Determination of standard molar enthalpies of formation of Bi2Mo3O12 (s), Bi2MoO6 (s), Bi6Mo2O15 (s) and Bi6MoO12 (s) by solution calorimetry

2019 ◽  
Vol 682 ◽  
pp. 178401 ◽  
Author(s):  
P.M. Aiswarya ◽  
S. Shyam Kumar ◽  
Rajesh Ganesan ◽  
T. Gnanasekaran
Keyword(s):  
Solution Calorimetry ◽  
Enthalpies Of Formation

Thermochemisches und kalorisches Verhalten von NdAl3Cl12 / Thermochemical and Calorical Behaviour of NdAl3Cl12

1998 ◽  
Vol 53 (11) ◽  
pp. 1343-1351 ◽  
Author(s):  
H. Oppermann ◽  
M. Zhang ◽  
C. Hennig
Keyword(s):  
Total Pressure ◽  
Solid Phase ◽  
Chemical Transport ◽  
Solution Calorimetry ◽  
Enthalpies Of Formation ◽  
Melting Diagram ◽  
Heats Of Solution ◽  
Neodymium Chloride ◽  
The Enthalpy Of Formation

The thermodynamical data of solid and gaseous aluminium neodymium chloride have been obtained by determination of the decomposition equilibria (of solid) from total pressure measurements and chemical transport reactions (gaseous). The melting diagram was determined by DTA. The enthalpy of formation of the solid phase was calculated from their heats of solution and from the enthalpies of formation and the heats of solution of NdCl3 and AlCl3. Data by total pressure measurement: ΔH°B |(NdAl3Cl12,f,298) = -749,6 ± 2,5 kcal/mol; S°(NdAl3Cl12,f,298) = 118,2 ± 3,0 cal/K·mol. Data by solution calorimetry: ΔH°B(NdAl3Cl12,f,298) = -748,6 ± 1,3 kcal/mol. Data by chemical transport:ΔH°B(NdAl3Cl12,g,298) = -701,5 ± 3,0 kcal/mol; S°(NdAl3Cl12,g,298) = 215,0 ± 4,0 cal/K-mol.

Thermische Zersetzung und Lösungskalorimetrie von Ammoniumneodymiodiden / Thermal Decomposition and Solution Calorimetry of Ammonium Neodymium Iodides

2000 ◽  
Vol 55 (1) ◽  
pp. 65-73 ◽  
Author(s):  
C. Hennig ◽  
H. Oppermann
Keyword(s):  
Thermal Decomposition ◽  
Pressure Measurement ◽  
Total Pressure ◽  
Solution Calorimetry ◽  
Enthalpies Of Formation ◽  
Pressure Measurements ◽  
Heats Of Solution

The thermodynamical data of ammonium neodymium iodides (NH4)3NdI6 and (NH4)2NdI5 were derived by the determination of their decomposition equilibria by total pressure measurements. Moreover, solution calorimetry was applied. The enthalpies of formation of these phases were calculated from their heats of solution and from the enthalpies of formation and the heats of solution of N dl3 and NH4I in 4n HI (aq.) at 298 K.Data by total pressure measurement:⊿H°B(NH4)3NdI6,f,298) = -306,7 ± 4,9 kcal/mol;S°((NH4)3NdI6,f,298) = 152,8 ± 5,7 cal/K·mol;⊿H°B(NH4)2NdI5,f,298) = -260,9 ± 4,2 kcal/mol;S°((NH4)2NdI3,f,298) = 114,3 ± 4,7 cal/K·mol.Data by solution calorimetry:⊿H°B(NdI3,f,298) = -154,3 ± 2,0 kcal/mol;⊿H°B((NH4)3NdI6,f,298) = -299,6 ± 3,2 kcal/mol;⊿H°B((NH4)2NdI5,f,298) = -255,2 ± 2,8 kcal/mol.

