scholarly journals Prediction of Standard Heat Capacity and Entropy of Inorganic XY3, XY4 and XY5 Gases at 25 degrees C Based on Correlation with the Normal Boiling Point.

1989 ◽  
Vol 43 ◽  
pp. 758-762 ◽  
Author(s):  
Reidar Stølevik ◽  
I. G. Krogh Andersen ◽  
G. Ploug-Sørensen ◽  
Ewa Huskowska ◽  
Mauri Lounasmaa ◽  
...  
Keyword(s):  
Heat Capacity ◽  
Boiling Point ◽  
Normal Boiling Point ◽  
Standard Heat ◽  
Standard Heat Capacity

A study of the electrolytic solution process using the scaled particle theory. 5. Heat capacity of aqueous ions at elevated temperatures

1991 ◽  
Vol 69 (3) ◽  
pp. 440-450
Author(s):  
Utpal Sen
Keyword(s):  
Heat Capacity ◽  
Elevated Temperatures ◽  
Solution Process ◽  
Scaled Particle Theory ◽  
Thermodynamic Quantities ◽  
Particle Theory ◽  
Standard Heat ◽  
Born Model ◽  
Standard Heat Capacity ◽  
Aqueous Ions

A theory composite of the scaled particle theory and the Born model of solvent continuum has been used to theoretically calculate the standard heat capacity of hydration as well as the partial molal heat capacity of aqueous ions and electrolytes at elevated temperatures. The uncertainties in the second temperature derivatives of solvent dielectric constant at various temperatures present a barrier to an accurate heat capacity prediction by the theory. Nevertheless, the agreement between the predicted standard heat capacity of electrolytes in solution and the corresponding experimental data, particularly at higher temperatures, is encouraging. Moreover, the composite theory seems to provide the most accurate thermodynamic predictions to date for aqueous electrolytes at higher temperatures without involving any arbitrary adjustable parameter. We therefore use this theory to find the proper ionic scale of the partial molal heat capacities at elevated temperatures. Key words: scaled particle theory, solvent continuum model of Born, standard heat capacity of aqueous ions, absolute scale for hydration thermodynamic quantities.

scholarly journals Evaluation of material property estimating methods for n-alkanes, 1-alcohols, and methyl esters for droplet evaporation calculations

2021 ◽  
Author(s):  
Dávid Csemány ◽  
István Gujás ◽  
Cheng Tung Chong ◽  
Viktor Józsa
Keyword(s):  
Heat Capacity ◽  
Liquid Phase ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Vapor Phase ◽  
Material Properties ◽  
Boiling Point ◽  
Methyl Esters ◽  
Normal Boiling Point ◽  
Proper Estimation

AbstractModeling of heat and mass transfer in liquid fuel combustion requires several material properties in a wide temperature and pressure range. The unavailable data are commonly patched with various estimation methods. In this paper, group contribution methods (GCM) and law of corresponding states (LCS) were analyzed for estimating material properties of n-alkanes (up to C10H22 and C12H26), 1-alcohols (up to C10H22O), and methyl esters (up to C19H38O2 and C19H36O2). These were compared to reference data to evaluate their applicability. LCS suggested by Poling et al. provides proper estimation for the acentric factor. GCM of Joback accurately estimates normal boiling point, critical properties, and specific heat capacity of the vapor-phase, the latter was corrected for methanol, however, GCM of Constantinou is more accurate for critical pressure of methyl esters. GCM of Ruzicka is suitable for estimating liquid-phase specific heat capacity. This method was updated for methanol. GCM of Elbro gives a proper estimation for liquid-phase density, while LCS of Lucas estimates vapor-phase viscosity properly. LCS of Chung and the modified Eucken method for vapor-phase and GCM of Sastri for liquid-phase thermal conductivity are appropriate. Considering the gas-phase mutual diffusion coefficient, the method of Fuller provides the best estimation, while LCS methods of Riedel and Chen are suitable for the enthalpy of vaporization at the normal boiling point.

