bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of the Photosensitized Reaction of Hydrogen and Oxygen, and Deuterium and Oxygen
Authors: Evans Meredith Gwynne
Published: November 2004

The rates at which hydrogen-oxygen and deuterium-oxygen mixtures react when illuminated in the presence of mercury vapor, have been measured. There is found to be very little difference between the rates under these conditions and the temperature coefficients of the two reactions are, to within the accuracy of this work, equal. Various mechanisms are discussed in the light of this experimental observation.
Two Theorems Concerning Electrolytes
Authors: Fuoss Raymond M.
Published: November 2004

(1) Fluctuations in the average total electrostatic energy E of the free ions of an electrolytic solution as calculated by the theory of Debye and Hückel are negligibly small in accessible concentration ranges. If δE={Ē2—(Ē)2}½, then δE/Ē=(—kT/2Ē)½; i.e., the ratio of the fluctuation in energy to the total energy is of the order of the square root of the ratio of the kinetic energy per degree of freedom of a single molecule to the total electrostatic energy of the system. (2) A general relationship connecting free energy F and average electrostatic energy Ē is derived; for the case where the average potential around an ion is given by the Debye-Hückel formula, F=2Ē/3.
X-Ray Studies of the Molecular Arrangement in Liquids
Authors: Katzoff S.
Published: November 2004

An improved technique has been developed for taking x-ray diffraction photographs of weakly absorbing liquids. Photographs of water, heptane, decane, benzene and cyclohexane have been taken and several hitherto unobserved details have been discovered. The photographs of water have been mathematically investigated by the method of Zernike and Prins, and it was concluded that nearly every molecule has four others around it. No evidence was found either for the definite ``quartz-like'' arrangement or for the extensive degree of close packing which are postulated by Bernal and Fowler. With the organic compounds there was apparent in every case a striking resemblance of the outer parts of the photographs to electron diffraction photographs of the corresponding vapors. This is in agreement with Debye's prediction and argues for a relatively low degree of periodicity in the liquid structure. It has been shown further that the two outer bands which occur in the photographs of the normal hydrocarbons should appear whenever the molecules of the liquid consist largely of lengths of straight saturated hydrocarbon chain. Some discussion of the structure of the organic liquids has been given. In particular, a theory on the structure of liquid benzene has been postulated and found, using the method of Zernike and Prins, to predict with satisfactory accuracy the observed photograph. The viewpoint which has been found useful in the present discussions is that, to a predominating extent, adjacent molecules in the liquid are held together in very nearly the same manner as in the crystal, while, except for this, the arrangement is random.
The Theory of the Glass Electrode. III Statistical Explanation of the Alkaline Solution Behavior
Authors: Dole Malcolm
Published: November 2004

The application of Gurney's quantum and statistical mechanical theory of electrochemistry to the glass electrode results in an equation for the alkaline solution behavior identical with one previously obtained by the author except that the constants of the equation have a more reasonable significance. A qualitative explanation of the inability of negative ions to affect the glass electrode potentials is also given.
Raman Effect of Acetylenes. I. Methyl-, Dimethyl- and Vinyl-Acetylene
Authors: Glockler George , Davis H. M.
Published: November 2004

An improved helical discharge tube containing neon and mercury with a saturated solution of sodium nitrite as filter served as a monochromatic source of radiation (4358 Hg). A mechanical filter avoided overexposure of the exciting radiation. The vibration frequencies were studied on the basis of the symmetry properties of the molecules and the usual assignments have been made. Faint rotation lines were found accompanying the C ⋮ C vibration in liquid dimethyl-acetylene. They are interpreted as rotation of the six hydrogen atoms around the figure axis of the molecule. The moment of inertia is I = 10—39 g×cm2. The three compounds were studied in the liquid state.
The Calculation of Thermodynamic Quantities from Spectroscopic Data for Polyatomic Molecules; the Free Energy, Entropy and Heat Capacity of Steam
Authors: Gordon A. R.
Published: November 2004

The methods already developed by Gordon and Barnes for computing thermodynamic quantities from the band spectrum of a diatomic molecule are extended to deal with the case of the triatomic unsymmetrical rotator. The free energy, entropy and heat capacity of steam are computed for the temperature range 298.1–1500°K from the spectroscopic data of Mecke and his associates. From the free energy so calculated, the known spectroscopic free energies of carbon monoxide, carbon dioxide and hydrogen, and the thermal data of Rossini, revised values of the equilibrium constant for the water-gas reaction are computed. The numbers so obtained are in close agreement with the experimental results of Neumann and Koehler and of Emmett and Schultz.
Internal Equilibria and Partial Vapor Pressures of Mixtures of Primary Normal Alcohols with Normal Paraffin Hydrocarbons
Authors: von Elbe Guenther
Published: November 2004

1. Heats of mixing for mixtures of primary n-alcohols and n-hydrocarbons have been determined down to practically infinite alcohol dilution over a temperature range from 10°C to 45°C. It has been found that (1) the heat of mixing is always negative and that the heat absorption, per mol of alcohol, increases with increasing dilution of the alcohols to a limit of 5800 cal. per mol; that the curves of the molar heat absorption against molar alcohol concentration are identical for all investigated systems—the first four primary n-alcohols in n-hexane and n-heptane. Furthermore, reports in the literature that n-hydrocarbons may be mixed with each other without any heat effect were confirmed.