Thermische Zersetzung und Lösungskalorimetrie von Ammoniumneodymchloriden/Thermal Decomposition and Solution Calorimetry of Ammonium Neodymium Chlorides

1998 ◽  
Vol 53 (2) ◽  
pp. 175-183 ◽  
Author(s):  
C. Hennig ◽  
H. Oppermann
Keyword(s):  
Thermal Decomposition ◽  
Pressure Measurement ◽  
Total Pressure ◽  
Solution Calorimetry ◽  
Enthalpies Of Formation ◽  
Heats Of Solution

Abstract The thermodynamical data of ammonium neodymium chlorides (NH4)2NdCl5 and NH4Nd2Cl7 were derived by the determination of their decomposition equilibria by total pres­sure measurements. Moreover, solution calorimetry was applied. The enthalpies of formation of these phases were calculated from their heats of solution and from the enthalpies of formation and the heats of solution of NdCl3 and NH4Cl.Data by total pressure measurement:ΔH°B((NH4)2NdCl5,f,298) = - 412,5 ± 3,6 kcal/mol;S°((NH4)2NdCl5 f 298) = 80,1 ± 5,8 cal/K · mol;ΔH°B(NH4Nd2Cl7,f,298) = -579,5 ± 3,5 kcal/mol;S°(NH4Nd2Cl7,f,298) 101,8 ± 5,6 cal/K mol.Data by solution calorimetry:ΔH°B(NdCl3,f,298) = -251,2 ± 0,7 kcal/mol;ΔH°B((NH4)2NdCl5,f,298) = -405,5 ± 1,0 kcal/mol;ΔH°B(NH4Nd2Cl7,f, 298) = -576,8 ± 1,7 kcal/mol.

scholarly journals Thermodynamics of Molybdenum Trioxide (MoO3) Encapsulated in Zeolite Y

2021 ◽  
Author(s):  
Xianghui Zhang ◽  
Andrew Strzelecki ◽  
Cody Cockreham ◽  
Vitaliy Goncharov ◽  
Houqian Li ◽  
...  
Keyword(s):  
Molybdenum Trioxide ◽  
Zeolite Y ◽  
Formation Enthalpy ◽  
Solution Calorimetry ◽  
Metal Species ◽  
Enthalpies Of Formation ◽  
Host Interactions ◽  
Oxide Melt ◽  
High Temperature Oxide ◽  
Temperature Oxide

Zeolites with encapsulated transition metal species are extensively applied in the chemical industry as heterogenous catalysts for favorable kinetic pathways. To elucidate the energetic insights into formation of subnano-sized molybdenum trioxide (MoO) encapsulated/confined in zeolite Y (FAU) from constituent oxides, we performed a systematic experimental thermodynamic study using high temperature oxide melt solution calorimetry as the major tool. Specifically, the formation enthalpy of each MoO/FAU is less endothermic than corresponding zeolite Y, suggesting enhanced thermodynamic stability. As Si/Al ratio increases, the enthalpies of formation of MoO/FAU with identical loading (5 Mo-wt%) tend to be less endothermic, ranging from 61.1 ± 1.8 (Si/Al = 2.9) to 32.8 ± 1.4 kJ/mol TO (Si/Al = 45.6). Coupled with spectroscopic, structural and morphological characterizations, we revealed intricate energetics of MoO – zeolite Y guest – host interactions likely determined by the subtle redox and/or phase evolutions of encapsulated MoO.

Determination of the Heat of Formation of Octafluorotoluene and Calculation of D[C6F5—F] – D[C6F5—CF3]

1973 ◽  
Vol 51 (22) ◽  
pp. 3662-3664 ◽  
Author(s):  
Michael J. Krech ◽  
Stanley James W. Price ◽  
Wayne F. Yared
Keyword(s):  
Material Balance ◽  
Combustion Method ◽  
Heat Of Formation ◽  
Enthalpies Of Formation ◽  
Direct Combustion ◽  
Fold Excess

The heat of formation of octafluorotoluene has been determined using the direct combustion method previously developed for hexafluorobenzene. As in the hexafluorobenzene case the combustion of octafluorotoluene in oxygen yields CO2, CF4, and F2. With a ten-fold excess of oxygen the CO2 to CF4 ratio is 3.85 ± 0.06. A full material balance was obtained. The value of ΔHf2980(C6F5CF3,g) = −303.2 ± 1.8 kcal mol−1 may be combined with the enthalpies of formation of C6F6, CF3, and F to give D[C6F5—F] – D[C6F5—CF3] = 55.7 ± 4.0 kcal mol−1.

Calorimetric Determination of the Enthalpies of Formation of Liquid Ni-Zr Alloys

1991 ◽  
Vol 12 (2) ◽  
pp. 141-147 ◽  
Author(s):  
I Arpshofen ◽  
R Lück ◽  
B Predel ◽  
J.F Smith
Keyword(s):  
Enthalpies Of Formation ◽  
Calorimetric Determination ◽  
Zr Alloys
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