scholarly journals Calorimetric Research into the Heat Capacity of Novel Nano-Sized Cobalt(Nickelite)-Cuprate-Manganites of LaBaMeIICuMnO6 (MeII = Co, Ni) and their Thermodynamic Properties

2020 ◽  
Vol 22 (1) ◽  
pp. 27
Author(s):  
B.K. Kassenov ◽  
Sh.B. Kassenova ◽  
Zh.I. Sagintaeva ◽  
E.E. Kuanyshbekov ◽  
M.O. Turtubaeva
Keyword(s):  
Experimental Data ◽  
Heat Capacity ◽  
Calculated Data ◽  
Heat Capacities ◽  
Fundamental Constants ◽  
Debye Theory ◽  
Standard Heat ◽  
Standard Heat Capacity ◽  
Dynamic Calorimetry ◽  
Temperature Dependences

The isobaric heat capacities of novel nano-sized cobalt-cuprate-manganite of lanthanum and barium LaBaCoCuMnO6 and nickel-cuprate-manganite of lanthanum and barium LaBaNiCuMnO6 were investigated by dynamic calorimetry over the temperature range of 298.15‒673 K. It is found that a λ-shaped effect is observed on the curve of the heat capacity dependence on temperature of LaBaCoCuMnO6 at 523 K, while LaBaNiCuMnO6 also has a similar effect at 473 K. Equations for the temperature dependence of the heat capacity of cobalt(nickelite)-cuprate-manganite of lanthanum and barium are derived with allowance for the temperatures of phase transitions. Based on the experimental data, the fundamental constants ‒ the standard heat capacities of the compounds under study were found. Irrespective of the experimental data, we also calculated the standard heat capacities of the mentioned compounds using the Debye theory using the characteristic temperatures of the elements, their melting points, the Koref and Nernst-Lindemann equations. The obtained calculated data on C0p (298.15) of the compounds were in satisfactory agreement with the experimental data on the standard heat capacity. The standard entropies of LaBaCoCuMnO6 and LaBaNiCuMnO6 were calculated by the ion increment method. We calculated the temperature dependences of the enthalpy Ho(T)- Ho(298.15), entropy ΔSo(T), and the reduced thermodynamic potential ΔФ**(Т).

The Realization of the Normal Boiling Point of Neon

Metrologia ◽  
1978 ◽  
Vol 14 (1) ◽  
pp. 9-13 ◽  
Author(s):  
R C Kemp ◽  
W R G Kemp
Keyword(s):  
Boiling Point ◽  
Normal Boiling Point

Exciplex-Based Vapor/Liquid Visualization Systems Appropriate for Automotive Gasolines

1993 ◽  
Vol 47 (6) ◽  
pp. 782-786 ◽  
Author(s):  
Lynn A. Melton
Keyword(s):  
Cross Talk ◽  
Spectral Region ◽  
Boiling Point ◽  
Automotive Gasoline ◽  
Normal Boiling Point ◽  
Tertiary Amines ◽  
Temperature Range ◽  
Exciplex Emission ◽  
Visualization Systems ◽  
Vapor Liquid

This paper reports the development of exciplex-based vapor/liquid visualization systems based on exciplexes formed from tertiary amines and fluorine-substituted benzene and/or toluene. These systems are expected to be virtually coevaporative with solvents (fuels) boiling in the temperature range 70 to 110°C and thus are expected to track the vaporization of automotive gasoline effectively. A system consisting of 10% triethylamine/0.5% fluorobenzene/89.5% hexane should be coevaporative with a normal boiling point of 69°C. A system consisting of 10% n-propyldiethylamine/0.5% 4-fluorotoluene/89.5% isooctane should be coevaporative with a normal boiling point of approximately 100°C. Although the coevaporation of these systems is excellent, the exciplexes revert to varying extents to excited monomer at temperatures near 100°C. Thus there is considerable cross talk from the liquid into the vapor spectral region. The tertiary amines generally require excitation at wavelengths below 250 nm; the fluorobenzene or 4-fluorotoluene can be excited at 266 nm. Monomer emission peaks at 290 nm; exciplex emission peaks at 350 nm.

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