2. The present experiments and evidence gathered from the literature indicate that (1) primary n-alcohols, in the pure liquid state, are completely associated to double molecules and that when mixed with a hydrocarbon they dissociate into single molecules; (2) that the association takes place between the two hydroxyl groups of two single molecules on account of their electrostatic dipole forces; (3) that the observed heat absorption is entirely due to the dissociation of double molecules, i.e., breaking up of the (electrostatic) hydroxyl bond and that there is no thermal effect of the aliphatic groups in the alcohol molecules upon the hydrocarbon solvent; and (4) that the equilibria between single and double molecules are identical at equal molar concentrations for all primary n-alcohols in all n-hydrocarbons.

3. This theory leads to an equation for the partial vapor pressures of n-alcohols in n-hydrocarbons: log p=log f−(λ−Q)/RT+B−b,where p=the partial vapor pressure at the mol fraction f, λ=the heat of vaporization of pure alcohol, Q=heat of mixing at mol fraction f and temperature T, and b=a universal function of Q. B is determined by the ordinary (simplified) vapor pressure equation log P=−λ/RT+Band is constant over the whole temperature range investigated. λ and B depend upon the nature of the alcohol, while Q and b depend upon molar concentration and temperature.

4. It is shown that after b has been determined once as a function of Q in a specific case, one can calculate partial vapor pressure curves of other systems.

5. An equation has been developed which permits the calculation of the degree of dissociation and therefore Q, for any temperature and concentration.
Dielectric Constant Studies. III. Aqueous Gelatin Solutions
Authors: Ferguson A. L. , Malone J. Gilbert , Case L. O.
Published: November 2004

Measurements have been made of the dielectric constant of gelatin solutions. A test of the Bjerrum ``Zwitter-ionen'' theory was furnished by a study of the effect of pH on the dielectric constant as measured by the Drude method; the data obtained support the theory. Through the application of an equation suggested by Marinesco, an attempt was made to determine the amount of water fixed by gelatin; if this equation is valid for gelatin the results obtained for absorbed water must be interpreted as indicating that the water bound by the gelatin is still free to show its dielectric properties. By means of another equation given by Marinesco relating dielectric absorption with molecular weight, values were calculated for the molecular weight of gelatin; the results obtained are consistent with those given by other methods.
Note on the Structure of the Trithionate Group, (S3O6)—2
Authors: Zachariasen W. H.
Published: November 2004

The structure of the trithionate group is found from a complete determination of the crystal lattice of the potassium compound. Two of the sulphur atoms form four bonds each, three bonds with oxygen atoms and one with sulphur. The four bonds are directed towards the corners of a tetrahedron. The third sulphur atom forms only two bonds, both with sulphur atoms; the bond angle is 103°. The S–O distance is 1.50A and the S–S distance 2.15A. Some features of the binding in sulphur-oxygen radicals are briefly discussed.
The Raman Spectra of Ring Compounds. II. Poly-Substituted Benzene Compounds
Authors: Murray John W. , Andrews Donald H.
Published: November 2004

The Raman spectra of: fluorobenzene, 1,2,4-trichlorobenzene, 1,2,4,5-tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, and hexamethylbenzene have been studied. Their relation to the vibrations of the benzene ring is discussed.
A Relation Between Internuclear Distances and Bond Force Constants
Authors: Badger Richard M.
Published: November 2004

It has been found that for diatomic molecules the relation between the bond force constant, k0, and the internuclear distance, re, is quite accurately given by the expression k0(re—dij)3 = 1.86×105, where dij is a constant depending only on the rows in the periodic table in which the two elements comprising the molecule are located. The expression holds not only for the normal state but for all excited states with a few possible exceptions. Some uses of the relation are discussed and an extension to polyatomic molecules is suggested.
The Partial Pressures of Formic and Acetic Acids above Some Aqueous Solutions; and Their Partial Molal Free Energies at 1.0 Molal Concentration
Authors: Kaye Wm. A. , Parks George S.
Published: November 2004

The paucity of data pertaining to the vapor pressures of aqueous solutions of the organic acids has hitherto retarded thermodynamic calculations in this field. In the present study the partial pressures of formic acid above three of its solutions and those of acetic acid above two solutions have been measured at 25°C. From these results the partial molal free energies at 1.0 molal concentration have then been derived.
Concerning the Structure of N-Alcohol Solutions of Lithium Chloride
Authors: Stewart G. W.
Published: November 2004

Since in x-ray diffraction both experimental results and theoretical considerations are in agreement as to the presence of structure in liquids, an x-ray study is made of concentrated solutions of LiCl in the three normal alcohols, ethyl, propyl and butyl. A definite but tentative conclusion is that in these concentrated solutions of a strong electrolyte, both Li+ and Cl- participate with the molecules of the solvent in forming a common liquid cybotactic or quasi-crystalline structure. This is a new conception which may be made to include what have been described as ``ionic clouds'' and as ``association.'' A conclusion of secondary importance is that the solutions are in fact solutions of the alcoholates of LiCl, although above the corresponding transition temperatures.
The Lattice Energies of the Ammonium Halides and the Proton Affinity of Ammonia
Authors: Bleick Willard E.
Published: November 2004

