differing from 2-alkylselenazolines.