bluuebunny/crossref_metadata_2025 huggingface dataset:
The Kinetics of the Thermal Decomposition of Methyl Ethyl Ether
Authors: Steacie E. W. R.
Published: November 2004

The kinetics of the decomposition of methyl ethyl ether have been reinvestigated. The results obtained differ considerably from those of Glass and Hinshelwood. The heat of activation is found to be 54,500±1500 calories. This value brings the activation energy of methyl ethyl ether into line with those of the other ethers.
Analysis of Rotatory Dispersion Curves of Configurationally Related Fatty Acids
Authors: Levene P. A. , Rothen Alexandre , Marker R. E.
Published: November 2004

The dispersion curves of fatty acids of the type     CH3     |H–C–(CH2)xCOOH     |    Rhave been measured in the visible and in the ultraviolet regions with a view to establishing the sign and the magnitude of the contribution of the radicals     CH3     |H–C–(CH2)x−     |    Rand —COOH to the total rotation. The variables were R and x, the latter varying from 0 to 2. It was found that the increase of the chain of R had no effect on the sign of the contributions. The change of x from 0 to 1 or 2 resulted in a change of sign of the contribution of —COOH, leaving the sign of the other contribution unchanged. For 4 of the compounds it was possible to determine with precision the values of each of the two contributions.
The Influence of Foreign Gases on the Intensity of Infrared Absorption
Authors: Cross Paul C. , Daniels Farrington
Published: November 2004

Measurements have been made on the effect of helium, argon, oxygen, nitrogen, ethane, carbon dioxide and hydrogen on the maximum absorption by nitrous oxide in the region of 4.5μ, by using a spectrometer of low resolving power. Some measurements have also been made with carbon monoxide and ethyl bromide as the absorbing gases. Relative ``optical'' collision diameters, calculated on the postulate that the mean free paths are equal in gas mixtures having the same relative absorption coefficients, show a linear relationship with the gas-kinetic diameters as determined by viscosity measurements. The applicability of Beer's law is discussed in connection with the use of infrared absorption measurements as a means of analysis.
The Significance of Chemical Bond Energies
Authors: Zahn C. T.
Published: November 2004

In view of recently reported departures from bond additivity of chemical energies of formation, a purely empirical study has been made of the significance of chemical bond energies. If one assumes that the energy of formation is made up of bond energies and interaction energies between the bonds as well, it is shown that both of these two types of energy are indeterminate so far as thermochemical data are concerned. Under certain simple conditions on the interaction energies apparent bond additivity would obtain and one could then define apparent bond energies. In case these additivity conditions are not valid, it is further shown how the energy of formation can be expressed in terms of the apparent bond energies with a correction term involving the numerical departures from the additivity conditions. It is also shown that under a transformation of reference state to excited states of the atoms: (1) the additivity characteristics are invariant, and (2) the bond resonance energies as defined by Pauling are invariant, and therefore the reference of bond energies to excited states has no significance so far as these resonance energies are concerned. A discussion of atomic and bond additivity is given for physical quantities in general. It is pointed out that the energy connected with the nuclear motions, that is the heat content plus the zero-point energies of the vibrations, may be of the order of one-tenth the total energy of formation. Since this latter energy would not be expected on the whole to exhibit bond regularities, it is therefore proposed that ``electronic'' energies be introduced for the study of structural regularities in the energies of formation. A study is then made of available data in terms of the proposed scheme. Because of the lack of accurate data it is at present not possible to make a very thorough test. But a certain amount of information is obtained from the excellent data of Rossini on some of the CHO compounds, and so far as reliable data are available reasonable results are obtained, which indicate that in some cases the departures from additivity may be considerably greater than ordinarily supposed. It is further pointed out that Pauling's bond resonance energies could not accurately be considered as pure bond quantities if the interactions were appreciable, and that this may be the reason in part, that his electro-negativity map cannot on the whole be used successfully to predict the electric moments of chemical bonds.
A Kinetic Expression for the Rate of the Photosensitized Decomposition of Ammonia and Deuteroammonia
Authors: Evans Meredith G. , Taylor Hugh S.
Published: November 2004

A kinetic expression for mercury sensitized ammonia and deuteroammonia decompositions which represents the experimental data is developed empirically and an explanation of the expression in terms of the various kinetic processes is sought. This expression is further modified to include the intrinsic decomposition probability of the ammonia or deuteroammonia molecule. The final expression is able to express the results quantitatively, and yields values for the quenching ratio, k1NH3 : k1ND3 = 4 : 1 and a decomposition probability after quenching k1NH3 : k1ND3 = 5 : 1.
The Photochemical Oxidation of Phosphine above the Upper Explosion Limit
Authors: Melville H. W. , Roxburgh H. L.
Published: November 2004

An investigation has been made of the kinetics of the photochemical oxidation of phosphine above the upper explosion limit. The results are summarized by the equations

Mercury sensitized reaction — d[PH3]/dt = const. [PH3]/[O2]2 intensity.

Direct photo-reaction — d[PH3]/dt = const. [PH3]2/[O2]2.