The lattice energies of NH4F and of the CsCl-type lattices of the other ammonium halides are computed by the method of Born and Mayer, assuming ionic crystals with a van der Waals potential. The calculations appear to be quantitatively satisfactory for the chloride, bromide and iodide. The method fails, however, for the asymmetrical fluoride lattice, and another method is employed. The theoretically calculated lattice energies in kilocalories are, NH4Cl, 161.6; NH4Br, 154.0; NH4I, 145.5. From these lattice energies by means of a thermal cycle the energy change at 0°K of the reaction NH3gas+Hgas+→NH4gas+, which may be called the proton affinity of ammonia, is found to be —206.4 kcal. With this proton affinity and the same cyclic process the lattice energy of NH4F is calculated to be 191.4 kcal.
On Electrolytes in Media of Small Dielectric Constant
Authors: Gross Philipp , Halpern Otto
Published: November 2004

The authors give a general summary of some recent theoretical views concerning the characteristic features of electrolytes in media of small dielectric constant. After a discussion of conductivity observations in water-dioxane mixtures, previous attempts for their theoretical interpretation are criticized. It is shown that in agreement with previously proposed views of the authors the experimental data can be qualitatively and partly quantitatively understood by considering the activity-coefficient arising from ion-dipole interaction. (See preceding paper.)
An X-Ray Study of the n-Aliphatic Alcohols, C10H21OH to C18H37OH
Authors: Wilson Donald A. , Ott Emil
Published: November 2004

An x-ray study of the series of n-aliphatic alcohols C10H21OH to C18H37OH has been made. Spacings along identity periods perpendicular to the 001 planes (c spacings) have been measured at room temperature and at —50°C. By plotting these c spacings against the number of carbon atoms in the chain, it is shown that there are two distinct crystalline modifications, the second appearing only in those members having even numbers of carbon atoms. The common (α) modification is shown to crystallize with the c axis approximately at right angles with the 001 plane while the other (β) has the c axis at an angle of approximately 51° 55′ with the 001 plane. The packing at the ends of the molecules is different in these two modifications. A spectrograph to make such x-ray studies at low temperatures has been designed and constructed. These studies are the foundation of a calculation of the intensities of such c spacing reflections presented in a following paper.
On the Calculation of Intensity Factors for the Powder Method of X-Ray Crystal Analysis
Authors: Blake F. C.
Published: November 2004

In the July issue of Reviews of Modern Physics the writer has surveyed the literature as to intensity factors for the several methods of x-ray analysis. In this survey it was shown that both the atomic form factor F and the temperature factor e—M properly enter into the so-called structure factor. Using the terminology of this survey one can distinguish then between the ``regular'' structure factor S, given by Eq. (51) of the survey, and what is here called the ``reduced'' structure factor S0, given by SFe—M. It is highly important both to the pure physicist and to the industrial physicist to be able properly to get S0 out of S. How this is done is illustrated in this paper both for wurtzite or α-ZnS and for sphalerite or β-ZnS. It was shown in the survey that the reason why it is necessary to operate with the reduced structure factor is on account of the phase differences between the waves diffracted by the several electrons of the same atom, reduced further by the levelling effect of temperature. How these levelling effects are carried out is here shown. On account of the good observational material available for wurtzite the calculations for this are shown first.
The Homogeneous Unimolecular Decomposition of Gaseous Alkyl Nitrites. II. The Decomposition of Ethyl Nitrite
Authors: Steacie E. W. R. , Shaw G. T.
Published: November 2004

The thermal decomposition of gaseous ethyl nitrite is a homogeneous first order reaction. It proceeds at a conveniently measurable rate between 190 and 240°C. The overall reaction is mainly C2H5NO2=NO+12CH3CHO+12C2H5OH.The rate of reaction is given by k=1.39×1014e−37,700/RTsec.−1There is no falling off in rate down to 5 cm pressure. On account of their similarity and simplicity the comparison of the decompositions of methyl and ethyl nitrite is of considerable interest. Further work is in progress on the propyl and butyl nitrites.
On Electrolytes in Media of Low Dielectric Constant
Authors: Fuoss Raymond M. , Kraus Charles A.
Published: November 2004

A conductance function derived by Halpern and Gross is compared with experimental data for what they consider to be the most favorable case: slight dissociation in a solvent of very low dielectric constant, at concentrations near that of the minimum in conductance. Such comparison shows that the functional form required by their equation is not satisfied by the data for tetraisoamylammonium picrate in benzene over the concentration range 1×10—6—2×10—4N. It is pointed out that the Bjerrum radius is not of decisive importance in the interpretation of conductance data.
Raman Spectrum of Carbon Disulphide
Authors: Langseth A. , So/rensen J. Utoft , Nielsen J. Rud
Published: November 2004

The Raman spectrum of liquid carbon disulphide has been investigated with high dispersion. In addition to the lines already known, five very faint lines have been observed. The intensities of the stronger lines were measured and, with a spectrograph of low dispersion, the degrees of depolarization of the two principal bands were determined. The results are in accord with the assumption made by Fermi, Dennison and Placzek that large perturbations of some of the energy levels occur on account of the approximate coincidence of v1 with 2v2. The values Δ = —120 cm—1 and |P| = 17.8 cm—1 are obtained for the difference Δ = v1 — 2v2 and for the coupling constant P = βh½/4π2μ1½μ 2(v1+2v2)32.
Molecular Symmetry and the Reduction of the Secular Equation. Part II
Authors: Stearn Allen E. , Lindsley Charles H. , Eyring Henry
Published: November 2004

