The surface tension of water in various vapors were measured by the drop-volume method. As a result of the experiment, it was found that the “ Antonoff’s rule” holds good with some exceptions. In any vapors, a remarkable, but short ageing of water surface was found, which was 6 seconds in general, and which is prolonged by reduced pressure.
Separation of a small amount of titanium from iron with cation exchange resin was studied using alkali cyanide solution as eluting agent of iron. Successful results were obtained even in case of high iron concentration. This method enables us to remove the interfering effect of the iron on titanium colorimetry with hydrogen peroxide. As an examle of practical application, this method was tried in determining the titanium content of a limonite. The result agreed with that of the ordinary method of separation.
The changes of foaming porwer of the solution of congo red by the addition of electrolytes have been estimated. There is a prominent maximum in the foam duration by the change of the concentration of electrolyte, while no such maximum is seen in the foaminess. The electrolyte concentrations, at which the foam strength becomes maximum, and the coagulation value changes in the same trend from an electrolyte to the other. This is accounted for the fact that the affinity of polar part of dye ion to solvent is weakened by the addition of electrolyte.
The energy levels of cycloöctatetraene as D2d and D4d were calculated by the H-L-S-P method. Then we showed that the ground state of C8H8 (D2d and D4d) may be diamagnetic. The resonance energy of C8H8 (D2d and D4d) is about several kilocalories (about ten per cent of that of benzene) from thermochemical data and numerical calculation. The wave length of absorption spectra calculated assuming D2d is in better agreement with the experimental result than that calculated assuming D4d.
Viscosities of the dilute solutions of polyvinyl acetate have been measured in acetone-water mixtures of varying proportions. The experimental results are well expressed by the following equation η_sp/c=[η]+k[η]^2c. The intrinsic viscosity ([η]) shows a slight maximum at about 5% of water content, and decreases gradually for larger content of water. The value of k is close upon 0.4 and does not vary appreciably.
As the most sensitive method for the determination of uranium, the fluorescence method is recommended. Fluorescent material of sodium fluoride containing a small amount of uranium (10−4 to 109g. per 20 mg. of sodium fluoride) was investigated in this paper from several sides. Relation between fluorescence intensity and uranium content is described, and the fluorescence band spectrum was studied by speetrophotometry, regarding its spectral energy distribution. Various interfering factors to this method were examined too, especially as to its analytical application.
1) The catalytic hydrogenation of acetylene was investigated by Pd-Alumina under various conditions. 2) The hydrogenation of acetylene proceeds in two distinct steps. The first step consists of the reduction and polymerization of acetylene, and the second step the reduction of ethylene to ethane. The second reaction starts after all of the acetylene is reduced to ethylene, and is indicated by a sudden increase in the rate of hydrogenation. 3) The results indicate that acetylene is strongly adsorbed on the surface of the catalyst and the inhibition of the hydrogenation by acetylene is pronounced. 4) It was found that the final products of the hydrogenation can be made wholly into ethylene or ethane and that the highest yield of ethylene is obtained possibly, when acetylene content is small, by avoiding the polymerization of acetylene.
On the uranium hexafluoride obtained by the reaction between fluorine and uranium carbide, the viscosity was measured between 14.5° and 44.7°. The purification of uranium hexafluoride was performed by several repeated sublimation. The oscillating-disk viscosimeter was used in this experiments and its apparatus constant was obtained by the observation of the apparatus filled with air. The molecular diameter of uranium hexafluoride was determined from the Sutherland’s constant, and the rigidity of the molecule was also obtained from the observed values.