摘要:

The reaction between methylacetylene and hydrogen over supported and unsupported nickel catalysts has been investigated in a static constant volume system for a wide range of temperature and reactant ratios. The pressure–time curves consist of two linear portions of different slopes. The reaction over nickel is largely simple hydrogenation, the early stages being principally a selective production of propylene with small yields of reduced polymers of methylacetylene. The orders of the hydrogenation reaction are first and zero with respect to hydrogen and methylacetylene respectively. The overall apparent activation energies for nickel–pumice and nickel–kieselguhr are 16.8 and 14.0 kcal/mole and for unsupported nickel catalysts vary between 17.2 and 20.0 kcal/mole. A satisfactory "compensation effect" exists between the activation energies and logarithmic values of the pre-exponential factors. The unsupported catalysts were not poisoned when methylacetylene was added first to the reaction vessel.

ISSN:0008-4042    

DOI:10.1139/v67-173

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v67-174

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The velocity of sound in liquid CF4has been measured in the temperature range from its triple point to its normal boiling point. Measurements have been made with an ultrasonic interferometer, consisting of barium titanate ceramic in tubular form, to an accuracy of 0.4% or better. The adiabatic compressibility has also been calculated for the corresponding temperature range using available density data. No other velocity of sound or compressibility data for CF4are available for comparison. Comparisons with other liquids by the method of corresponding states show similarity between CF4and CCl4, but not between CF4and methane or argon.

ISSN:0008-4042    

DOI:10.1139/v67-175

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The reaction of carbon dioxide with water and hydroxide ions has been studied by measuring the rate of oxygen exchange between sodium carbonate and bicarbonate and oxygen-18 enriched water as a function of pH, ionic strength, and carbonate–bicarbonate concentration. It has been shown that these reactions are catalyzed by carbonate and bicarbonate ions. Rate constants for the uncatalyzed and catalyzed reactions have been evaluated.

ISSN:0008-4042    

DOI:10.1139/v67-176

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The systems Co(NCS)2– methanol vapor and Co(NCS)2– ethanol vapor have been studied. The known dialcoholates and also two previously unreported tetraalcoholates, were prepared. The dissociation pressures of the alcoholates were measured at several temperatures. Values of ΔH0and ΔS0at 25 °C were calculated for the reaction Co(NCS)2+nROH = Co(ROH)n(NCS)2, withn = 2 and 4. Monoalcoholates were not found. A metastable system dialcoholate plus viscous blue liquid is discussed.

ISSN:0008-4042    

DOI:10.1139/v67-177

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

Transition metal complexes of a number of 1-substituted tetrazoline-5-thiones have been prepared and their infrared spectra examined in the 3 600 – 500 cm−1region. The analytical applications of 1-substituted tetrazoline-5-thiones for the gravimetric determination of cadmium and palladium have been studied.

ISSN:0008-4042    

DOI:10.1139/v67-178

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v67-179

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

An unmodified model 301 Mechrolab osmometer is used to determine the molecular weight of a series of polyvinylacetate polymers of relatively low degrees of polymerization in acetone, benzene, carbon tetrachloride, chloroform, and methanol. Anomalous results were obtained with chloroform. The solute–solvent parameter μ1and molecular weight are calculated with the Flory–Huggins theoretical equation.

ISSN:0008-4042    

DOI:10.1139/v67-180

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The unusual features of the proton and19F nuclear magnetic resonance spectra of (CH3)3SnCF2CFHCF3, arising from the asymmetry about the β-carbon atom, are discussed in terms of the molecular stereochemistry. Data for (CH3)3SnCF2CF(CF3)Sn(CH3)3, (CH3)3SnCF2CF2H, and (CH3)3SnCF2(CF2)2CF2H are also presented.

ISSN:0008-4042    

DOI:10.1139/v67-181

出版商:NRC Research Press    

年代:1967

数据来源: NRC

摘要:

The preparation and proton resonance spectra of the 1-iodopropenes are reported and solvent effects on the proton spectra of the chloro-, bromo-, and iodo-compounds are measured. The proton coupling constants are discussed in terms of old and new electronegativity correlations. The olefiniccisandtransproton shifts can be attributed mainly to a paramagnetic contribution from the substituent, whereas thegemolefinic proton shifts depend in addition on the electron-withdrawing power of the substituent. The methyl proton shifts in the 1-substituted compound show little dependence on the substituent and this is discussed in relation to the barrier heights to methyl rotation. The solvent shifts in benzene cannot be completely reconciled with a dipole – induced dipole model. They increase with the size of the substituent and are largest for protons farthest from the substituent. The solvent shifts in acetone can be explained as due to weak hydrogen bonding and reaction field effects. The shifts of protonsgemto the substituent arise mainly from hydrogen bonding, whereas the shifts of protonscisortranshave significant contributions from both effects. The reaction field effects can also account for the methyl shifts in acetone.

ISSN:0008-4042    

DOI:10.1139/v67-182

出版商:NRC Research Press    

年代:1967

数据来源: NRC