Symmetry is used to reduce exactly the secular equation for nine monovalent atoms forming a body-centered cube from an equation of forty-second degree to equations of third degree and lower. Application of the results is then made to calculate approximately the energy of the isolated unit cell for sodium. The vector method recently put forward by Van Vleck is shown to be a valuable check on such calculations.
The Degeneracy, Selection Rules, and Other Properties of the Normal Vibrations of Certain Polyatomic Molecules
Authors: Wilson E. Bright
Published: November 2004

The number, degeneracies, and symmetries of the normal modes of vibration are given for molecules in which several atoms are bonded to a central atom. Ninety-nine symmetries, including all possible structures with three to seven atoms and the more important structures of eight and nine atoms are listed in tables. The selection rules for the Raman and infrared spectra are included as well as the polarization properties of the Raman lines and the rotational structure of the vibrational bands. In a number of more important cases figures are given showing the normal modes of vibration. Many examples of molecules which are believed to possess certain of the structures are included in the tables, together with references to experimental papers dealing with them.
Wave-Mechanical Treatment of the Naphthalene Molecule
Authors: Sherman J.
Published: November 2004

The secular equation corresponding to the forty-two canonical structures for naphthalene has been set up and solved rigorously (except for the neglect of certain exchange integrals), the energy value obtained being 2.0400α greater than that corresponding to one of the unexcited structures, in which α is the single exchange integral between adjacent carbon atoms. The equation has also been solved by various simplified procedures, and it has been found that the assumptions made in the earlier treatment of Pauling and Wheland are to a considerable extent justified. The coefficients of the various structures in the wave function for the normal state have been evaluated. It has been found that of the three unexcited structures the symmetrical one makes approximately a 50 percent greater contribution to the wave function than either of the two unsymmetrical structures. Some further discussion of the magnitudes of the coefficients is given.
The Disposition of Work Energy Applied to Crystals
Authors: Maier C. G. , Anderson C. T.
Published: November 2004

The experiments described in this paper were initiated for the purely practical purpose of securing data to be used for an energy balance of the process of comminution of solids. The technologic problem is not considered here but rather the antecedent fundamental and scientific one of attempting to describe the thermodynamic properties of crystals as a function of particle size. It has been customary to ascribe observable variations in the properties of crystalline materials of large or fine particle size to a change of free energy, entropy or heat content resultant from the subdivision. Consideration of the first law of thermodynamics with reference to the application of work energy to crystals allows for only two obvious possibilities: (1) The heat produced in the crystals by the applied work is equal to it, whence no change of intrinsic energy of the material can occur; or (2) part only of the work appears as heat and the intrinsic energy of the crystals must increase. In this latter case, it is supposed that the energy corresponding to the increase of intrinsic energy is ``stored'' in the surficial layers of the crystal particles. We shall offer no apology for approaching the problem of testing these alternatives in a strictly empirical manner and for presenting data which may seem to contradict much of previous theory and experiment concerning the ``surface energy'' of solids. However tempting a review and criticism of previous attempts to measure or theoretically define this quantity might be, the elementary approach represented by our work now seems essential for understanding of the anomalous results, both of ourselves and others. Experimental test based on the first law, as expressed above, obviously could be either by (1) attempting to determine the change of intrinsic energy of fine compared to coarse particles of suitable materials or (2) by comparing the work and heat during the comminution process. Both of these experimental alternatives are described below. Thus we shall first describe experiments upon the heat of solution of fine and coarse calcite, designed to reveal measurable differences of intrinsic energy due to comminution. Further, we have investigated the specific heat at low temperatures of similar samples of calcite, and later of finely drawn wires of copper and aluminum in the annealed compared to the cold-worked state, referring to that part of the intrinsic energy represented by heat content. Finally, in the case of copper and aluminum, we have adopted the second experimental alternative of comparing the work and heat during a drawing process.
X-Ray Diffraction Study of Carbon Black
Authors: Warren B. E.
Published: November 2004

X-ray diffraction patterns of carbon black have been made with strictly monochromatic radiation. Without making any assumptions as to the crystallinity of the material, the distribution of atoms about any one atom has been determined directly from the experimental scattering curve by the method of Fourier integral analysis. The results indicate definitely the existence of single graphite layers. Whether these layers have definite orientation and position with respect to one another (graphite crystal) or whether carbon black is a mesomorphic form of carbon, cannot be definitely decided from the experimental results. It is probable that carbon black is a heterogeneous mixture of particles which range from single graphite layers up to graphite crystals several layers thick. The intense small angle scattering is due to the difference between grain density and average density, caused by the loose packing of the extremely small grains.
The Reduction of Oxygen to Hydrogen Peroxide by the Irradiation of Its Aqueous Solution with X-Rays
Authors: Fricke Hugo
Published: November 2004

