Journal Articles (before-1995)
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Item Excess Enthalpies of some Binary Mixtures of 1,2-Dichloroethane and Hydrocarbons(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (1), 1977) Mahl, B. S.; Khurma, J. R.The excess enthalpies of mixtures of 1,2-dichloroethane with cyclohexane, benzene, toluene, o-, in- and p-xylenes have been measured at 298.15 K. 7/E values for the first two systems are found to be positive over the entire composition range whereas //E changes sign with composition in the rest of the systems. Examination of the results shows that there appears to be some kind of specific interaction between aromatic hydrocarbons and 1,2-dichloroethane.Item Hydrogenolysis of some Saturated Hydrocarbons over a Platinum Black Catalyst(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (11), 1974) Guczi, L.; Sarkany, A.; Tetenyi, P.Deuterium exchange reactions of methane, ethane, propane and neopentane, and the hydrogenolysis and isomerization of ethane, propane, n-butane and isobutane on platinum black have been studied in the temperature range 363–743 K. There is a gap of 150 K between the temperature of deuterium exchange and that of hydrogenolysis and isomerization. Only at high hydrogen pressure (about 50 kN m–2) and at low catalytic activity is the hydrogenolysis characterized by selective loss of a terminal methyl group, except for n-butane in which there is an equal chance of any of the C—C bond rupturing. The selectivity for isomerization has a maximum at high hydrogen pressure. These values together with kinetic data suggest that the ability of platinum in an exchange reaction to convert weakly bonded intermediates into strongly bonded ones is much less than that of nickel. The phenomenon of π-olefin and π-allyl bond conversion is applied in part to explain the results obtained. Brief comparison is given between the catalytic properties of platinum and those of nickel for the reactions investigated.Item Reactions of Energetic Hydrogen Atoms with Simple Hydrocarbons Part 1.—The Effect of Moderators(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (5), 1973) Terry, R.; Baker, K.The reactions of recoil tritium atoms with ethane have been studied in the presence of N2 and CF^ moderators. The results suggest that collisional dissociation of excited HT, initially produced by direct reaction, may be more important in determining the ratio of final products than the commonly described effect of energy shadowing. It is suggested that hydrocarbons behave essentially as carbon atoms as far as their ability to collisionally dissociate HT is concerned, and that moderators which consist of groups which are similar in mass to carbon atoms, exert very little effect on observed product ratios.Item Thermal Conductivities of Gaseous Mixtures Containing Hydrocarbons: Part 2.—Cyclopropane, Propene, But-l-ene and trans-But-2-ene, and Their Binary Mixtures with Argon(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (6), 1972) Parkinson, C.; Mukhopadhyay, P.; Gray, P.Thermal conductivities of the four pure gases cyclopropane, propene, but-l-ene and trans-but-2- ene and their binary mixtures with argon have been measured at both 50 and 100°C. The thermal conductivities of the pure polyatomic gases lie close together and strong similarities exist in the conductivity versus composition curves for each binary mixture. At 50°C thermal conductivities of the mixtures arc less than the molar average values and a broad minimum results in each case. At 100°C negative deviations are much reduced and only the trans- but-2-cne with argon system displays a minimum. Points of inflexion develop for the cyclopropane, propene and but-l-enc mixtures at this temperature and thermal conductivities slightly above molar average values arc seen in regions of high hydrocarbon concentration. Thermal conductivities of the binary mixtures calculated on the basis of an empirical equation and from approximations to rigorous kinetic theory (Hirschfelder-Euckcn and Monchick, Pereira and Mason) arc compared with the experimental results. All three methods of calculation are found to give reasonably good agreement with experiment, but the Hirschfcldcr-Eucken approximation is the most satisfactory (mean deviation 0.89 % from 72 compositions) for these mixtures.Item Thermal Conductivities of Gaseous Mixtures Containing Hydrocarbons: Part 1.—n-Butane, iso-Butane, iso-Pentane and neo-Pentane, and Their Binary Mixtures With Argon(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (6), 1972) Parkinson, C.; Gray, P.Thermal conductivities of the four pure gases n-butane, iso-butane, iso-pentanc and nco-pentane and of their binary mixtures with argon have been measured at 50 and 100°C. The thermal conductivities of all four polyatomic gases lie close together and there arc marked similarities in the conductivity against composition curves for their binary mixtures with argon. Thermal conductivities less than molar average values are found at both 50 and 100 C for each mixture. These “ negative deviations ” arc greatest at 50nC and result in broad minima in each case. At 100 C minima arc less pronounced and arc confined to the n-butane, iso-pentane and neo-pcntanc mixtures. Points of inflexion develop in all the conductivity against composition curves at this temperature. We believe that negative deviations are generally to be associated with binary mixtures of a monatomic with a non-polar polyatomic gas, and minima can be manifested when the ratio of thermal conductivities for the pure components (Xj/X/) is not far from unity. The formal condition is AjjAji > where Ay and Aji arc coefficients of the Suthcrland-Wassiljcwa equation and subscript i denotes the component with the lower thermal conductivity. The data arc used to test predictions of thermal conductivities of gas mixtures both by approximations to rigorous kinetic theory (Hirschfelder-Eucken, and Monchick, Pereira and Mason) and by the empirical relationship of Lindsay and Bromley. All three methods predict thermal conductivities which arc in reasonable agreement with experimental measurements, but the Hirschfelder-Eucken approximation is found to be most satisfactory (mean deviation 1.27 % from 74 compositions) for these mixtures.