Temperature dependence of heats of vaporization of saturated hydrocarbons C5-C8; Experimental data and an estimation method

1979 ◽  
Vol 44 (3) ◽  
pp. 637-651 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Slavoj Hála ◽  
Jiří Pick
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Estimation Method ◽  
Saturated Hydrocarbons ◽  
Heat Of Vaporization ◽  
Temperature Range ◽  
Entropy Of Vaporization ◽  
Heats Of Vaporization

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%.

scholarly journals Температурная зависимость ширины запрещенной зоны монокристаллов MnAgIn-=SUB=-7-=/SUB=-S-=SUB=-12-=/SUB=-

2019 ◽  
Vol 53 (12) ◽  
pp. 1621
Author(s):  
И.В. Боднарь ◽  
Б.Т. Чан ◽  
В.Н. Павловский ◽  
И.Е. Свитенков ◽  
Г.П. Яблонский
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Band Gap ◽  
Single Crystals ◽  
Spinel Structure ◽  
Semiconductor Materials ◽  
Transmittance Spectra ◽  
Temperature Range

AbstractMnAgIn_7S_12 single crystals 16 mm in diameter and ~40 mm in length are grown by planar crystallization of the melt. It is shown that the material grown crystallizes with the formation of the cubic spinel structure. From the transmittance spectra recorded in the region of fundamental absorption in the temperature range 10–320 K, the band gap E _ g of the single crystals and its temperature dependence are determined. The dependence has a shape typical of most semiconductor materials: as the temperature is lowered, the band gap E _ g increases. A calculation is carried out, and it is shown that the calculated values are in agreement with the experimental data.

Verification of the calculation of the constant-volume heat capacity difference of substances in the liquid and gas phases from the temperature dependence of heat of vaporization

1983 ◽  
Vol 48 (8) ◽  
pp. 2141-2146
Author(s):  
Věra Uchytilová ◽  
Václav Svoboda
Keyword(s):  
Heat Capacity ◽  
Temperature Dependence ◽  
Constant Volume ◽  
Heat Of Vaporization ◽  
Gas Phases ◽  
Volume Heat ◽  
Pure Substances ◽  
The Difference ◽  
Heats Of Vaporization ◽  
The Ideal

The possibilities were verified of the proposed method for calculating the difference between constant-volume heat capacities of liquids and gases in the ideal state from known data on the volumetric behaviour and temperature dependence of heats of vaporization of pure substances.

g-Values for γ-irradiated water as a function of temperature

1990 ◽  
Vol 68 (5) ◽  
pp. 712-719 ◽  
Author(s):  
A. John Elliot ◽  
Monique P. Chenier ◽  
Denis C. Ouellette
Keyword(s):  
Experimental Data ◽  
Hydrogen Peroxide ◽  
Hydroxyl Radical ◽  
Temperature Dependence ◽  
Atomic Hydrogen ◽  
Molecular Hydrogen ◽  
Hydrated Electron ◽  
Temperature Range ◽  
Increasing Temperature

The g-values of primary species formed in the γ-radiolysis of water have been estimated for the temperature range 25–300 °C. The g-values for the hydrated electron, the hydroxyl radical, and molecular hydrogen all increase approximately 50% over this temperature range. The g-values for the minor products, hydrogen peroxide and atomic hydrogen, probably also increase with temperature; however, there is evidence from some of the experimental data which suggests that these g-values may slightly decrease with increasing temperature. Keywords: radiolysis, g-values, temperature dependence.

Determination of Natural Loss of Gasoline and Diesel Fuel during the Tank Storage

2021 ◽  
Vol 627 (5) ◽  
pp. 28-31
Author(s):  
D .S. Kopitsyn ◽  
◽  
P. A. Gushchin ◽  
A. A. Panchenko ◽  
F. V. Timofeev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Temperature Dependence ◽  
Gas Phase ◽  
Diesel Fuel ◽  
Empirical Equation ◽  
Petroleum Products ◽  
Antoine Equation ◽  
Tank Storage

In this work, we studied the processes of evaporation of gasoline and diesel fuel during their storage. We assessed of the temperature dependence of the content of hydrocarbon vapors in the gas phase over petroleum products. It was found that the experimental data are best described by the empirical equation based on the Antoine equation. An algorithm is proposed for calculating the natural loss of gasoline and diesel fuel, as well as approaches to its reduction.

Calculation of the difference between molar heat capacity of liquid and ideal gas from the temperature dependence of heat of vaporization

1979 ◽  
Vol 44 (6) ◽  
pp. 1687-1697 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Jiří Pick
Keyword(s):  
Heat Capacity ◽  
Temperature Dependence ◽  
Molar Heat Capacity ◽  
A Priori ◽  
Maximum Error ◽  
Ideal Gas ◽  
Saturated Hydrocarbons ◽  
Heat Of Vaporization ◽  
The Difference ◽  
Experimental Values

A method was developed for calculating the difference ΔcP between molar heat capacity of liquid cP1 and of ideal gas cPgo from the temperature dependence of heat of vaporization. By an a priori analysis the maximum error of the calculation procedure was determined. The exploitation of the method was demonstrated on a group of 20 saturated hydrocarbons. Besides these ΔcP values, the data on cP1 and cPgo were calculated in the regions where no experimental data are available, by combining ΔcP with the experimental values of molar heat capacities.

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
Keyword(s):  
Experimental Data ◽  
Liquid Phase ◽  
Temperature Dependence ◽  
Secondary Amines ◽  
Saturated Vapour ◽  
Cohesive Energies ◽  
Heats Of Vaporization

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.

Optical Determination of Thermal Conductivity with a Plane Source Technique

1968 ◽  
Vol 23 (5) ◽  
pp. 682-686 ◽  
Author(s):  
Silas E. Gustafsson ◽  
Nils-Olov Halling ◽  
Rolf A. E. Kjellander
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Temperature Dependence ◽  
Theoretical Approach ◽  
Experimental Results ◽  
Plane Source ◽  
Melting Points ◽  
Temperature Range ◽  
Optical Determination

The thermal conductivity and the thermal diffusivity of the three alkali nitrates LiNO3 , RbNO3 and CsNO3 have been measured over a temperature range between 50° and 100 °C above their melting points. Any temperature dependence of the thermal conductivity cannot be established for any of the investigated liquids but the results indicate that it must be less than 10-3 °C-1. The experimental results are compared with the conductivities which can be calculated with already excisting theories. A somewhat modified theoretical approach is suggested for estimating the thermal conductivity, where no adjustable parameters are being used. The experimental and theoretical values at the melting points agree within about 10 percent.

A new calorimeter for determination of the temperature dependence of heat of vaporization

1978 ◽  
Vol 43 (5) ◽  
pp. 1313-1324 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Vladimír Hynek ◽  
Jiří Pick
Keyword(s):  
Temperature Dependence ◽  
Heat Of Vaporization

Determination of heats of vaporization and some other thermodynamic quantities for three fluorinated halogen ethanes

1981 ◽  
Vol 46 (4) ◽  
pp. 817-822 ◽  
Author(s):  
Vladimír Majer ◽  
Václav Svoboda ◽  
Antonín Pošta ◽  
Jiří Pick
Keyword(s):  
Thermodynamic Properties ◽  
Temperature Dependence ◽  
Refractive Indices ◽  
Thermodynamic Quantities ◽  
Saturated Vapour ◽  
Two Temperatures ◽  
Heats Of Vaporization

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.

Sign in / Sign up

Export Citation Format

Share Document