The reactions are shown to be of the chain type and inhibited by oxygen. On the basis of previous knowledge of the propagation of the chains, the question of termination was examined and it is shown that out of six possible cases, only one is in agreement with the experimental facts. This is that the chain carrier, which normally reacts with phosphine, is destroyed in a ternary collision with two oxygen molecules or with one oxygen and one nitrogen molecule (or an argon atom). The efficiency of the collision is about 0.5. In view of these results, it is highly probable that this carrier is an oxygen atom. In the photosensitized reaction one-fifth of the collisions between oxygen molecules and excited mercury atoms results in the initiation of a chain. These results are shown to be quantitatively consistent with the shape and also the position of the upper limiting explosion curve, except that the limiting pressure is a little higher than that calculated by a strict application of the theory of branched chains. The upper limit is displaced to higher pressures by illumination of the mixture, a phenomenon not predicted by theory. The effect is of short duration, <2 sec. and it is not exhibited at the lower limit. The significance of this result is discussed in relation to the theory of the reaction.
The Photoisomerization of the o-Nitrobenzaldehydes I. Photochemical Results
Authors: Leighton Philip A. , Lucy Frank Allen
Published: November 2004

Numerous disparate explanations have been advanced for the observed quantum yield in the photoisomerization of o-nitrobenzaldehyde. The authors decided to gather further data on this reaction, varying such factors as the weight of the molecule and the physical state of the material. The results indicate that the reaction occurs intramolecularly, but that for o-nitrobenzaldehyde itself the quantum efficiency is nearly one-half in all cases. A detailed consideration of the mechanism is deferred to the second portion of this paper.
The Photoisomerization of the o-Nitrobenzaldehydes II. Mathematical Treatment
Authors: Lucy Frank Allen , Leighton Philip A.
Published: November 2004

The probable course of the reaction, from the absorption of light to the formation of the isomer, is followed in roughly quantitative detail. In this manner, the low quantum yields, surprising at first sight for intramolecular processes, are explained by a consideration of the physical properties of the molecules.
Combination-Scattering and ``Association of Molecules''
Authors: Leitman S. I. , Ukholin S. A.
Published: November 2004

The molecular association of polar liquids was studied by the combination-scattering (Raman-spectra) method. In the spectra of a water solution of acetic acid the lines corresponding to the wave number 623 cm—1 changed their relative intensity at a change of the concentration of solution. This wave number is therefore characteristic of acetic acid complex molecules. No associative lines were observed in the combination spectra of nitrobenzol solution in CCl4.
The Ultraviolet Absorption of Methane
Authors: Duncan A. B. F. , Howe John P.
Published: November 2004

The absorption spectrum of methane from 1450A to 850A is found to be entirely continuous and all excited states up to the first ionization potential are repulsive.
Entropy and the Absolute Rate of Chemical Reactions I. The Steric Factor of Bimolecular Associations
Authors: Rice O. K. , Gershinowitz Harold
Published: November 2004

The equilibrium constant for a bimolecular association may be expressed in terms of the energy change, ΔE, and standard entropy change, ΔS°, on association. On account of the well-known relation between the equilibrium constant, and the rate constants of the bimolecular association and its reverse, the corresponding unimolecular decomposition, the values of these rate constants could be determined separately, if one could divide each of the terms, ΔE and ΔS°, into two parts, in the proper way. The proper method of dividing ΔE is known; this paper is concerned with the division of ΔS°. Considered from a statistical point of view, the entropy of a system depends upon the volume in phase space available to the system under fixed thermodynamic conditions. The separate rate constants will depend upon the fraction of the phase space in which it is possible for the reaction under consideration to take place. Application of this principle leads to an interpretation of the collision number and the steric factor of bimolecular association reactions. The known bimolecular associations have been discussed from this point of view.
A Summary of the Entropies of Aqueous Ions
Authors: Latimer Wendell M. , Schutz Philip W. , Hicks J. F. G.
Published: November 2004

A critical survey has been made of existing data on the heats, free energies and entropies of reactions involving aqueous ions. These data lead to remarkably consistent values for the ionic entropies. The entropies of 20 positive ions and 12 negative ions have been tabulated.
On the Statistical Basis of the Theory of Electrolytes
Authors: Halpern Otto
Published: November 2004

In the following paper the author investigates how far the various statistical-thermodynamic methods hitherto proposed are suitable for application to strong electrolytes. The significance of the ionic radius is, in many instances, far more important than has hitherto been assumed. When the influence of the ionic radius is negligible conditions are derived from dimensional considerations which considerably restrict the functional form of the free energy. Furthermore, proceeding from conditions of integrability, thermodynamics appreciably limits the number of possible expressions for the ionic potential. The disregarding of these limitations has been responsible for certain paradoxes in the literature on this subject. A new fluctuation formula for the electric potential of the ions is derived and conclusions are drawn from it as to the correctness of existing theories. In connection with this last a deduction proposed by Fowler is reviewed. Kramers' theory of electrolytes is tested with respect to its agreement with the theorems here developed. Finally, a review of the statistical and thermodynamical basis of Bjerrum's theory of ionic association is presented.
A Quantum Theory of the Latent Photographic Image
Authors: James T. Howard
Published: November 2004