Irradiation with x-rays produces no chemical change in air-free water. With oxygen present, hydrogen peroxide is formed due to a primary activation of the water. The initial production of hydrogen peroxide is independent of the oxygen pressure, from 4 to 70 cm Hg and is dependent on the hydrogen ion concentration according to: H2O21000r×1000 cc=[2.2+2.2[109.6−pH1+109.6−pH]10−6N.
The Decomposition of Nitrous Oxide on the Surface of Platinum. I. The Retarding Effect of Oxygen
Authors: Steacie E. W. R. , McCubbin J. W.
Published: November 2004

An investigation has been made of the decomposition of nitrous oxide on the surface of spongy platinum in the temperature range 485 to 570°C. The results are in agreement with the previous work of Hinshelwood, Schwab and others using filament catalysts. Experiments have also been made on the effect of added oxygen. It is found that oxygen formed in the reaction has a much larger retarding effect than has added oxygen. Under certain circumstances oxygen and nitrogen also retard the reaction by hindering diffusion to the more remote parts of the catalyst. It is concluded that oxygen formed in the reaction is adsorbed in the atomic condition, while added oxygen is mainly adsorbed in the form of molecules.
Studies on Glass. XI. Some Thermodynamic Relations of Glassy and Alpha-Crystalline Glucose
Authors: Parks George S. , Snyder Loilor J. , Cattoir Francis R.
Published: November 2004

Although the properties of a glass depend to some extent upon its thermal history, the view is expressed that fairly satisfactory thermodynamic data can be obtained for well-annealed glasses. In the present study the difference between the heat contents of glucose glass and α-crystals has been determined calorimetrically at 20°C and with the aid of this result the corresponding differences in entropy and free energy have also been computed. The value for this last quantity is ΔF°293 = 1670 cal. per mol. Solubility measurements have been made for glucose α-crystals and glass in methyl, ethyl and isopropyl alcohols at 20°. The free energy values thereby obtained for the conversion of α-crystals into glassy glucose are in good agreement with the preceding value derived from the thermal data.
On the Theory of Free Radicals and Organo-Alkali Compounds
Authors: Nilsen Bailli
Published: November 2004

The theory of the free radicals of Pauling and Wheland is applied to the electron affinities of the radicals. The results are compared with the measurements of Bent, and they indicate that the charging electron enters in resonance with the whole system of [p]h-electrons. The theory is generalized to unsaturated hydrocarbon radicals and it is shown that the formation of ionizable metal derivatives is due to the resonance between the charging electron and the [p]h-electrons. Some cases of anomalous reactions of organo-alkali compounds are also interpreted.
The Compressibility of Solutions of Three Amino Acids
Authors: Bridgman P. W. , Dow R. B.
Published: November 2004

The compressibility of aqueous solutions of glycine, α-amino butyric acid, and ε-amino caproic acid have been measured over the concentration range up to 2.5 N at 25° and 75°C and up to a maximum pressure of 8000 kg/cm2. The results are exhibited in tables giving the volume in cm3 as a function of pressure, temperature, and concentration of that amount of solution which contains one gram of water, and in figures showing the apparent molal volume at 25° as a function of pressure and concentration. The general character of the results is complicated; the most striking result is that at low pressures the apparent compressibility of the acid in solution is positive, which is opposite in sign from all other known solutes. A connection is probable with the high dielectric constant. Other qualitative aspects of the phenomena are discussed.
The Green Flame of Phosphorus Hydride
Authors: Ludlam E. B.
Published: November 2004

The rotational structure of the bands in the green flame of phosphorus indicates that the emitting molecule is PH.
The Thermal Equilibrium Between Ethylene Iodide, Ethylene and Iodine
Authors: Cuthbertson G. R. , Kistiakowsky G. B.
Published: November 2004

The thermal equilibrium between ethylene iodide, ethylene and iodine in the vapor state has been studied in the temperature range 50 to 125°C. The method devised involved measurements of the iodine vapor pressure by a photometric device utilizing photronic cells in a null-point arrangement. Iodine and ethylene iodide were both present as unsaturated vapors. The measurements gave results which were found to agree with the extrapolation of Mooney and Ludlam's data for lower temperatures, but to disagree with the same authors' higher temperature determinations. The heat of dissociation of ethylene iodide is 13.4±0.5 kcal. The position of equilibrium is given by: log K = — 13,400/4.58T+8.17, where the equilibrium constant is expressed in atmospheres as units.
The Reaction Rate of Acetic Anhydride and Water
Authors: Plyler E. K. , Barr E. S.
Published: November 2004

The infrared absorption of acetic acid and acetic anhydride has been measured from 1μ to 6.5μ. A number of bands were observed below 5μ which were similar for the two substances, and were attributed to CH bonds. An intense band was found in acetic anhydride at 5.45μ and in acetic acid at 5.75μ. By measuring the intensity of these bands at different times, the reaction velocities of equivalent amounts of anhydride and water were determined. This method offers a new and independent means of determining reaction velocities and related constants. The reaction was approximately unimolecular for any concentration. The reaction constant decreased as the time increased. A different value of the constant was obtained when different concentrations were used. The reaction constant was also determined for three different temperatures. The values of the reaction constant and other constants are tabulated. The error is estimated to be 10 percent.
Products and Processes of Ionization in Methyl Chloride as Determined by a Mass Spectrometer
Authors: Bauer S. H. , Hogness T. R.
Published: November 2004

