Calorimetrie an Yttriumtrihalogeniden und Yttriumoxidhalogemden / Calorimetry of Yttrium Trihalides and Yttrium Oxyhalides

1997 ◽  
Vol 52 (3) ◽  
pp. 305-310 ◽  
Author(s):  
H. Oppermann ◽  
S. Ehrlich ◽  
C. Hennig
Keyword(s):  
Enthalpies Of Formation ◽  
Heats Of Solution

Abstract The heats of solution of Yttrium, YOCL, YOBr, YOI, YCl3, YBr3, YI3 and Y2O3 were determined in 4n HX. From those the enthalpies of formation of Yttrium Trihalides YX3 and Yttrium Oxyhalides YOX at 298 K were derived: ΔHB0(YCl3,f,298) = -240.4 ± 0.6 kcal/mol, ΔHB0(YBr3,f,298) = -202.1 ± 1.5 kcal/mol,ΔHB0(YI3,f ,298) = -147.0 ± 1.7 kcal/mol, ΔHB0(YOClf,298) = -240.2 ± 1.0 kcal/mol, ΔHB0(YOBrf,298) = -229.7 ± 2.0 kcal/mol, ΔHB0(YOIf ,298) = -208.8 ± 2.0 kcal/mol.

Untersuchungen zum ternären System Bi/Te/O, III. Bestimmung thermodynamischer Daten der ternären Verbindungen/Investigations on the Ternary System Bi/Te/O,III. Determination of Thermodynamic Data of Ternary Compounds

1999 ◽  
Vol 54 (2) ◽  
pp. 252-260 ◽  
Author(s):  
P. Schmidt ◽  
C. Hennig ◽  
H. Oppermann
Keyword(s):  
Solid State ◽  
Ternary System ◽  
Thermodynamic Data ◽  
Phase Relations ◽  
Solid State Reactions ◽  
Enthalpies Of Formation ◽  
Ternary Compounds ◽  
Heats Of Solution

The phase relations in the ternary system Bi/Te/O have been determined in previous studies by solid state reactions. Thermodynamical data have now been obtained for the pertinent equilibria. The heats of solution of Bi2O3, Bi12TeO20, Bi10Te2O19, Bi16Te5O34, Bi2TeO5, Bi2Te2O7, Bi2Te4O11 and TeCl4 were determined in 4N HCl. From these the enthalpies of formation of bismuth tellurites at 298 K have been derived:⊿H°b (Bi12TeO20, f, 298) = -901,6 ± 8 kcal/mol,⊿H°b (Bi10Te2O19, f, 298) = -856,1 ± 9 kcal/mol,⊿H°b (Bi16Te5O34, f, 298) = -1519,5 ± 17 kcal/mol,⊿H°b (Bi2TeO5, f, 298)= -222,8 ± 3 kcal/mol,⊿H°b (Bi2Te2O7, f, 298)= -299,4 ± 4 kcal/mol,⊿H°b (Bi2Te4O11, f, 298)= -448,2 ± 7 kcal/mol.

Calorimetrie an Ammoniumyttriumhalogeniden / Calorimetry of Ammonium Yttrium Halides

1997 ◽  
Vol 52 (3) ◽  
pp. 311-314 ◽  
Author(s):  
S. Ehrlich ◽  
H. Oppermann ◽  
C. Hennig
Keyword(s):  
Enthalpies Of Formation ◽  
Heat Of Solution ◽  
Heats Of Solution ◽  
Solid Phases

Abstract The heat of solution of all solid phases in the system YX3-NH4X with X = Cl, Br, I in 4n HX was investigated. The enthalpies of formation of the ammonium yttrium halides are derived from the enthalpies of formation of Y X3 and of NH4X and their heats of solution in An HX: ΔHB0(NH4Y2Cl7,f,298) = -561,5 ± 1,7 kcal/mol, ΔHB0((NH4)3 YCl6,f,298) = -474,5 ± 1,3 kcal/mol,ΔHB0((NH4)3YBr6,f,298) = -400,8 ± 2,6 kcal/mol, ΔHB0((NH4)3YI6,f,298) = -291,9 ± 3,0 kcal/mol.

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 Ammoniumsamariumchloriden/Thermal Decomposition and Solution Calorimetry of Ammonium Samarium Chlorides

1997 ◽  
Vol 52 (12) ◽  
pp. 1517-1525 ◽  
Author(s):  
C. Hennig ◽  
H. Oppermann
Keyword(s):  
Thermal Decomposition ◽  
Pressure Measurement ◽  
Total Pressure ◽  
Solution Calorimetry ◽  
Enthalpies Of Formation ◽  
Pressure Measurements ◽  
Heats Of Solution ◽  
Solid Phases

Abstract We determined the decomposition equilibria of ammonium samarium chlorides (NH4)2SmCl5 and NH4Sm2Cl7 by total pressure measurements and derived their thermody­ namical data from the decomposition functions. The enthalpies of formation were compared with the results of the solution calorimetry. The heats of solution of all solid phases in the system SmCl3-NH4Cl and of Sm2O3 were measured in 4n HCl. The enthalpies of formation of ammonium samarium chlorides were derived from the enthalpies of formation of SmCl3 and of NH4Cl and their heats of solution.Data by total pressure measurementΔH°B((NH4)2SmCl5,f,298) =-407,7 ± 2,9 kcal/mol;S0((NH4)2SmCl5,f,298) = 84,0 ± 4,5 cal/K-mol;ΔH°B((NH4)Sm2Cl7,f,298) = -576,8 ± 3,4 kcal/mol;S°(NH4Sm2Cl7,f,298) = 98,1 ± 5,5 cal/K-mol.Data by solution calorimetryΔH°B(SmCl3,f,298) = -248,1 ± 0,8 kcal/mol;ΔH°B((NH4),SmCl5,f,298) = -404 ,3 ± 1,1 kcal/mol;ΔH°B(NH4Sm9Cl7,f,298)= -572,3 ± 1,8 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.

Heats of Solution of Some Sodium and Potassium Salts in Water and in Water-Methanol Mixtures

1992 ◽  
Vol 57 (11) ◽  
pp. 2227-2234 ◽  
Author(s):  
Ján Benko ◽  
Oľga Vollárová
Keyword(s):  
Transfer Functions ◽  
Enthalpies Of Solution ◽  
Potassium Salts ◽  
Solvent Interactions ◽  
Heats Of Solution ◽  
Solvent Molecules ◽  
Sodium And Potassium

The enthalpies of solution ∆Hs0 were determined for NaSCN, KSCN, NaBrO3, KBrO3, NaClO3, KClO3, NaIO4, KMnO4, KNO2 and NaNO2 in water-methanol mixtures. The transfer functions ∆Ht0 of the salts and anions were calculated based on the extrathermodynamic TPTB assumption. The ∆Ht0 values of the anion obtained from the sodium and potassium salts were compared. The differences observed, particularly at higher concentrations of the cosolvent, are discussed with respect to the interactions between the solvent molecules and the solute-solvent interactions.

The Molar Heats of Solution of Boric Oxide and Boric Acid1

1951 ◽  
Vol 73 (2) ◽  
pp. 579-581 ◽  
Author(s):  
Ervin R. Van Artsdalen ◽  
Keith P. Anderson
Keyword(s):  
Boric Oxide ◽  
Heats Of Solution
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