An explanation of the process of photographic exposure on the basis of a true photochemical reaction is offered. It is pointed out that the apparent failure of the Einstein equivalence law in the case of photographic exposure for short intervals is not real, and an equation is derived on the basis of the assumption that the absorption of one quantum by a sensitivity center of the grain produces an activated, but unstable state which renders the grain as a whole developable. The assumption that an activated grain may revert to an undevelopable state is an important part of the present theory, and evidence in favor of this assumption is cited. The theory that the photographic process is auto-catalytic is criticized on the basis that the point of inflection of the H and D curve indicated by this theory is much higher than the point found experimentally. A preliminary treatment of the Herschel effect is given on the basis of the proposed theory, and an equation holding under special conditions is derived. The explanation of the intermittency effect as put forward by Blair and Hylan is still valid in the light of the present theory. Data taken from reliable sources are given to show that the general equation holds over wave-lengths ranging from red light to x-rays, and emulsions from Azo to Eastman Portrait.
On the Theory of Glass Electrodes
Authors: Gross Philipp , Halpern Otto
Published: November 2004

A glass electrode is considered schematically to be a difficultly soluble electrolyte which absorbs water and further salts present in an adjacent solution. The potential is the distribution potential at the boundary surface between the glass and the solution. According to the theory presented this potential varies if certain reasonable assumptions are made concerning the value of the constants occurring (dissociation constants in the glass, distribution constants between glass and water) over a wide range of concentration in acid and neutral solutions in the same manner as that at an H2 electrode. The variation of the potential differs from the latter in a strongly alkaline solution, in the manner ascertained experimentally and predicted in previous communications. The extremely simplified model describes quantitatively with one empirical constant the potentials hitherto observed. It is shown that the systems are completely explicable on the basis of the usual thermodynamic picture of equilibrium. Attempts on the other hand to describe the phenomena on the basis of diffusion potentials have not led to satisfactory results.
The Theory of the Electrolytic Separation of Isotopes
Authors: Bell Ronald P.
Published: November 2004

(1) Gurney's treatment of overvoltage has been applied to the relative rates of discharge of two isotopes. As a first approximation it is found that the separation efficiency should be nearly independent of the electrode material and the current density. This agrees with the data at present available for the separation of the isotopes of hydrogen. (2) A more rigid treatment predicts small variations of the efficiency with the nature of the electrode and the current density, but is not at present able to predict these variations quantitatively. (3) The application of the theory to other isotopes is indicated, and a rough estimate given of the possibility of separating Li6 and Li7 by electrolysis.
The Limiting Gas Density Method for Molecular Weights
Authors: Birge R. T. , Jenkins F. A.
Published: November 2004

In this, the first of a series of papers, we give a general discussion of the limiting gas density method for the determination of molecular weight. The various methods that have been used, or might well be used for the reduction of the data, are compared in a systematic way, and the most desirable methods for such work are pointed out. These methods are then applied to selected data given in the literature, and are compared with the actual published calculations and results. The paper closes with certain conclusions drawn from the preceding analysis.
On the Statistical ``Interaction Between Ions and Molecules'' in Media of Small Dielectric Constant
Authors: Halpern Otto , Gross Philipp
Published: November 2004

In this paper the general theory of the interaction between ions and molecules in solution is discussed with particular reference to the theory of Debye on the salting-out effect. Formulae are developed for the free energy of the interaction between ions and dipoles. The formulae are applied to the dissociation equilibrium of an electrolyte in a medium of low dielectric constant.
A Calculation of the Intensities of Reflection of a Series of n-Aliphatic Alcohols
Authors: Wilson Donald A. , Ott Emil
Published: November 2004

Comparison between observed and calculated intensities of c spacings of the α-modification of a series of n-aliphatic alcohols gives excellent values for the coordinates (projected on the c axis) of the constituent atoms.
Experimental Measurement of the Lattice Energies of RbBr and NaCl
Authors: Helmholz Lindsay , Mayer Joseph E.
Published: November 2004

By measuring electrically the ion emission through an orifice in an equilibrium chamber at high temperature containing salt vapor the lattice energies are calculated. The values obtained are 151.3 kcal. for RbBr and 181.3 kcal. for NaCl. The probable error is about 3.0 kcal. for both measurements, and the maximum error in the neighborhood of 7.5 kcal. The corresponding electron affinities are 84.2 kcal. for Br and 88.3 kcal. for Cl.
The Raman Spectra of Some Compounds Containing Carbon-Bromine Bonds. Possible Changes of the Vibration Frequencies in Ionic Solutions
Authors: Voge Hervey H.
Published: November 2004

Raman spectra of methyl bromoacetate and methyl phenylbromoacetate are reported. The carbon-bromine bond line of the former is similar to that for ethyl bromide, while in the latter it does not appear in its normal position at all. The spectra of methyl alcohol and ethyl bromide have been accurately redetermined; some minor additions result. Shifts of the methyl bromoacetate and methyl alcohol lines in solutions of bromides are found.
The Para-Ortho Hydrogen Conversion by the Hydrogen Iodide Reaction and by Iodine Atoms
Authors: Rosenbaum E. J. , Hogness T. R.
Published: November 2004

