High Temperature Aqueous Electrolyte Concentration Cells and the Ionization of Liquid Water to 200 °C

1973 ◽  
Vol 51 (15) ◽  
pp. 2590-2595 ◽  
Author(s):  
Digby D. MacDonald ◽  
P. Butler ◽  
D. Owen
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Thermodynamic Parameters ◽  
Liquid Water ◽  
Infinite Dilution ◽  
Electrolyte Concentration ◽  
Aqueous Electrolyte ◽  
Ionization Constant ◽  
Liquid Junction ◽  
Concentration Cells

High temperature aqueous electrolyte concentration cells with and without liquid junction are described. These cells were used to measure the ionization constant of water in 0.1, 0.25,0.5, and]1.0 mol/kg KCl solutions at temperatures to 200 °C. Extrapolation to infinite dilution yielded the following functions for the temperature dependence of log Kw0 and the thermodynamic parameters for ionization: log Kw0 = −4046.16/T + 3.537 − 0.01323T; ΔG0 = 77458.0 − 67.71T + 0.253187T2 J/mol; ΔH0 = 77458.0 − 0.253187T2 J/mol; ΔS0 = 67.71 − 0.5063T J/K mol; ΔCp0 = −0.5063T J/K mol.

The ionization constant of heavy water (D2O) in the temperature range 298 to 523 K

1976 ◽  
Vol 54 (22) ◽  
pp. 3553-3558 ◽  
Author(s):  
David William Shoesmith ◽  
Woon Lee
Keyword(s):  
Heat Capacity ◽  
Free Energy ◽  
Heavy Water ◽  
Electrolyte Concentration ◽  
Aqueous Electrolyte ◽  
Ionization Constant ◽  
Standard Free Energy ◽  
Concentration Cell ◽  
Temperature Range

The ionization constant of liquid D2O has been measured over the temperature range 298 to 523 K using an aqueous electrolyte concentration cell. Values for the standard free energy, enthalpy, entropy, and heat capacity of ionization have been calculated. The results are compared to similar results for liquid H2O

Transport Numbers for Hydrochloric Acid at Elevated Temperatures

1973 ◽  
Vol 51 (16) ◽  
pp. 2747-2749 ◽  
Author(s):  
DiGBY D. Macdonald ◽  
D. Owen
Keyword(s):  
Hydrochloric Acid ◽  
Temperature Dependence ◽  
Liquid Water ◽  
Infinite Dilution ◽  
Thermal Destruction ◽  
Elevated Temperatures ◽  
Transport Number ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Transport Numbers

Transport numbers for H+ and Cl− have been measured as a function of concentration and temperature to 200 °C using electrolyte concentratio cells. The infinite dilution transport number for H+ decreases with temperature while that for Cl− increases. This temperature dependence is discussed in terms of thermal destruction of the three dimensional structure of liquid water.

ABOUT HEAT CAPACITY OF TITANIUM CARBIDE TiCx

2019 ◽  
pp. 56-66
Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov
Keyword(s):  
Heat Capacity ◽  
High Temperature ◽  
Titanium Carbide ◽  
Temperature Dependence ◽  
Carbon Concentration ◽  
Room Temperature ◽  
Thermodynamic Characteristics ◽  
Liquid Nitrogen Temperature ◽  
Analysis Data ◽  
Thermal Excitation

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

The Microscopic Structure Of Shallow Donors In Silicon Carbide

1996 ◽  
Vol 442 ◽  
Author(s):  
J.-M. Spaeth ◽  
S. Greulich-Weber ◽  
M. März ◽  
E. N. Kalabukhova ◽  
S. N. Lukin
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Temperature Dependence ◽  
Double Resonance ◽  
Epr Spectra ◽  
Electron Nuclear Double Resonance ◽  
Paramagnetic Resonance ◽  
Vacancy Pair ◽  
Temperature Spectra ◽  
Electron Paramagnetic

AbstractThe electronic structure of nitrogen donors in 6H-, 4H- and 3C-SiC is investigated by measuring the nitrogen hyperfine (hf) interactions with electron nuclear double resonance (ENDOR) and the temperature dependence of the hf split electron paramagnetic resonance (EPR) spectra. Superhyperfine (shf) interactions with many shells of 13C and 29Si were measured in 6H-SiC. The hf and shf interactions are discussed in the framework of effective mass theory. The temperature dependence is explained with the thermal occupation of the lowest valley-orbit split A1 and E states. It is proposed that the EPR spectra of P donors observed previously in neutron transmuted 6H-SiC at low temperature (<10K) and high temperature (>60K) are all due to substitutional P donors on the two quasi-cubic and hexagonal Si sites, whereby at low temperature the E state is occupied and at high temperature the A1 state. The low temperature spectra are thus thought not to be due to P-vacancy pair defects as proposed previously.

Temperature Dependence of Positron Annihilation Parameters in High Temperature Superconductors

1992 ◽  
Vol 105-110 ◽  
pp. 477-484 ◽  
Author(s):  
C.S. Sundar ◽  
A. Bharathi ◽  
Yan Ching Jean ◽  
W.Y. Ching ◽  
X. Lu ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Dependence ◽  
Positron Annihilation ◽  
High Temperature Superconductors

Sorbitol dehydration in high temperature liquid water

2011 ◽  
Vol 13 (4) ◽  
pp. 873 ◽  
Author(s):  
Aritomo Yamaguchi ◽  
Norihito Hiyoshi ◽  
Osamu Sato ◽  
Masayuki Shirai
Keyword(s):  
High Temperature ◽  
Liquid Water ◽  
Temperature Liquid

Temperature dependence of intramolecular disorder in the high-temperature phase of poly(tetrafluoroethylene) (phase I)

1988 ◽  
Vol 21 (4) ◽  
pp. 1174-1176 ◽  
Author(s):  
C. De Rosa ◽  
G. Guerra ◽  
V. Petraccone ◽  
R. Centore ◽  
P. Corradini
Keyword(s):  
High Temperature ◽  
Phase I ◽  
Temperature Dependence ◽  
High Temperature Phase ◽  
Temperature Phase
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