摘要:

Ozone yields have been measured in CO2–O2mixtures irradiated with single pulses from a Febetron 705 at a dose rate of 1026 eV g−1s−1. Low concentrations of carbon dioxide in oxygen rapidly reduce the yield fromG(O3) = 12.8 toG(O3) ≈ 9. At 300 Torr total pressure, as the oxygen concentration is reduced, the ozone yield decreases from this yield ofG(O3) ≈ 9 to an extrapolated yield, at zero oxygen, of close toG(O3) = 7.8. Changes of yields with composition are explained in terms of ionic reactions, the main neutralization process beingAt 700–1500 Torr total pressure, the ozone yields are lower than that at 300 Torr. It is proposed that clustering of the ionic species affects the products of the neutralization reaction.Sulfur hexafluoride suppresses the dissociative neutralization reaction and ozone yields from mixtures containing 1.5–2% SF6are those predicted from direct neutral dissociation processes in the pure gases.Computer calculations are used to compare the experimental results to the proposed mechanism and, in general, a good fit is obtai

ISSN:0008-4042    

DOI:10.1139/v70-580

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The infrared absorption of the products from electrically dissociated H2O or D2O vapor and other hydrogen–oxygen systems trapped at liquid nitrogen temperature was measured between 4000 and 300 cm−1. Four new absorption bands were found in the deuterated systems at 857, 820, 760, and about 440 cm−1. By isotopic substitution of18O the frequencies are shifted to 806, 775, 717, and ~420 cm−1as expected for O—O vibrations. In the hydrogen systems this region is obscured by the strong libration bands of H2O and H2O2molecules. Temperature and composition effects show that more than one new species is involved. Accordingly the new spectra are assigned to the often postulated polyoxides, H2O3and H2O4, stabilized in the water–peroxide matrix. The more abundant, and also more stable, H2O3has a half-life of some 5 h at −65 °C.The observed frequencies are consistent with zigzag chain structures linked by single covalent bonds as in hydrogen polysulfides. Relative concentrations of the polyoxides are estimated at 5 to 10 mole% depending on the composition of the starting material. Possible mechanisms of formation and decomposition are discussed.

ISSN:0008-4042    

DOI:10.1139/v70-581

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The phase diagram of the RbCl–NaCl system has been measured by the method of cooling curves. By combining these data with available thermochemical data for the system, the integral molar excess free energy of mixing at 800 °C has been calculated as ΔGE = −632XRbClXNaCl cal/mole; and the integral molar excess entropy of mixing has been calculated as ΔSE = −0.208XRbClXNaCl cal/°K mole. Estimated precisions are ±50 cal for ΔGEand ±0.05 cal/°K mole for ΔSEatXRbCl = XNaCl = 0.5.

ISSN:0008-4042    

DOI:10.1139/v70-582

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Kinetics of BrO decomposition was studied between 293 and 673 °K using the technique of kinetic spectroscopy. At 293 °K the reaction rate is second order with respect to BrO and is independent of [Br2], [O2], and total pressure of diluent gas. The activation energy for decomposition obtained from rate measurements between 293 and 450 °K is 0.65 ± 0.05 kcal/mole. Above 450 °K this activation energy appears to increase to 4.5 kcal/mole. It is shown that, although kinetically the ClO and BrO decompositions are similar, the mechanism for BrO decomposition below 450 °K is much simpler than that of ClO. The reaction proceeds, most likely, via one step: 2 BrO → 2 Br + O2, with Br2O2being an activated complex, which has either linear or staggered configuration. ClO and BrO decomposition is compared withreaction.

ISSN:0008-4042    

DOI:10.1139/v70-583

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The aqueous solubility of the system silver selenide has been investigated in an inert atmosphere of nitrogen at a unit molar ionic strength and constant temperature of 25° C. The experimental evidence indicates the formation of two aqueous species [Ag2(HSe)(OH)], and [Ag(Se)2(OH)]4−in contact with the precipitated selenide in different regions of acidity. The former exists in acidic medium and has a pβ value of 48.49 ± 0.10 while the latter is stable only in alkaline conditions and has a pβ value of 24.07 ± 0.19. A mathematical treatment has been elaborated to identify and calculate the stability constants of such selenide complexes formed through a heterogeneous equilibrium.