The rate of conversion of para to ortho hydrogen was determined in the presence of equilibrium concentrations of hydrogen iodide and iodine. From these data, velocity constants and collision efficiencies for the conversion by iodine atoms were calculated. The results are in agreement with a theoretical equation derived by Wigner.
On the Activation Energy of Unimolecular Reactions
Authors: Gershinowitz H. , Rice O. K.
Published: November 2004

By using the principle of microscopic reversibility, unimolecular decompositions are considered from the point of view of the reverse reaction, which is a bimolecular association. In cases where the immediate product of the decomposition is a pair of free radicals, it is assumed that the probability of these free radicals recombining upon collision is independent of their energy. An explicit expression for the activation energy in terms of the energy of reaction and the thermal properties of the molecules involved is thus obtained. From this one may calculate the energy of activation at absolute zero and the energy necessary to break the bond which falls apart in the reaction, quantities which may differ considerably from each other and from the energy of activation at the temperature of reaction. The results are applied to several cases of interest, and are critically compared with those of the earlier theories of Rice and Ramsperger, Kassel and Rice. A brief discussion is given of the calculation of the rate constant as a function of pressure, and its modification according to the point of view of the present paper.
The Experimental Determination of the Heat Capacity of Gaseous Ozone
Authors: Lewis Bernard , von Elbe Guenther
Published: November 2004

The mean heat capacity of ozone between 300 and 476°K has been determined from explosions of mixtures of ozone and oxygen in a spherical bomb by the method the authors described in a previous paper. The value obtained is 10.94 calories per mol of ozone. The value obtained from band spectra is 10.39 calories per mol. The difference cannot be accounted for by incorrect assignment of the optical frequencies of ozone, and it is larger than the probable experimental error. It is proposed that the difference may be due to a contribution to the heat capacity of an electronic level lying close to the ground state of the ozone molecule. It is estimated that this supposed level has an energy of 0.1 to 0.2 volt. The existence of low-energy electronic levels probably implies an isosceles triangle structure and paramagnetic properties of the ozone molecule in the normal and the low excited states.
The Infrared Absorption of Water from 2.5μ to 6.5μ
Authors: Plyler E. K. , Craven C. J.
Published: November 2004

A study has been made of the infrared absorption bands of water from 2.5μ to 6.5μ and new bands have been found at 3.30μ, 5.56μ and 5.83μ. The band at 4.7μ showed an irregular envelope and may contain several components. The 3μ band showed a shift with thickness and is probably made up of four components. The change in position of the maximum in the 3μ region with thickness is explained as due to difference in sharpness of the components which constitute the band. The band at 6.15μ did not show the corresponding shift with thickness.
The Infrared Absorption of Acid Solutions
Authors: Plyler E. K. , Barr E. S.
Published: November 2004

A study has been made of the absorption of aqueous solutions of HCl, HF, HBr, H2SO4, HNO3, NaCl and NaBr in the region from 1.7μ to 6.5μ. Also HCOOH, C6H5COOH have been studied from 5μ to 6.5μ. No absorption bands were found for HCl and HBr in the regions of 3.5μ and 3.8μ, respectively, where there are strong bands in the gaseous state. All of the acid solutions showed a strong band at about 5.5μ. The position of this band varied slightly with the solute and the sharpness of the band was different for each acid. Another band was found at 2.40μ for the solutes. The 5.5μ band is explained as due to the undissociated molecule attached to a water molecule and the 2.40μ band as due to the same effect or to a hydrogen ion attached to a water molecule.
Modified Scattering by Crystalline HCl and HBr
Authors: Callihan Dixon , Salant E. O.
Published: November 2004

The values of the modified frequencies of radiation scattered by crystalline HCl and HBr at temperatures just below their freezing points are found to be 2784 cm-1 and 2480 cm-1, respectively, for the long wave edge. As with gases and liquids, the intensities of scattering are in the reverse order of intensities of absorption and the difference in the Raman shifts with change of state is too great to be attributed to Lorentz-Lorenz forces alone. The Raman band of crystalline HCl corresponds to the high frequency branch of two absorption bands found by Hettner, not to the center of the bands; on the possibility that, because of this correspondence, this branch is a Q-branch, the temperature variations of the absorption bands and the heat capacity at low temperatures can be accounted for. The non-existence of a third branch, for the R, is noted.
The Natural Separation of the Isotopes of Hydrogen. I. The Concentration of Deuterium in Benzene, Kerosene and Honey
Authors: Dole Malcolm
Published: November 2004

Waters obtained in the combustion of benzene, kerosene and honey have been analyzed for their deuterium content by density measurements. In all cases the concentration of deuterium is greater in these substances than it is in distilled water from Lake Michigan.
Continuous Flow Methods of Concentrating Deuterium
Authors: Anderson Leigh C. , Halford J. O. , Bates John R.
Published: November 2004

Experimental arrangements for the concentration of deuterium by electrolysis in a continuous flow system are described. These are found to be as efficient as straight electrolysis in single cells and involve considerably less manual labor. An arrangement for the recovery of off hydrogen of high deuterium content which is practically free from danger of explosion is also given.
The Free Energy of Sulfur Monoxide and the Dissociation Constants of S2
Authors: Montgomery C. W. , Kassel Louis S.
Published: November 2004

