Heat Capacities of Some Alkyl Acetates at 295-323 K

1997 ◽  
Vol 62 (10) ◽  
pp. 1527-1532 ◽  
Author(s):  
Václav Svoboda ◽  
Kornelia Gottmanová ◽  
Vladimír Hynek ◽  
Bohumír Koutek
Keyword(s):  
Experimental Data ◽  
Linear Function ◽  
Atmospheric Pressure ◽  
Heat Capacities ◽  
Group Additivity ◽  
Temperature Range ◽  
Alkyl Acetates

Molar heat capacities Cp,m at constant atmospheric pressure have been determined with a typical uncertainty of about 0.3% for eight liquid alkyl acetates H(CH2)nOCOCH3 (n = 6-12, 14), over the temperature range 295-323 K. The Cp,m values were found to be a linear function of temperature. A comparison of experimental data with those predicted by the group additivity method demonstrated a rather limited capability of the additivity scheme to predict correctly the Cp,m values for higher (n > 10) homologues in the series.

scholarly journals Thermal Conductivity of Steam at Atmospheric Pressure

1969 ◽  
Vol 11 (4) ◽  
pp. 392-401 ◽  
Author(s):  
T. J. S. Brain
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Steady State ◽  
Atmospheric Pressure ◽  
Concentric Cylinder ◽  
Temperature Range ◽  
Steady State Method ◽  
New Correlation ◽  
Paper Work ◽  
State Method

In this paper work carried out by the author to measure the thermal conductivity of steam at atmospheric pressure in the temperature range 100-700°C is reported. This work was undertaken in view of the discrepancies which exist in the experimental data at atmospheric pressure. In particular, the serious differences which exist at the high temperatures between the results of Russian experimenters, who give higher values than those given by American and German workers, needed investigation. Utilizing two concentric cylinder cells an absolute steady state method has been used to measure the thermal conductivity of steam in the temperature range 100-700°C, at atmospheric pressure, with a probable accuracy estimated to be within ± l·5-±2 per cent. The results obtained confirm Russian observations at the higher temperatures and it is hoped that these results will help finally to resolve the inconsistencies in the experimental data. A fresh assessment of all the experimental data is given by the author where arguments in favour of both the lower and higher atmospheric lines are discussed. A new correlation of experimental data has been undertaken and a reduction in the tolerances put on the equation defining the atmospheric line from ±3 per cent in the range 100-400°C and ±4 per cent in the range 400-700°C to ±2 per cent over the complete range 100-700°C is now recommended.

Absolute Viscosity of Air down to Cryogenic Temperatures and up to High Pressures

1973 ◽  
Vol 15 (4) ◽  
pp. 266-270 ◽  
Author(s):  
B. Latto ◽  
M. W. Saunders
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Atmospheric Pressure ◽  
High Pressures ◽  
The Other ◽  
Cryogenic Temperatures ◽  
Temperature Range ◽  
Absolute Viscosity ◽  
Correlating Equations ◽  
Better Than

The absolute viscosity of gaseous air was determined experimentally for the general pressure and temperature range 100–15 000 kPa and 90–400 K respectively, using a series capillary transpiration-type viscometer which has been developed by the authors. The accuracy of the experimental data is believed to be better than ± 1 per cent. Two general correlating equations, one for atmospheric pressure and the other for medium high pressure (i.e., densities up to 400 kg/m3), have been obtained.

scholarly journals Thermochemical properties of the Fe-analogue of cryolite, Na3FeF6

2007 ◽  
Vol 5 (2) ◽  
pp. 508-515
Author(s):  
Ivan Nerád ◽  
Eva Mikšíková
Keyword(s):  
Experimental Data ◽  
Solid Solution ◽  
High Temperature ◽  
Heat Capacities ◽  
Drop Calorimetry ◽  
Continuous Series ◽  
Thermochemical Properties ◽  
Temperature Dependent ◽  
Crystalline Phases ◽  
Temperature Range

AbstractRelative enthalpies for low-and high-temperature modifications of Na3FeF6 and for the Na3FeF6 melt have been measured by drop calorimetry in the temperature range 723–1318 K. Enthalpy of modification transition at 920 K, δtransH(Na3FeF6, 920 K) = (19 ± 3) kJ mol−1 and enthalpy of fusion at the temperature of fusion 1255 K, δfusH(Na3FeF6, 1255 K) = (89 ± 3) kJ mol−1 have been determined from the experimental data. Following heat capacities were obtained for the crystalline phases and for the melt, respectively: C p(Na3FeF6, cr, α) = (294 ± 14) J (mol K)−1, for 723 = T/K ≤ 920, C p(Na3FeF6, cr, β) = (300 ± 11) J (mol K)−1 for 920 ≤ T/K = 1233 and C p(Na3FeF6, melt) = (275 ± 22) J (mol K)−1 for 1258 ≤ T/K ≤ 1318. The obtained enthalpies indicate that melting of Na3FeF6 proceeds through a continuous series of temperature dependent equilibrium states, likely associated with the production of a solid solution.