ISSN:0008-4042    

DOI:10.1139/v70-584

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Starting from the approximations of the i.n.d.o.-l.c.a.o.-s.c.f. method and using approximate Hartree–Fock perturbation theory, a method has been developed whereby the nuclear shielding of a nucleus for a first row element may be estimated. The method avoids the use of the average energy approximation. The method is demonstrated by calculating the19F chemical shifts in the first row binary fluorides relative to the fluorine molecule.

ISSN:0008-4042    

DOI:10.1139/v70-585

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The chemical shifts of the14N nucleus in a number of nitrogen–halogen–oxygen compounds have been estimated within the framework of the i.n.d.o.-l.c.a.o.-s.c.f. method using approximate perturbed Hartree–Fock theory. Generally good agreement with experiment is achieved. The calculations indicate that the variation in14N chemical shift is due to either changes in orbital angular momentum, or to the presence of low lying excited states, or to a combination of both effects.

ISSN:0008-4042    

DOI:10.1139/v70-586

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

The thermal analyses of copper basic oxysalts of the type Cu2(OH)2XOy, where X = S, C, Cl, Br, I, N, HC andy = 4, 3, or 2 reveal that decomposition occurs, in most cases, by dehydroxylation with concomitant disproportionation of the oxysalt. An outstanding exception to this pattern of decomposition is the basic sulfate. Calorimetric measurements along with related enthalpic values for the decomposition reaction are given.The kinetics of thermal decomposition of the compounds are classified into three main categories: (i) three-dimensional contracting sphere model, (ii) first-order rate, and (iii) nucleation controlled rate processes.The infrared spectral data of nine copper basic oxycompounds in the frequency region 4000–250 cm−1are presented with their assignments. The fundamental infrared inactive modes of the anionic species SO42−, NO3−, etc. become active by the presence of the copper hydroxide ligand indicating a lowering of symmetry in the anion.

ISSN:0008-4042    

DOI:10.1139/v70-587

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Characterization was made on the sulfonated polyphthalamide microcapsules (SPPAM) prepared by making use of the interfacial polycondensation reaction ofp-phthaloyl dichloride with mixtures of 4,4′-diaminostilbene-2,2′-disulfonic acid and diethylenediamine of varying mole ratios. The specific conductance of dialyzed dispersions of the H form of SPPAM in water was always higher than that of Na form microcapsule dispersions.On the other hand, the former dispersions invariably gave a much lower pHin comparison with the latter. Cation binding experiments established increasing orders, Ca2+ < Sr2+ < Ba2+and Li+ < K+, NH4+, Na+ < Cs+, for the binding of di-and monovalent cations to SPPAM, respectively. The results were interpreted as showing that less hydrated ions are easier to adsorb on the negatively charged microcapsules. Finally, the feasibility of using SPPAM as ion-exchanger was indicated.

ISSN:0008-4042    

DOI:10.1139/v70-588

出版商:NRC Research Press    

年代:1970

数据来源: NRC

摘要:

Reaction of 1,10-phenanthroline (phen) with gallium trihalides yields the complexes GaX3(phen) (X = Cl, Br, I), GaX3(phen)2(X = Cl, Br), and GaX3(phen)3(X = Br, I). Raman and infrared measurements have established the structures of these compounds as [GaX2(phen)2][GaX4], [GaX2(phen)2]X, and [Ga(phen)3]X3. GaI3(bipy) (bipy = 2,2′-bipyridyl) has the structure [GaI2(bipy)2][GaI4]. Raman and far-infrared measurements allow ready identification of GaX4−ions in these systems. The stereochemistry of the cation [GaX2(phen)2]+cannot be established from vibrational data alone.

ISSN:0008-4042    

DOI:10.1139/v70-589

出版商:NRC Research Press    

年代:1970

数据来源: NRC