scholarly journals Thermodynamic study of a synthetic analog of the famatinite mineral - Cu3SbS4

2021 ◽  
Vol 22 (1) ◽  
pp. 53-58
Author(s):  
P.R. Mammadli ◽  
L.F. Mashadiyeva ◽  
Z.T. Hasanova ◽  
D.M. Babanly

Fundamental thermodynamic properties of the synthetic analog of the famatinite mineral - Cu3SbS4 were studied on the basis of electromotive force (EMF) measurements. The EMF of the concentration chains relative to the Cu electrode with a solid electrolyte was measured for the alloys from the Cu3SbS4 + Sb2S3 + S phase region at 300-380K temperature interval. Based on measurement data, the relative partial thermodynamic functions of copper in alloys, the standard thermodynamic functions of formation, as well as, the standard entropy of the Cu3SbS4 ternary compound were calculated for the first time.

2021 ◽  
Vol 22 (3) ◽  
pp. 420-425
Author(s):  
Samira Imamaliyeva

The alloys of the Gd-Te system in the range of compositions > 75 at% Te were studied by the methods of X-ray diffraction (XRD) and electromotive forces (EMF). From the EMF measurements of the concentration cells relative to the GdTe electrode in the 300-450 K temperature range, the partial thermodynamic functions of GdTe in alloys were determined. By combining these data with the corresponding functions of Gd in GdTe, the partial molar functions of gadolinium in GdTe3+Te alloys, and standard thermodynamic functions of formation and standard entropy of the GdTe3 compound were calculated. The obtained results were compared with the literature data.


2021 ◽  
Vol 102 (2) ◽  
pp. 43-52
Author(s):  
S.Z. Imamaliyeva ◽  
◽  
I.F. Mekhdiyeva ◽  
Y.I. Jafarov ◽  
M.B. Babanly ◽  
...  

In this study the phase equilibria in the Tl2Te–Tl2Te3–TlTmTe2compositions area of the Tl–Tm–Te ternary system were studied by powder X-ray diffraction (PXRD) analysis. Based on PXRD data, the solid-phase equi-libria diagram was plotted. The thermodynamic functions of the Tl9TmTe6and TlTmTe2ternary compounds were calculated by the electromotive forces method. The electrochemical cells of the following type (−) TmТе (s.) | glycerol + KCl + TmCl3 | (Tm in alloys of Tl–Tm–Te system) (s.) (+) were assembled and their EMF were measured in the 300-450 Ktemperature range. Based on obtained EMF data for the Tl2Te3–TlTe–TlTmTe2and TlTe–TlTmTe2–Tl9TmTe6three-phase regions, the relative partial thermodynamic functions of TmTe in alloys were calculated. The combination of these functions with the partial molar functions of thulium in TmTe allowed calculating the corresponding partial functions of thulium in the above phase regions. The potential-forming reactions responsible for the indicated partial molar values were obtained based on con-structed solid-phase equilibria diagram. Using indicated potential-forming reactions, for the first time, the standard thermodynamic functions of formation and standard entropies of the Tl9TmTe6and TlTmTe2 compounds were calculated.


2020 ◽  
Vol 21 (4) ◽  
pp. 714-719
Author(s):  
G.S. Hasanova ◽  
A.I. Aghazade ◽  
Y.A. Yusibov ◽  
M.B. Babanly

Two-phase alloys Bi8Te9+Bi4Te5 and BiTe+Bi8Te9 were studied by the electromotive forces method (EMF) in the temperature range 300-450 K. From the EMF data, the relative partial molar functions of bismuth in the alloys were calculated. The potential-forming reactions responsible for these partial functions were compiled, the values of the standard thermodynamic functions of formation, and the standard entropies of Bi8Te9 and BiTe compounds were calculated. A comparative analysis of the data for BiTe with the literature data was carried out; for Bi8Te9, the thermodynamic functions were obtained for the first time.


2021 ◽  
Vol 0 (4) ◽  
pp. 60-66
Author(s):  
U.N. Sharifova ◽  

By the method of electromotive forces measuring concentration chains: Pt│Li2O│ ZrO2+10 wt% Y2O3, lithium glass. (Li2O)x(TiO2)1-x│Pt in the temperature range T=1000–1200K and concentrations 0.35÷0.95 mol fraction TiO2, the thermodynamic functions of the formation of the compounds Li4TiO4, Li2TiO3, Li4Ti5O12 and phases based on Li2TiO3:Li1.92Ti1.04O3.04, Li2.12Ti0.94O2.92 were determined. With the exception of the compound Li2TiO3, the thermodynamic functions of the formation of lithium titanates are deter¬mined for the first time. The thermodynamic functions of formation are calculated for the 1200 K and for the standard state at 298 K. The thermodynamic functions of the formation of lithium titanates are determined from simple substances and from binary compounds Li2O and TiO2. In particular, for the free energy, enthalpy of formation and standard entropy we obtained: ∆G_298^0(Li4TiO4)=–2149 kJ∙mol-1; ∆G_298^0(Li2TiO3)=–1565; ∆G_298^0(Li4Ti5O12)=–5923; ∆H_298^0(Li4TiO4)=–2286 kJ∙mol-1; ∆H_298^0(Li2TiO3)=–1662; ∆H_298^0(Li4Ti5O12)=–6287; S_298^0(Li4TiO4)=119.1 J∙mol-1∙K-1; S_298^0(Li2TiO3)=84; S_298^0(Li4Ti5O12)=315.7


