Thermochemistry of Silver Bromate

1971 ◽  
Vol 49 (3) ◽  
pp. 523-524 ◽  
Author(s):  
L. M. Gedansky ◽  
L. G. Hepler
Keyword(s):  
Solubility Product ◽  
Standard Entropy ◽  
Heat Of Solution ◽  
Heats Of Solution ◽  
Calorimetric Measurements

Calorimetric measurements of the heat of solution of AgBrO3(c) in NH3(aq) have been combined with earlier data on heats of solution of AgNO3(c) in water and in NH3(aq) to yield ΔH0 = 11.78 ± 0.11 kcal mol–1 for AgBrO3(c) = Ag+(aq) + BrO3−(aq). Combination of this value with ΔG0 = 5.83 kcal mol–1 from the solubility product gives ΔS0°= 19.96 cal deg–1 mol–1 for the standard entropy of solution of AgBrO3(c) at 298 °K.

The heats of solution of alcohols in water

1969 ◽  
Vol 22 (2) ◽  
pp. 347 ◽  
Author(s):  
DM Alexander ◽  
DJT Hill
Keyword(s):  
Enthalpy Of Solution ◽  
Heat Of Solution ◽  
Quadratic Dependence ◽  
Heats Of Solution ◽  
Low Concentrations

A new calorimeter has been developed and the enthalpy of solution of methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, and 2- methylpropan-2-ol, in water to low concentrations, measured between 5� and 35�. In all cases, the results can be adequately represented by a quadratic dependence of heat of solution on temperature. The results have been compared qualitatively with the data for the hydrocarbons.

Untersuchungen zum quasibinären System Bi2Te3/BiCl3/Investigations on the Pseudobinary System Bi2Te3/BiCl3

1999 ◽  
Vol 54 (2) ◽  
pp. 234-238 ◽  
Author(s):  
U. Petasch ◽  
C. Hennig ◽  
H. Oppermann
Keyword(s):  
Total Pressure ◽  
Ternary Phase ◽  
Heat Of Formation ◽  
Standard Entropy ◽  
Pressure Measurements ◽  
Pressure Data ◽  
Heat Of Solution ◽  
Pseudobinary System ◽  
Vapor Pressure Data ◽  
X Ray

The phase diagram of the pseudobinary sytem Bi2Te3/BiCl3 was investigated by DTA, total pressure measurements, and X-ray phase analysis. Only BiTeCl exists as a ternary phase in this system. The compound melts incongruently at 430 °C. The heat of formation and the standard entropy of BiTeCl were calculated from vapor pressure data:ΔH°B (BiTeCl, f, 298) = (-39,5 ± 1,6) kcal/mol; S° (BiTeCl, f, 298) = (34,4 ± 2,7) cal/K· mol.The heat of formation of BiCl3 was determined on the basis of the heat of solution of BiCl3 and Bi2O3, and the heat of formation of Bi2O3: ΔH°B (BiCl3, f, 298) = (-95,9 ± 0,9) kcal/mol.

The equilibria of calcium and phosphate ions with the micellar calcium phosphate in cow's milk

1979 ◽  
Vol 46 (2) ◽  
pp. 343-346 ◽  
Author(s):  
Richard L. J. Lyster
Keyword(s):  
Calcium Phosphate ◽  
Crystalline Form ◽  
Cow’S Milk ◽  
Salt Solutions ◽  
Heat Of Solution ◽  
Phosphate Ions ◽  
Calorimetric Measurements ◽  
Ionic Equilibria ◽  
Wide Range ◽  
Computer Calculations

SUMMARYCalorimetric measurements of the heat of solution of micellar Ca phosphate suggest that this material more closely resembles OH-apatite than amorphous Ca phosphate or any other crystalline form. Preliminary computer calculations of the ionic equilibria of milk salt solutions indicate that, over a wide range of pH and temperature, such solutions are supersaturated with respect to OH-apatite and to various other Ca salts under certain conditions.

Ligand field splitting energies of the hexaamminecobalt(II) ion and the hexaamminenickel(II) ion measured by a calorimetric method

1970 ◽  
Vol 48 (14) ◽  
pp. 2177-2181 ◽  
Author(s):  
Badri Muhammad ◽  
J. W. S. Jamieson
Keyword(s):  
Close Agreement ◽  
High Energy ◽  
Calorimetric Method ◽  
Ligand Field ◽  
Maximum Difference ◽  
Kcal Mole ◽  
Heat Of Solution ◽  
Field Splitting ◽  
Heats Of Solution ◽  
Splitting Energy

Various normal lower ammines and high-energy modifications of the lower ammines of cobalt(II) sulfate and nickel(II) sulfate have been prepared and the heats of solution in dilute ammonia have been measured for both types. For each of these ammine systems the maximum difference in heat of solution, expressed as kcal/mole of each heptaammine, between the high-energy and the normal salts has been found to be in close agreement with the ligand field splitting energy of the hexaamminemetal(II) ion.