The following ions were found to be produced in methyl chloride as primary products: CH3Cl+,CH3+,CCl+,CH2+,Cl+,HCl+,CH+ and C+ —listed in order of decreasing intensity. Small concentrations of the H+ ion were also detected. This latter peak was not investigated completely. The appearance potentials for the CH3Cl+, CH3+ and Cl+ ions are 11.0, 14.7 and 26 volts, respectively.
Electronic Structures of Molecules XIV. Linear Triatomic Molecules, Especially Carbon Dioxide
Authors: Mulliken Robert S.
Published: November 2004

Electron configurations of the triatomic linear molecules CO2, BO2—, N2O, CS2, COS, NO2+, N3—, NCO—, NCS—, BeF2, HgCl2, ClCN, ClBO, etc. are given. The electron configurations probably of all of these are formally analogous, or formally identical in the case of isoelectronic molecules, such as CO2, N2O, BeF2, etc. The BeH2 type is also touched on. The relations of the electron configurations to ordinary valence conceptions are discussed, and the importance in practice of cases intermediate between those represented by simple valence formulas is emphasized. The usefulness of the present method in giving a simple description of intermediate cases of all sorts (between double-bonded A=B=C and single-bonded A–B–C, between homopolar A–B–C, etc., and heteropolar A—B++C—, etc., between A–B≡C and A+=B=C—, etc.) is brought out. The ionization potentials of CO2, CS2, N2O, HgCl2 are interpreted in relation to their electron configurations. The minimum potentials of CO2, of CS2, and of HgCl2, respectively, correspond to removal of a nearly nonbonding pπ electron of the O, S, or Cl atom. It is shown that the ultraviolet emission bands of CO2 probably represent transitions among four electron states of CO2+ which correspond to the four lowest ionization potentials of CO2; if this interpretation of the bands is correct, the CO2+ molecule has a linear form in these states. According to this interpretation, the four lowest potentials of CO2 are probably 13.72, 17.09, 18.00, and about 21.5 volts (or perhaps 14.63, 18.00, 18.91, and about 22.4 volts). These values are based on identification of the CO2 Rydberg absorption series limit at 18.00 volts with one of the potentials. The minimum potential above obtained (13.72 or perhaps 14.63 volts) differs considerably from the accepted value 14.3 or 14.4 volts based on electron impact. Radicals N3, NCO, NCS, and molecules NO2 and others are also touched on. A reason for the triangular form of NO2 is found in the fact that linear NO2+ (like CO2 or N2 or NO+) is composed of a stable system of closed shells, while the final electron added to make neutral linear NO2 would have to go into a probably fairly high energy antibonding orbital (as in NO). Evidently the actual NO2 avoids this by being triangular. Ultraviolet absorption spectra of CO2, CS2, and COS are also considered.
The Crystal Structure of Hexagonal Silver Iodide
Authors: Helmholz Lindsay
Published: November 2004

On the basis of oscillation data a structure has been assigned to hexagonal silver iodide at room temperature in which the silver atoms are distributed at random among four positions tetrahedrally surrounding the ideal position in the wurtzite structure. Previous work is discussed and evidence supporting the preference of this structure is presented. At liquid-air temperatures the structure is found to approximate closely that of wurtzite with the ideal parameter value of 1/8. Physical characteristics of silver iodide are discussed in relation to the proposed structure.
A Study of the Molecular Structure of Diiodoethane Iodine Bond Resonance and the Molecular Structure of Diiodoethylene. Molecular Packing in Their Crystal Lattices
Authors: Klug Harold P.
Published: November 2004

Using data from an x-ray study of the crystal structure of sym-diiodoethane and sym-diiodoethylene (trans form) the positions of the iodine atoms in the crystal cells were located. Iodine bond resonance is discussed and a factor of 0.92 of the length of the longer bond proposed for evaluating the interatomic distance for any resonating bond. On the basis of the concepts of tetrahedral carbon bonds, bond resonance, Pauling's normal convalent bond radii, etc., reasonable molecular models for the above substances were predicted. Comparison of these with the x-ray data showed the iodine-iodine distances to be in excellent agreement with certain iodine-iodine distances within the crystal cells, thus locating the molecules within the cells. These models together with Mack's concept of the atomic domain radius of atoms in crystals permitted a consideration of the packing of the molecules in the crystal lattice, thus locating the atomic coordinates of the carbon and hydrogen atoms in the cell. The domain radii found were; iodine = 1.97A, and hydrogen = 1.23A. The resulting molecular packing is seen to explain and be in excellent agreement with observed physical properties of the two crystals.
The Raman Spectra of the Isotopic Molecules H2, HD, and D2
Authors: Teal Gordon K. , MacWood George E.
Published: November 2004

The Raman spectra of H2, HD and D2 gases, at 3 atmospheres pressure, were excited by Hg 2537 and photographed with a high dispersion quartz prism spectrograph. A total of 42 lines were analyzed. The positions of the pure rotation lines for H2 agree with the measurements of Rasetti but the lines in the Q vibration band do not. New vibrational constants calculated from the Raman and emission spectrum data of H2 and HD give calculated values of the positions of the rotational-vibration Raman lines in good agreement with the values observed for the three isotopic molecules. Contrary to the theoretical predictions, the 0,0 line of the Q vibrational band of HD was observed. A source of error in Raman measurements, namely, the movement of the spectrum due to variations of the barometric pressure during the exposure of a plate, was detected and eliminated.
On the Possibility of a Metallic Modification of Hydrogen
Authors: Wigner E. , Huntington H. B.
Published: November 2004