Values of (F0—E00)/T are calculated from spectroscopic data for S2, SO and S, and equilibrium constants obtained for the reactions 2SO=S2+O2;  2SO=12S2+SO2;  S2=2S.It is found that SO is stable with respect to the first mode of decomposition, but unstable with respect to the second except at higher temperatures.
Deuterium as an Indicator of Mechanism in the Photo-Decomposition of Ammonia
Authors: Taylor Hugh S. , Jungers Joseph C.
Published: November 2004

By studying the photolysis of ammonia-deuterium mixtures it has been experimentally demonstrated that the reaction NH2+H = NH3 is an important feature of the overall photo-decomposition and provides one reason for the low quantum yield observed in the photo-process. It has further been shown that the interaction of hydrogen atoms with ammonia molecules is a process of low efficiency at room temperatures.
The Raman Spectrum of Heavy Water Vapor
Authors: Rank D. H. , Larsen K. D. , Bordner E. R.
Published: November 2004

The Raman spectrum of heavy water vapor was obtained by using water having a d2020 = 1.073, at two atmospheres pressure. A line Δv = 2666 cm—1 was found for D2O and Δv = 2718 cm—1 for HDO. The other line expected from the work of Wood on liquid heavy water in the region Δv = 3700 cm—1 was not found. The line Δv = 3650 cm—1 of H2O was resolved into a doublet Δv = 3646.1 cm—1 and Δv = 3653.9 cm—1. An attempt has been made to explain the Raman spectrum of H2O empirically by using the data of Mecke on the infrared absorption spectrum of H2O.
Quantum Theory of the Latent Photographic Image
Authors: James T. Howard , Coleman J. J.
Published: November 2004

A general formulation involving quantum ideas is given for the relation between the amount of photolytic action in latent image formation and the amount of light producing it. A method of deducing the number of ``effective'' quanta per grain necessary to produce developability is given. Slow process emulsions require, in general, the absorption of from 3 to 4 ``effective'' quanta. This number agrees with that found for physical development by Reinders and Hamburger. Faster emulsions require a smaller number (1 to 2), showing presumably the presence of more highly developed sensitivity centers. The number for any emulsion should depend to some extent upon the developer used. Parametric equations are given which relate the amount of photolytic product to the number of developable grains. These equations lead to a characteristic curve which has a point of inflection when the number of ``effective'' quanta required per grain is greater than one but none when the number is equal to one.
The Kinetics of the Homogeneous Thermal Decomposition of Ethyl Ether at Pressures up to Two Hundred Atmospheres
Authors: Steacie E. W. R. , Solomon Ernest
Published: November 2004

A new and simple apparatus is described by means of which it is possible to investigate the kinetics of homogeneous gas reactions up to pressures of several hundred atmospheres. With this apparatus the decomposition of gaseous ethyl ether has been investigated at 426°C over the pressure range 2000 to 14,500 cm. The rate of reaction increases rapidly with pressure up to 10,000 cm and then increases more slowly. The rate at 14,500 cm is approximately 50 times greater than the previously assumed value at infinite pressure. It is shown that by assuming that the number of degrees of freedom involved varies with the time between molecular collisions it is possible to explain these results. Further investigations are in progress.
The Surface Tension of Debye-Hückel Electrolytes
Authors: Onsager Lars , Samaras Nicholas N. T.
Published: November 2004

As has been shown by Wagner, the increase of the surface tension caused by the addition of a strong electrolyte to water is mainly due to the repulsion of ions from the surface by the electrostatic image force. Due to the shielding action of the ``ionic atmospheres,'' of radius 1/κ, the image force is appreciable only within distances of the order 1/κ from the surface. The computations become very complicated if, as Wagner did, one attempts to allow for the variation of κ with the depth in accordance with the decreased concentration of ions in the surface layers. Fortunately, a detailed analysis of the problem shows that this refinement may be dispensed with as a first approximation, and that the formulas thus derived will be accurate for not too high concentrations. The same analysis tends to show that Wagner's procedure supplies only a part of the intended correction, so that the results will be applicable only over a slightly wider range of concentrations than the convenient explicit formulas which are derived from the simplified theory. In the limit of low concentrations, the increment of the surface tension is proportional to c log c. The theory accounts reasonably well for the observed surface tensions up to 0.2 N concentration. The discrepancies, while partly due to mathematical approximations, may be of some physical significance and would mean that for small distances the repulsion from the surface is greater than expected from Coulomb's law. Nevertheless, the agreement obtained verifies Coulomb's law for univalent ions at distances greater than a molecular diameter from the surface.
Comparison of X-Ray Diffraction Curves of Water and Deuterium Oxide at 25°C
Authors: Stewart G. W.
Published: November 2004

The difference in freezing point temperatures, maximum densities and molecular volumes and other physical constants of water and deuterium oxide indicate that the molecular forces do not remain entirely invariant with the isotopic change in mass. A comparison of the diffraction of x-ray curves for the two substances at 25°C indicates that the liquid structure of deuterium oxide is much like that of water. The peaks in the deuterium oxide curve are slightly sharper, apparently explicable in the fact that, at 25°C, this substance, compared with water, is nearer to its freezing point.
The Infrared Absorption Spectrum of Water Containing Deuterium
Authors: Ellis Joseph W. , Sorge Barthold W.
Published: November 2004