1985 ◽  
Vol 63 (4) ◽  
pp. 789-792 ◽  
Author(s):  
Norman H. Sagert ◽  
Danny W. P. Lau

The distribution of four branched chain octanols, 3-ethyl-3-hexanol, 4-ethyl-3-hexanol, 2-ethyl-4-methylpentanol, and 4-octanol, has been measured between dodecane and water. Measurements were made at alcohol concentrations in the dodecane of less than 0.1 mol/dm3, and as a function of temperature from 10 °C to 35 °C. From these distribution data, standard thermodynamic functions for transfer were calculated. Standard Gibbs energies of transfer from water to dodecane at 25 °C were in the range −14.1 to −15.1 kJ/mol, whereas the standard enthalpies of transfer at 25 °C varied from 29 to 39 kJ/mol. Thus, the change in the standard enthalpy tends to inhibit transfer, but a large standard entropy of transfer results in dodecane being the favoured phase.


Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1557
Author(s):  
Semen S. Sologubov ◽  
Alexey V. Markin ◽  
Natalia N. Smirnova ◽  
Elena S. Chamkina ◽  
Irina Yu. Krasnova ◽  
...  

The molar heat capacity of the first-generation hybrid dendrimer with a “carbosilane core/phenylene shell” structure was measured for the first time in the temperature range T = 6–600 K using a precise adiabatic vacuum calorimeter and DSC. In the above temperature interval, the glass transition of the studied compound was observed, and its thermodynamic characteristics were determined. The standard thermodynamic functions (the enthalpy, the entropy, and the Gibbs energy) of the hybrid dendrimer were calculated over the range from T = 0 to 600 K using the experimentally determined heat capacity. The standard entropy of formation of the investigated dendrimer was evaluated at T = 298.15 K. The obtained thermodynamic properties of the studied hybrid dendrimer were compared and discussed with the literature data for some of the first-generation organosilicon and pyridylphenylene dendrimers.


2021 ◽  
Vol 0 (4) ◽  
pp. 53-59
Author(s):  
F.R. Aliyev ◽  
◽  
E.N. Orujlu ◽  
D.M. Babanly ◽  
◽  
...  

Thermodynamic properties of the Sb2Te3 compound were studied by measuring electromotive force (EMF) with a liquid electrolyte in the temperature range of 300-450 K. The partial molar functions of antimony in alloys and the corresponding standard integral thermodynamic functions of the Sb2Te3 compound were calculated for the first time based on the EMF measurements under standard conditions. Comparative analysis of obtained results with literature data was carried out


2019 ◽  
Vol 107 (2) ◽  
pp. 95-104
Author(s):  
Ru-Shan Lin ◽  
You-Qun Wang ◽  
Zhao-Kai Meng ◽  
Hui Chen ◽  
Yan-Hong Jia ◽  
...  

Abstract In this study, UCl4 was prepared by the reaction of HCl gas with UO2 in the LiCl-KCl eutectic. Then, the electrochemical behavior of U4+ and U3+ on a Mo cathode was investigated by various electrochemical techniques. The reduction process of U4+ was regarded as two steps: U4++e=U3+; U3++3e=U. Diffusion coefficients of U4+ and U3+, the apparent standard potential of U4+/U3+, U3+/U as well as U4+/U in the LiCl-KCl molten salt on the Mo electrode was determined by numerous electrochemical methods. The thermodynamic functions of formation of Gibbs free energy of UCl4 and UCl3 are calculated as well.


2021 ◽  
Vol 27 (1) ◽  
pp. 78-84
Author(s):  
D.I. Vlasov ◽  
◽  
A.S. Parnowski ◽  

For the first time in world practice, predictive models were constructed for X, Y, Z geomagnetic elements. Based on these models, the prediction was made with 3 hours lead time using data of the “Lviv” magnetic observatory. The properties of models are as follows: observatory — LVV, рredicted values — XYZ; lead time — 3 hours; correlation coefficients’ averaged measurement data — 0.824 (X), 0.811 (Y), 0.804 (Z); prediction efficiency — 0.816 (X), 0.803 (Y), 0.801 (Z); skill score — 0.115 (X), 0.095 (Y), 0.099 (Z). The developed models were tested in the Main Center of Special Monitoring, and they were found to meet the Basic Requirements for operational predictive models.


Sign in / Sign up

Export Citation Format

Share Document