Temperature dependence of heats of vaporization, saturated vapour pressures and cohesive energies of secondary amines

1979 ◽  
Vol 44 (12) ◽  
pp. 3533-3540 ◽  
Author(s):  
Libor Pětroš ◽  
Vladimír Majer ◽  
Josef Koubek ◽  
Václav Svoboda ◽  
Jiří Pick

The temperature dependence of heats of vaporization of methylisopropylamine, ethylisopropylamine, propylisopropylamine, diisopropylamine, butylisopropylamine, ethylbutylamine and dibutylamine has been measured. Further, the dependence of saturated vapour pressures on temperature has been measured for methylisopropylamine, ethylisopropylamine, propylisopropylamine, butylisopropylamine, diisopropylamine and ethylbutylamine. The densities of the liquid phase at 25°C have been determined for methylisopropylamine, ethylisopropylamine, propylisopropylamine, butylisopropylamine and ethylbutylamine. The cohesive energies at several temperatures have been computed from the experimental data for all the substances of the set.

1979 ◽  
Vol 44 (12) ◽  
pp. 3521-3528 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Josef Koubek ◽  
Jiří Pick

The temperature dependences of heats of vaporization of propylamine, isopropylamine, butylamine, isobutylamine, sec-butylamine, cyclohexylamine, diethylamine and triethylamine and saturated vapour pressures of butylamine, isobutylamine, sec-butylamine and triethylamine were measured. The cohesive energies of amines studied in dependence on temperature were calculated from the experimental values.


1979 ◽  
Vol 44 (3) ◽  
pp. 637-651 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Slavoj Hála ◽  
Jiří Pick

Heats of vaporization of a group of 10 alkanes C6-C8 and 2 cycloalkanes were measured in a temperature range of 25-80 °C. By combining the obtained results with selected literature data, a set of very accurate values of heats of vaporization as functions of temperature was made up for 22 saturated C5-C8 hydrocarbons. This set was employed for the verification of the proposed estimation method for the determination of heat of vaporization which is based on the principle of combination of a contribution method with constant entropy-of-vaporization rules. In this way it is then possible to estimate heats of vaporization of C4-C9 alkanes with an error lower than 0.5%.


1999 ◽  
Vol 54 (3-4) ◽  
pp. 229-235 ◽  
Author(s):  
M. Gaune-Escard ◽  
L. Rycerz

The heat capacities of the solid and liquid K3LnCl6 compounds (Ln = La, Ce, Pr, Nd) have been determined by differential scanning calorimetry (DSC) in the temperature range 300 -1100 K. Their temperature dependence is discussed in terms of the phase transitions of these compounds as reported in literature. The heat capacity increases and decreases strongly in the vicinity of a phase transition but else varies smoothly. The Cp data were fitted by an equation which provides a satisfactory representation up to the temperatures of Cp discontinuity. The measured heat capacities were checked for consistency by calculating the enthalpy of formation of the liquid phase, which had been previously measured. The results obtained compare satisfactorily with these experimental data.


1980 ◽  
Vol 45 (11) ◽  
pp. 3063-3068 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Antonín Pošta ◽  
Jiří Pick

Some physico-chemical properties were determined for 1,1,1-trichlorotrifluoroethane, 1,1,2-trichlorotrifluoroethane, 1-bromo-1-chloro-2,2,2-trifluoroethane and 1,2-dichlorohexafluoropropane. For all the substances, their heats of vaporization in dependence on temperature were measured and their densities and refractive indices at two temperatures were determined. For 1,1,1-trichlorotrifluoroethane and 1,2-dichlorohexafluoropropane the saturated vapour pressures were measured, too. The temperature dependences of standard heats of vaporization, vaporization internal energies and cohesive energies were determined on the basis of the experimental data.


1981 ◽  
Vol 46 (4) ◽  
pp. 817-822 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Antonín Pošta ◽  
Jiří Pick

Some thermodynamic properties were investigated for three fluorinated halogen ethanes: 1-bromo-2-chloro-1,1,2-trifluoroethane, 1,2-dibromotetrafluroethane and 1,2-dibromo-1-chlorotrifluoroethane. The temperature dependence of heats of vaporization, saturated vapour pressures, densities and refractive indices was measured at two temperatures. On the basis of the experimental quantities obtained, the standard heats of vaporization and the cohesive and internal energies of vaporization in their dependence on temperature were determined.


1982 ◽  
Vol 47 (2) ◽  
pp. 543-549 ◽  
Author(s):  
Václav Svoboda ◽  
Vladimíra Charvátová ◽  
Vladimír Majer ◽  
Vladimír Hynek

The temperature dependence of heats of vaporization and some other derived thermodynamic properties were determined for four substituted hydrocarbons, viz. 2,2,4-trimethylpentane,1-octene, ethylbenzene and n-butylbenzene. The temperature dependence of heats of vaporization was measured and, on the basis of these data, the values of standard heats of vaporization, internal and cohesive energies, entropies of vaporization and the difference of heat capacities of liquid and vapour at constant pressure and along the saturated vapour pressure curve were computed.


1981 ◽  
Vol 46 (12) ◽  
pp. 2983-2988 ◽  
Author(s):  
Václav Svoboda ◽  
Vladimíra Charvátová ◽  
Vladimír Majer ◽  
Jiří Pick

Heats of vaporization and some other related thermodynamic quantities were determined for the four alkylcycloparaffins: ethylcyclopentane, n-butylcyclopentane, ethylcyclohexane and tert-butylcyclohexane. The temperature dependence of heats of vaporization was measured and employed for calculating standard heats of vaporization, internal and cohesive energies of vaporization, entropies of vaporization, and differences between heat capacities of liquids and vapours at constant pressure and along the saturation line of vapours.


2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.


1986 ◽  
Vol 51 (6) ◽  
pp. 1222-1239 ◽  
Author(s):  
Pavel Moravec ◽  
Vladimír Staněk

Expression have been derived in the paper for all four possible transfer functions between the inlet and the outlet gas and liquid steams under the counter-current absorption of a poorly soluble gas in a packed bed column. The transfer functions have been derived for the axially dispersed model with stagnant zone in the liquid phase and the axially dispersed model for the gas phase with interfacial transport of a gaseous component (PDE - AD). calculations with practical values of parameters suggest that only two of these transfer functions are applicable for experimental data evaluation.


1982 ◽  
Vol 47 (7) ◽  
pp. 1780-1786 ◽  
Author(s):  
Rostislav Kudláček ◽  
Jan Lokoč

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.


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