Any lattice in which the hydrogen atoms would be translationally identical (Bravais lattice) would have metallic properties. In the present paper the energy of a body-centered lattice of hydrogen is calculated as a function of the lattice constant. This energy is shown to assume its minimum value for a lattice constant which corresponds to a density many times higher than that of the ordinary, molecular lattice of solid hydrogen. This minimum—though negative—is much higher than that of the molecular form. The body-centered modification of hydrogen cannot be obtained with the present pressures, nor can the other simple metallic lattices. The chances are better, perhaps, for intermediate, layer-like lattices.
The Molecular Structures of Sulfur Dioxide, Carbon Disulfide, and Carbonyl Sulfide
Authors: Cross Paul C. , Brockway L. O.
Published: November 2004

The structures of the molecules SO2, CS2, and COS have been investigated by the electron diffraction method with the following results; SO2, S – O = 1.46±0.02A; CS2, C – S = 1.54±0.03A; COS, C – O = 1.16±0.02A, C – S = 1.56±0.03A. The types of bond arrangement compatible with these interatomic distances are discussed. In SO2 the molecule resonates between the structures having single-double and double-single bonds between the sulfur and the two oxygen atoms, with a bond angle of 122°±5°. CS2 is a linear molecule with the structure having the two double bonds predominating over those having a single and a triple bond. In COS the double-double bond arrangement and the structure having the triple carbon-oxygen bond predominate.
Thermodynamic Properties of Sulfur Compounds II. Sulfur Dioxide, Carbon Disulfide, and Carbonyl Sulfide
Authors: Cross Paul C.
Published: November 2004

The thermodynamic properties of sulfur dioxide, carbon disulfide, and carbonyl sulfide are calculated from the molecular constants obtained by electron diffraction and Raman and infrared spectra. — (F0 — E00) / T298.1 = 50.95, 48.28, 47.39; S0298.1 = 59.40, 56.84, 55.34 for SO2, CS2(g), and COS, respectively. The results are applied to several reactions involving these compounds. The free energies of formation of CS2(l) and COS at 298.1°K are +15.24 and —40.48 kg.cal.
The Energies of Hydrocarbon Molecules
Authors: Serber Robert
Published: November 2004

The energies of a number of hydrocarbon molecules have been calculated by the Heitler-London-Pauling-Slater method with two objects in view, first, to see if this simple theory leads to the correct energies of formation, and second, to determine what significance can be attached to the empirical additivity rule for bond energies. Our equations involve three parameters, which roughly speaking, determine the gross energies of a C–H bond, a C–C bond, and a C=C bond. These have been evaluated from the observed energies of methane, ethane and ethylene. The energies calculated for other hydrocarbons then agree surprisingly well with the observed values. Nevertheless, the validity of an empirical bond additivity rule seems to be purely fortuitous. The calculations further indicate that the theoretical significance ordinarily ascribed to the so-called ``observed resonance energies'' is a very questionable one.
The Relation Between Vector and Bond Eigenfunction Methods for Spin Degeneracy
Authors: Bear Richard S. , Eyring Henry
Published: November 2004

A method previously developed for the calculation of matrix components for problems in which spin degeneracy only is important is shown to be equivalent to an operator method derivable from the vector approach of Dirac. Complete rules for the simple construction of matrices for all possible cases which can arise under these conditions of spin degeneracy are given. An especially simple way of determining secular equations for states of the identical representation is described, and the method is applied to the calculation of the energy of an infinite linear extension of sodium atoms. An inspection method of resolving a crossed six bond eigenfunction in terms of the uncrossed set is given.
Active Hydrogen
Authors: Grubb A. C. , Van Cleave A. B.
Published: November 2004

Dry hydrogen can be activated in an electric discharge if the pressure and voltage are carefully regulated. Active hydrogen reduces metallic sulphides whose heat of formation is 22,000 cal. or less. The active gas is decomposed by 3 cm of well packed glass wool. A quantitative method is given for the determination of active hydrogen. Less of the active gas is formed in a tube coated with stearic acid or phosphoric acid than when no coating is employed. The decay reaction was found to follow the expression for a unimolecular reaction. The rate of decay appears to be independent of the wall surface. The period of half-life at room temperature and 40 mm pressure is 0.2 sec. approximately. The energy of formation of active hydrogen is approximately 18,000 cal. The energy of activation for the decay of the active constituent is approximately 17,800 cal. The properties of active hydrogen are considered in relation to the properties predicted for H3.
Triatomic Ions in Mixtures of the Hydrogen Isotopes
Authors: Luhr Overton
Published: November 2004

