Volume 11, Issue 3, 01 March 1943
Index of content:
11(1943); http://dx.doi.org/10.1063/1.1723810View Description Hide Description
The fundamental frequencies, anharmonicities, and vibrational modes for the molecules HDO, HTO, DTO, and T2O are calculated on the basis of Dennison's and Darling's recent analysis of the vibrational spectrum of the H2O molecule. The equilibrium constants for nine equilibria involving these molecules are given. Experimental values for the reactions HD+H2O=H2+HDO and HT+H2O=H2+HTO are compared with those calculated. It is concluded that the vibrational potential function is essentially unaltered by isotopic substitution.
11(1943); http://dx.doi.org/10.1063/1.1723811View Description Hide Description
A diffusion method of investigating surface recombination of atoms by substances of low catalytic power is presented. By this method we have evaluated the coefficient of recombination γ for H and OH on Pyrex for a temperature range of over 500°C. For smaller ranges of temperature we have found the recombination of H on a number of salts, and have found this recombination to be strongly dependent on the dryness of the surface. All salts investigated save KCl strongly recombined H when dry. Salts recombining H could not be investigated for OH recombination. However KCl, which did not recombine H, did recombine OH strongly. A number of strong dehydrogenating and dehydrating agents were tested for differences in H and OH recombination, but no difference was found.
11(1943); http://dx.doi.org/10.1063/1.1723812View Description Hide Description
A molecular model in terms of which the elasticviscousproperties of rubber‐like substances can be interpreted is presented. Experiments on stress relaxation at constant extension, creep under constant load, extrusion, vibration, and breaking are discussed in terms of a mathematical formulation of this molecular model.
11(1943); http://dx.doi.org/10.1063/1.1723813View Description Hide Description
The rate at which gases from the atmosphere diffuse through monel metal at various temperatures has been observed. An evacuated heavy‐walled metal tube, a section of which was machined to a thin wall, was heated in a furnace. The rate at which the pressure inside the tube increased as a result of the diffusion of gases from the atmosphere was noted. The log R vs. 1/T curves, which are usually linear, show breaks about 900°C indicating some unusual physical change occurring in the alloy at this temperature. Dilatometric measurements on the same alloy were used to check the location of this break.
11(1943); http://dx.doi.org/10.1063/1.1723814View Description Hide Description
It is shown that certain Coriolis interaction terms in the rotation‐vibration Hamiltonian of a linear polyatomic molecule give second‐order contributions to the energy which remove the degeneracy of levels associated with the quantum number l of internal angular momentum arising from a doubly degenerate perpendicular mode of oscillation. This type of splitting is called ``l‐type doubling'' because it is exactly like ``Λ‐type doubling'' in the electronic energy levels of diatomic molecules.
11(1943); http://dx.doi.org/10.1063/1.1723815View Description Hide Description
The crystal structure of gadolinium formate has been studied by means of Laue, rotation, and powder x‐ray patterns. It has a rhombohedral lattice. The unit cell, a 0=6.17A, a=115° 30′, contains one molecule, Gd(OOCH)3. Density—(calculated) 3.85, (Berman balance) 3.77. By taking into consideration the symmetry of special positions all space groups except D 3 7—R32 and C 3v 5—R3m can be excluded. A structure has been found in the latter group which yields excellent agreement of calculated and observed intensities.
11(1943); http://dx.doi.org/10.1063/1.1723816View Description Hide Description
The rates of saponification of ethyl benzoate, ethyl toluate, ethyl anisate, ethyl p‐chlorobenzoate, and ethyl p‐nitrobenzoate have been measured in several alcohol‐water mixtures. The relative rates of saponification of the substituted benzoic esters have been compared with those computed by the Kirkwood‐Westheimer theory.