Absorption percentages for the region 1–10μ are presented for one sample of water, 60 percent of whose hydrogen is deuterium, and for a second sample containing 99.5 percent deuterium oxide. Maxima are picked out as the three fundamental frequencies for the molecules DOD and HOD. These are compared with values predicted by an isotopic shift calculation based on data chosen from the spectrum of ordinary water. All other higher frequency maxima are interpreted as overtones or combination bands, but only after a fourth fundamental frequency is chosen in the examples of HOH and DOD.
The Constancy of the Polarization of Non—Polar Molecules
Authors: Smyth C. P. , McAlpine K. B.
Published: November 2004

The dielectric constants of the vapors of n-hexane and n-heptane are measured over a range of temperature and used to show that the molecules of these substances have no detectable dipole moments. The constancy of the polarizations of non-polar vapors in contrast to the slight rise with temperature of the polarizations of the same substances in the liquid state is attributed to the elimination of the intermolecular action which lowers slightly the polarizability of the molecules in the liquid state.
The Velocities of Adsorption of Hydrogen and Deuterium on Hydrogenation Catalysts
Authors: Pace James , Taylor Hugh S.
Published: November 2004

The velocities of adsorption of hydrogen and deuterium have been measured on the hydrogenating oxide catalysts, chromium oxide and zinc-oxide-chromium oxide and on a supported nickel catalyst. The velocities of adsorption of the two gases are identical, within the experimental error, over a range of temperature on each surface. The fundamental importance of these observations in the theory of activated adsorption and in chemical kinetics generally is emphasized.
The Rate of Adsorption of Ethylene by Silica and Nickel
Authors: Steacie E. W. R. , Stovel H. V.
Published: November 2004

The adsorption of ethylene by silica has been investigated from 20 to 300°C. Over this range equilibrium is reached practically instantaneously in all cases. The adsorption of ethylene by reduced nickel has been investigated from —80° to 150°C. Definite slow effects and temperature hysteresis were observed. Since diffusion into the crystal lattice (``solubility'') is extremely unlikely in this case, more definite conclusions can be drawn than have been possible in previous investigations.
The Solubility of Biphenyl in Non-Polar Solvents
Authors: Warner J. C. , Scheib R. C. , Svirbely W. J.
Published: November 2004

The solubilities of biphenyl, between 30° and 60°, in benzene, carbon disulphide, carbon tetrachloride, heptane, dioxane and p-dichlorobenzene have been determined. The solubilities, in all cases, are lower than ideal. The freezing point-composition diagram for the system biphenyl-p-dichlorobenzene has been determined. These components yield a simple eutectic at 27.7° and at 42.5 mole percent biphenyl. Hildebrand's equation, based upon the simple Baud-Heitler equation for the heat of mixing, yields fairly satisfactory results for solutions of biphenyl in benzene, carbon disulphide, p-dichlorobenzene and dioxane. The results are not very satisfactory when the equation is applied to the solutions of biphenyl in carbon tetrachloride and heptane. Hildebrand's more recent equation, based upon the Menke probability function, yields fairly satisfactory results considering the nature of the assumptions made in its derivation. It is concluded that regular solution behavior should be expected only when the molecules of the constituents, in addition to being non-polar, possess spherical symmetry.
The Crystal Structure of Cyanuric Triazide
Authors: Hughes Edward W.
Published: November 2004

Hexagonal cyanuric triazide has been examined by means of Laue, rotation and oscillation photographs and by a few spectrometer measurements. The dimensions are a = 8.70A and c = 5.98A. The space group is H63/m. There are two C3N3(N3)3 in the cell. The ten parameters have been determined by a qualitative Fourier analysis and the dimensions and angles of the molecule are given.
A Direct Experimental Determination of Electron Affinities, the Electron Affinity of Iodine
Authors: Sutton Paul Porter , Mayer Joseph E.
Published: November 2004

By observing the ratio of the negative ion emission to the electron emission from a thermionic surface of known temperature in an atmosphere of electronegative molecules of known pressure the electron affinity of the atoms can be calculated. A magnetron set up has been used to distinguish electron and ion currents. With a tungsten filament at about 2000°K, and an iodine atmosphere of about 1 micron pressure, the electron affinity of iodine atoms has been found to be 72.4±1.5 kcal.
The Absorption Spectrum of Eu+++ in Crystalline Eu2(SO4)3–8H2O
Authors: Meehan E. J.
Published: November 2004

The absorption spectrum of Eu2(SO4)3–8H2O has been studied over the temperature range 14°K—290°K. Measurements of the absorption lines are given for five temperatures. Intensity variations caused by a change in temperature have been used to establish definitely the existence of levels 21 cm—1 and 41 cm—1 above the basic one, and to indicate the existence of 67 cm—1, 86 cm—1, and possible higher levels. An unusual feature of the spectrum is the constant energy difference occurring between many lines which are most intense at the lowest temperatures.
The Structure of Potassium Hexachlorothalliate Dihydrate
Authors: Hoard J. L. , Goldstein Leonard
Published: November 2004