A mass spectrograph analysis has been made of aged ions in mixtures of hydrogen and deuterium. The concentration of deuterium was varied from 84 percent to less than one percent. After drifting through 5 cm of gas at about 0.5 mm pressure, the ions were found to be over 95 percent triatomic; that is, H3+, H2D+, HD2+ and D3+. Measurement of the relative intensities of the triatomic ion peaks indicates a slightly greater number of H3+ and D3+ ions compared to H2D+ and HḊ2+ than would be expected from probability considerations if the H and D atoms behaved exactly alike. This tendency for like atoms to group together may be accounted for by taking cognizance of the proper equilibrium constant for the different types of diatomic molecules in the gas mixtures employed. There is no evidence of further preferential grouping in the formation of the triatomic ions from the primary molecular ions. The relative heights of the triatomic ion peaks may be used to determine the abundance of the isotopes in a sample of gas.
The Resolution of Bond Eigenfunctions in Terms of a Linearly Independent Set
Authors: Eyring Henry , Gershinowitz Harold
Published: November 2004

By means of simple operators derived from the antisymmetrical configuration eigenfunctions a method is devised for obtaining the coefficients in the expansion of a bond eigenfunction in terms of a linearly independent set. This method eliminates any necessity of drawing diagrams and removes the unique advantage of the uncrossed set. It is applied to the determination of the coefficients of eigenfunctions expanded in terms of the Rumer (uncrossed) set for as many as six bonds. For three and four bonds crossed sets are given for which the process of resolving eigenfunctions is simpler than for the Rumer set. A convenient method of expansion in terms of the Rumer set is extended to include eigenfunctions of as many as six bonds of any multiplicity.
Dielectric Constant Studies V. Anomalous Dispersion of Lecithin in Viscous Mineral Oils
Authors: Ferguson A. L. , Case L. O. , Evans G. Harlowe
Published: November 2004

A unique receiver and accompanying cell for determining dielectric constants by the resonance method were constructed. Their design is such as to reduce to a minimum several types of error inherent in the resonance method. Dielectric constant measurements were made on five solutions of lecithin in very viscous mineral oils at three temperatures and at six wavelengths. Three distinct methods were employed: (1) refractometer method—frequency of D line of sodium, (2) resonance method—32.8 m, 94 m, 320 m, 1308 m, (3) bridge method—precision Wheatstone bridge, 1036 cycles. Analyses of the experimental curves and comparisons with theoretical Debye curves definitely indicate dispersion though not of a simple type. Another series of measurements made on one solution at 16 different wavelengths covering the range from 40 m to 5,000,000 m still failed to show any individual simple dispersion regions. A qualitative explanation based on varying viscosities of the components of the solvent, the presence of polar radicals in the solute molecules, and the extensive association of the solute is offered.
The Moles of Vibration of Butane and Pentane. ``Free Rotation'' about Carbon-Carbon Bonds and a New Type of Stereoisomerism
Authors: Kassel Louis S.
Published: November 2004

The Hamiltonian function for a chain of four carbon atoms with the simple valence force system potential energy is transformed by successive changes of variables to such a form that the wave equation is nearly separable into five harmonic oscillator equations and a sixth equation governing the internal rotation. This rotation equation has been solved numerically for twelve different rotational levels of the nonvibrating molecule, some of which actually correspond to rotations, others to a torsional oscillation of restricted amplitude about either the cis or the trans position. The remaining terms in the wave equation are treated as a perturbation; the first-order perturbation energy is less than 1 cm-1 for all moderately low vibrational states. There are thus two isomeric forms of butane with plane carbon skeletons, and a third form in which the two ethyl groups are rotating about the central carbon-carbon bond. The vibration frequencies for the three possible plane forms of a five-carbon chain have been calculated. When the frequencies of C2, C3, C4 and C5 are calculated with the same two force constants throughout, and by taking account of the two plane forms of C4 and the three of C5, results are obtained in fair statistical agreement with observed Raman and infrared lines.
The Homogeneous Unimolecular Decomposition of Gaseous Alkyl Nitrites III. The Decomposition of n-Propyl Nitrite
Authors: Steacie E. W. R. , Shaw G. T.
Published: November 2004

The thermal decomposition of n-propyl nitrite is a homogeneous first order reaction in the temperature range 170 to 210°C. The mechanism of the decomposition is analogous to those of the other alkyl nitrites, viz., C3H7ONO→NO+12C2H5CHO+12C3H7OH.The rate of reaction is given by K=2.75×1014e−37650/RT ·sec.−1.The rates and activation energies of the various nitrite decompositions are compared. It is concluded that the increase in rate with the higher members of the homologous series is probably due to the participation of extra vibrational degrees of freedom. An estimate of the strength of the —O–N— bond is made.
The Constancy of Two Dipole Moments in the Vapor State and Their Apparent Variation in Solution
Authors: Smyth C. P. , McAlpine K. B.
Published: November 2004

The validity of the solution method for the determination of dipole moment is considered with particular reference to the possible variation of moment with temperature. The moments of heptyl bromide and butyl chloride in the vapor state are found to be 2.07±0.05 and 2.04±0.01, respectively, which show the absence of appreciable increase in moment in the normal alkyl chlorides and bromides with increase in the length of the carbon chain beyond ethyl. Consideration of these values together with data for the alkyl halides in solution leads to the following estimated moment values for the vapor state: n-propyl bromide and n-butyl bromide, 2.04±0.03; n-propyl iodide and n-butyl iodide, 1.93±0.04.