Vapour-liquid equilibrium in the isobutyl formate-isobutyl alcohol and n-butyl formate-isobutyl alcohol systems at atmospheric pressure

1979 ◽  
Vol 44 (12) ◽  
pp. 3501-3508 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Fourth Order ◽  
Atmospheric Pressure ◽  
Isobutyl Alcohol ◽  
Liquid Equilibrium ◽  
The Third

Isobaric vapour-liquid equilibria in the isobutyl formate-isobutyl alcohol and n-butyl formate-isobutyl alcohol systems have been measured at atmospheric pressure. A modified circulation still of the Gillespie type has been used for the measurements. The experimental data have been correlated by means of the third- and fourth-order Margules equations.

Heat capacities of liquid 2,3,6-trimethylpyridine, 2,4,6-trimethylpyridine and 3-methoxypropionitrile within the range of temperatures of 300 to 328 K

1991 ◽  
Vol 56 (12) ◽  
pp. 2786-2790 ◽  
Author(s):  
Václav Svoboda ◽  
Milan Zábranský
Keyword(s):  
Temperature Interval ◽  
Atmospheric Pressure ◽  
Liquid State ◽  
Adiabatic Calorimeter ◽  
Heat Capacities

Molar heat capacities of 2,3,6-trimethylpyridine, 2,4,6-trimethylpyridine and 3-methoxypropionitrile in the liquid state were measured at the constant atmospheric pressure in the temperature interval of 300.60 to 328.35 K. The static type of adiabatic calorimeter was used for the measurements.

Substituent effects on the thermodynamic functions of ionization of metasubstituted anilinium ions

1968 ◽  
Vol 21 (4) ◽  
pp. 939 ◽  
Author(s):  
PD Bolton ◽  
FM Hall
Keyword(s):  
Linear Function ◽  
Thermodynamic Functions ◽  
Substituent Effects ◽  
Negative Slope ◽  
Hammett Equation ◽  
Reaction Parameter ◽  
Reaction Series ◽  
Acidity Constants ◽  
Temperature Range ◽  
Relationship Of

Thermodynamic acidity constants of the meta-methoxyanilinium, meta- chloroanilinium, meta-bromoanilinium, and meta-iodoanilinium ions have been measured spectrophotometrically over the temperature range 5-50� and those of the meta-nitroanilinium ion over the temperature range 5-60�. The thermodynamic functions of ionization, ΔG25, ΔH25, ΔS25, and ΔCp,25, have also been calculated for each ion. For a series of seven meta-substituted anilinium ions the acidity constants show close obedience to the Hammett equation over the temperature range 10-50� with the reaction parameter p being a precise linear function of 1/T. The same reaction series also shows a well-defined isoequilibrium relationship of negative slope.

Transformation of 1-Butene over Synthetic Zeolites

1992 ◽  
Vol 57 (4) ◽  
pp. 869-881 ◽  
Author(s):  
Italo Ferino ◽  
Roberto Monaci ◽  
Vincenzo Solinas ◽  
Lucio Forni ◽  
Antonio Rivoldini ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Continuous Flow ◽  
Liquid Mixture ◽  
Isomerization Reaction ◽  
Reaction Conditions ◽  
Title Reaction ◽  
Y Zeolites ◽  
Temperature Range ◽  
Flow Microreactor ◽  
Synthetic Zeolites

The behaviour of several zeolites as catalysts for the title reaction has been investigated by means of a continuous flow microreactor. Runs performed at atmospheric pressure indicated that at 423 K the completely protonic forms of the zeolites catalyze just the isomerization reaction. In the case of Y zeolites, oligomerization occurs only over the partially decationated samples, in the temperature range between 373 and 423 K and W/F between 0.2 and 22 gcath/g1-but, to an extent which depends on the reaction conditions. Most of the catalysts were tested also under pressure (4.05 MPa) at 423 K. The protonic forms of Y and ZSM-5 zeolites seem promising catalysts in terms of both conversion and selectivity to oligomers. The 1-olefins account for 30% of the entire olefinic mixture. The octenes, which account for 70% of the liquid mixture, are mostly formed of dimethylhexenes. Trimers are also formed during the reaction and, in the very particular case of H[B]ZSM-5, tetramers are produced.

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