Potassium hexachlorothalliate dihydrate is shown from x-ray data to possess a body centered tetragonal unit of structure with a0 = 15.841±0.020A, c0 = 18.005±0.020A containing 14 K3TlCl6–2H2O. A structure with nineteen determinable parameters is developed from D4h17 — I 4/mmm, and accounts satisfactorily for observed intensity data. TlCl63— ions occur as well-defined groups. 24 of the 42 K+ ions are closely surrounded by 8 Cl—, 16 K+ by 7 Cl— and 2 H2O, and the remaining 2 K+ by 6 H2O; these K(H2O)6+ groups are situated in regions of definitely negative potential. The structure is very compact, but has quite satisfactory interatomic distances throughout. The evidence from this and from a previous structural determination of Cs3Tl2Cl9 shows that thallic thallium tends to form six stable covalent bonds with chlorine with a Tl–Cl separation of about 2.55A, in agreement with the covalent radii of Pauling and Huggins. It is shown also that a compound of empirical formula Rb3TlBr6–(8/7)H2O probably possesses essentially the same type of structure as K3TlCl6–2H2O; dimensional relations in the bromothalliate permit the alkali ions of 2(b) to coordinate eight rather than six molecules of water.
The Difference in Vapor Pressures of Ortho and Para Deuterium
Authors: Brickwedde F. G. , Scott R. B. , Taylor H. S.
Published: November 2004

The difference between the vapor pressures, ΔP(e — n), of the 20.4°K equilibrium mixture and the normal mixture of the ortho and para varieties of D2 were determined from 15° to 20.4°K. ΔP(e — n) varied from 0.3 mm of Hg at 15°K to 3.8 mm at 20.4°. ΔP(e — n) for deuterium is small as compared with ΔP(e — n) hydrogen, but [ΔP(orthopara)/P(n)] for deuterium is approximately equal to [ΔP(para-ortho)/P(n)] for hydrogen at the same temperature. Further measurements were made on the uncatalyzed change with time of the vapor pressure of liquid normal deuterium. The change for deuterium is less than one mm of Hg in 200 hours, whereas the vapor pressure of liquid normal hydrogen increases one mm in 4 hours. This large difference in rates is attributable to the difference in magnetic moments of the proton and deuteron. If Wigner's theory of the ortho-para conversion by paramagnetic molecules in the gaseous phase is extended to the liquid phase to calculate the relative rates of change of the vapor pressures of liquid normal deuterium and liquid normal hydrogen, a ratio of 1/1000 is obtained for the ratio of the rate of change for deuterium to the rate of change for hydrogen.
The Infrared Spectrum of Heavy Water
Authors: Barker E. F. , Sleator W. W.
Published: November 2004

Samples of water vapor containing 90 and 40 percent of deuterium have been examined in the infrared, and the absorption bands v2 and v3 for D2O and v2 and v1 for HDO have been located. The position of v1 for D2O is known from Raman scattering. Of the nine fundamental frequencies for the three varieties of water, eight have now been observed. The ninth, v3 for HDO, should lie very close to the corresponding band for H2O and is apparently completely masked. Computed values of these frequencies already available agree very well with the measured ones. A fair degree of resolution is obtained in the bands v2. The fine structure observed agrees approximately with that predicted by using the molecular dimensions obtained by Mecke, viz., OH distance ∼0.95×10—8 cm and apex angle ∼105°. The magnitude of the interactions is so great, however, that precise determinations of these constants must await a more complete solution of the mechanical problem.
The Infrared Absorption of Cyanides and Thiocyanates
Authors: Gordy Walter , Williams Dudley
Published: November 2004

Aqueous solutions of seven inorganic cyanides, two thiocyanates, and one cyanate were studied in the region from 1.2μ to 7.5μ. Two organic cyanides and an organic thiocyanate were studied in the same region. In all the materials a characteristic absorption band was observed in the region from 4.38μ to 4.90μ. The exact position of the band was found to be different for the various substances. This characteristic absorption was attributed to changes in the vibrational energy of the bound CN group. An additional band appearing only in the highly ionized cyanide solutions was attributed to the free CN ions. In the cyanate solution a double band appeared in the region of 7μ which was not characteristic of the cyanide or thiocyanate solutions. Hydrolysis and solvation effects were observed in some of the solutions.
The Raman Spectra of Oxalic Acid
Authors: Hibben James H.
Published: November 2004

The Raman spectra of anhydrous oxalic acid, its aqueous and alcoholic solutions, and oxalic acid dihydrate were determined. The spectra from the aqueous solution and anhydrous oxalic acid show that the two carboxyl groups do not behave identically. Peculiarities in the spectrum of the dihydrate are indicated. In the alcoholic solution both carboxyl groups behave similarly. The magnitude of the force constants in the carbonyl groups are consistent with the strength of this acid. Various explanations of these anomalies are discussed briefly.
Monomolecular Films of Molecules Which Lie Flat on the Surface of Water I. Surface Pressures and Potentials of Films of Long Molecules: Polymers of ω-Hydroxy Decanoic Acid
Authors: Harkins William D. , Carman Everett F. , Ries Herman E.
Published: November 2004

