Zur Kenntnis der Thermodynamik des Tellurdioxyds und seiner Umsetzung mit Schwefel

Abstract

1 ) s = fest, 1 = fliissig, g = gasformig.2) Journ. Amer. chem. SOC. 47. 356 -1925.. 3) Hezieht sich stets ebensn wie die folgenrlen (;rijl.kii nuf konstanten 1)rurk Nr. 11/1940, &r Thermodynuviik iies TelEurdioxyd.5

The Oxides and Oxyacids of Tellurium

“…From an approximate fitting of the high temperature heat content with a Debye equation, Mezaki and Margrave (94) estimated the entropy of tellurium dioxide, S°29s = 14 ± 2 eu, while an estimated value of 16.8 ± 1 eu is reported by Kubaschewski and Evans (77). A value of 17.57 cal mole-1 deg-1 has been reported for the entropy of tellurium dioxide at 25°from electrochemical data (44). Since the difference between the reported values of the entropy is quite large, the thermochemical value of 14 ± 2 eu is probably more correct than the electrochemical value.…”

“…In the range of liquid tellurium dioxide from 745 to 873°C p = 26.92 + 0.52 X 10-3 A similar equation Cp = 15.667 + 333666 X 10-3T was obtained (110) for the range 25-733°from which a value of 16.68 cal mole-1 deg-1 was calculated for 25°, and using the more accurate equation Cp = 19.655 -8.706 X 10-4 -3.97537 X 105/ 2 a value of 14.92 cal mole-1 deg-1 was calculated for 25° ( 110). A value of the molar heat capacity of 15.89 cal mole-1 deg-1 at 25°was calculated from an empirical formula relating entropy and heat capacity (44). The best value of the heat capacity of tellurium dioxide at 25°is probably 16 ± 1 cal mole-1 deg-1.…”

“…For the reaction Te(s) + 2H20(1) -* Te02(s) + 2H2(g) the value of -77.807 kcal/mole was calculated for the heat of formation of tellurium dioxide, and a value of -64.668 kcal/mole for the free energy of formation in the range 25-45° ( 44). For the same reaction, Schumann (121) found values of 298 = -64.32 kcal/mole and #298 = -77.7 kcal/mole.…”

Lattice properties ofPbX(X=S,Se,TeRomero1, Cardona2, Kremer3 et al. 2008Phys. Rev. B617391View full textAdd to dashboardCite

“…In the case of 130 Te, we first reduced 130 TeO with sulfur. 18 The synthesis was performed in argon by increasing the temperature to ∼650 o C of the chalcogen. In the sealed silica ampoule crystal growth took place by sublimation at temperatures of 750 to 850 o C under excess of the corresponding chalcogen.…”