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.

The entropy of zinc chromite (ZnCr2O4)

2004 ◽  
Vol 68 (3) ◽  
pp. 515-522 ◽  
Author(s):  
S. Klemme ◽  
J. C. van Miltenburg
Keyword(s):  
Heat Capacity ◽  
Low Temperature ◽  
Adiabatic Calorimetry ◽  
Standard Entropy ◽  
Capacity Curve ◽  
Heat Capacity Curve ◽  
Calorimetric Measurements ◽  
Temperature Heat ◽  
Low Temperature Heat Capacity ◽  
Zinc Chromite

AbstractThe low-temperature heat capacity of zinc chromite (ZnCr2O4) was measured between 6.5 K and 400 K using adiabatic calorimetry, and some thermochemical functions (CP(T),S(T), S°298,H(T)-H(0)) were derived from the results. The standard entropy (S°298= 128.6±0.3 J mol-1K-1) for zinc chromite was calculated from the results. Our calorimetric measurements indicate one extremely large anomaly in the heat capacity curve at ∼12.3 K which is related to the cubic-tetragonal transition in ZnCr2O4.

The Heats of Solution and Related Thermodynamic Properties of Sodium Chlorate in Water and Water–Dioxane Mixtures

1971 ◽  
Vol 49 (2) ◽  
pp. 217-224 ◽  
Author(s):  
A. N. Campbell ◽  
O. Bhatnagar
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Activity Coefficients ◽  
Direct Method ◽  
Sodium Chlorate ◽  
Saturated Solution ◽  
Heat Of Solution ◽  
Heats Of Solution ◽  
Tentative Explanation ◽  
A Direct Method

The heats of solution of sodium chlorate in water, and in several water-dioxane mixtures, have been determined experimentally at concentrations of salt ranging from 0.01 molal to saturation. For the dilute region, a direct method was used but for the concentrated range the method was that of diluting the saturated solution. The free energy decreases due to dilution have been calculated from previously determined activity coefficients. Using these data, the entropy changes have been evaluated.The graph of heat of solution vs. concentration of sodium chlorate passes through a minimum for the solutions more concentrated in dioxane, but not for water and weak dioxane mixtures. A tentative explanation of this is offered.

CALCULATION OF HEATS OF SOLUTION IN SATURATED MIXED ELECTROLYTES

1960 ◽  
Vol 38 (1) ◽  
pp. 161-170
Author(s):  
Y. Iyengar
Keyword(s):  
Temperature Coefficient ◽  
Activity Coefficients ◽  
Solubility Product ◽  
Mixed Electrolytes ◽  
Heats Of Solution ◽  
Harned's Rule

Theoretical equations have been derived for calculating heats of solutions of an electrolyte in its saturated system comprising one or more electrolytes. These expressions involve the application of "Harned's rule" concerning activity coefficients in mixed electrolytic solutions to an extension of van't Hoff's equation dealing with the temperature coefficient of solubility product in non-ideal systems. The commonly occurring case of mixed electrolytic pairs has been considered in detail. Application of theoretical equations to calculate the heats of solutions KCl, NaCl, and KNO3 in the saturated systems KCl–NaCl–H2O and KCl–KNO3–H2O is briefly discussed.

THE HEATS OF SOLUTION AND SPECIFIC HEATS OF RHOMBIC SULPHUR IN CARBON DISULPHIDE: THE SURFACE ENERGY OF SOLID RHOMBIC SULPHUR

1935 ◽  
Vol 13b (5) ◽  
pp. 280-288 ◽  
Author(s):  
A. R. Williams ◽  
F. M. G. Johnson ◽  
O. Maass
Keyword(s):  
Particle Size ◽  
Surface Energy ◽  
Carbon Disulphide ◽  
Heat Of Solution ◽  
Specific Heats ◽  
Heats Of Solution

The heats of solution of rhombic sulphur in carbon disulphide were measured over the concentration range 6 to 17% of sulphur and at 20° and 25 °C., and the specific heats of these solutions were calculated. The apparatus designed for these measurements is described. By measuring the heat of solution of finely divided sulphur and its particle size, the surface energy of solid rhombic sulphur is estimated.

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