Film pressures and surface potentials have been measured for a series of linear polymers of ω-hydroxy decanoic acid, ranging in molecular weight from 780 to 25,200. The molecules are oriented parallel to the surface. An improved form of the apparatus of Harkins and Fischer was used. The chief modification in the procedure was the use of two radioactive polonium electrodes over the film. The pressure-area relations show that the area per molecule in the condensed films is nearly proportional to the molecular weight and that the compressibility of the films is large. The film density is found to be lowest for the polymers of smallest molecular weight. The films are not very sensitive to changes in hydrogen ion concentration, but on changing from an acid to an alkaline substrate the films in the expanded state give higher molecular areas at given pressures, and the pressures for film collapse are considerably higher. Dimensions of the molecules are calculated and a complete table of mean values is included. The vertical cross section of the molecules varies between 19.4 and 19.9 sq. A or is nearly the same as the horizontal cross section (20.5) of vertically oriented molecules such as stearic acid. Some differences between films with perpendicular orientation to the surface and those with parallel orientation are tabulated. The surface potentials of the polymer films rise to between 400 and 450 mv, although the surface density of the polar groups is only 1/3 to 2/5 that of stearic acid type films, which also give potentials of about 400 mv. The contribution of each polar group is, therefore, considerably greater than that of the dipole of the vertically oriented stearic acid molecule. The surface potential of a condensed film was found to increase about 13 percent less rapidly than the surface density of the dipoles.
Electron Diffraction by Gases
Authors: Maxwell L. R. , Hendricks S. B. , Mosley V. M.
Published: November 2004

The method of electron diffraction is used for determining the C–O–C valence angle (α) in 4,4′ diiododiphenyl ether [(C6H4I)2O] and the molecular structures of phosphorus (P4) and arsenic (As4). The electron diffraction photographs were analyzed by four different methods as follows: (1) Visual measurements, (2) measurements of densitometer records, (3) conversion of densitometer records into relative intensity curves, (4) comparison of transformed intensity curves obtained by multiplying the intensity of scattering by [(1/λ) sin θ/2]2 which produces prominent maxima for measurement. The valence angle α was found to be 118±3° for 4,4′ diiododiphenyl ether, definitely greater than the oxygen valence angle found for simpler types of molecules. Phosphorus and arsenic molecules were found to have a regular tetrahedral structure within the limits of experimental error, the atomic separations being 2.21A and 2.44A, respectively, [methods (1) and (2) were used for the case of arsenic]. The minimum atomic distances as found by crystal structure analysis for phosphorus and arsenic are approximately the same as the atomic separations obtained for the gas molecules, showing in addition that these distances do not change greatly when the bond angle decreases from 100° to 60°.
Nonadiabatic Reactions. The Decomposition of N2O
Authors: Stearn Allen E. , Eyring Henry
Published: November 2004

The experimental and theoretical absolute rates for the nonadiabatic decomposition of N2O are shown to be in good agreement. The amount of chemical inertia present in other reactions involving the singlet-triplet transition of oxygen is considered. A convenient method of constructing potential functions for polyatomic molecules which fit the spectroscopic data, and which reduce in the proper way for the various dissociation processes, is indicated, and is carried through for the N2O molecule.
On the Two-Quantum Σ-States of the Hydrogen Molecule
Authors: Present Richard D.
Published: November 2004

A wave function in the form of a series with coefficients to be determined by the variational method is used to calculate the dissociation energies of the hydrogen molecule in two of its excited states: 1sσ2sσ 3Σg+ and 1sσ2pσ 1Σu+. In the former case an 11-term wave function gives an energy less than 0.02 e.v. from the most probable experimental value and lying within the limits of experimental error. For the second state an energy less than 0.08 e.v. from experiment is obtained by means of a function comprising 18 terms. The interelectronic distance has been introduced explicitly into the wave function and the role that it plays in reducing the energy is discussed at length. The limits of accuracy of the calculation with reference to convergence and nuclear motion are considered. Explicit wave functions are given for the two states.
Molecular Arrangement and X-Ray Diffraction in Ionic Solutions
Authors: Prins J. A.
Published: November 2004

Solutions containing heavy ions in water were examined with Cu Kα radiation, care being taken to avoid effects of general radiation. The diffraction patterns of saturated solutions of Th(NO3)4 and UO2(NO3)2 consist mainly in a pronounced ring, shifting to smaller angles and getting fainter with increasing dilution. This indicates a more or less regular arrangement of the ions in the liquid, for which the name ``superarrangement'' will be used to distinguish it from the arrangement with smaller periodicity of the water molecules. Both arrangements are of course of the ``liquid-type.'' The above results show that the ``super-arrangement'' expands and gets more diffuse with increasing dilution, as might be expected. Another kind of pattern is exhibited by solutions of AgNO3, Pb(NO3)2, Ba(NO2)2 and lead acetate. Here the intensity does not show pronounced maxima and minima. More especially it does not decrease markedly when the diffraction angle tends to zero. An explanation is offered, assuming the existence of a large fraction of undissociated molecules, with a gaseous distribution. A third class is formed by solutions of LiI, RbBr, LiBr and other alkali-halides. These yield a broad ring the position of which is independent of concentration. It is shown that these facts may be accounted for by ascribing this ring mainly to the interference between the scattering from a heavy ion and that from the water molecules around it. To clear up some of the above points a few experiments are made with solutions of analogous light ions. Finally a general theory on diffraction by solutions is formulated and applied to some of the experimental cases.