Heat capacities of liquid hydrocarbons. Estimation of heat capacities at constant pressure as a temperature function, using additivity rules

1977 ◽  
Vol 22 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Menachem Luria ◽  
Sidney W. Benson
Keyword(s):  
Constant Pressure ◽  
Heat Capacities ◽  
Liquid Hydrocarbons ◽  
Temperature Function ◽  
Additivity Rules

The volumetric and thermochemical properties of aqueous solutions of L-valine, L-leucine, and L-isoleucine at 288.15, 298.15, 313.15, and 328.15 K

1994 ◽  
Vol 72 (6) ◽  
pp. 1489-1494 ◽  
Author(s):  
Michelle M. Duke ◽  
Andrew W. Hakin ◽  
Robert M. McKay ◽  
Kathryn E. Preuss
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aqueous Solutions ◽  
Constant Pressure ◽  
Heat Capacities ◽  
Thermochemical Properties ◽  
Acid System ◽  
Standard State ◽  
Apparent Molar Heat Capacities ◽  
Fitting Procedures

Densities and volumetric heat capacities have been measured for aqueous solutions of L-valine, L-leucine, and L-isoleucine at 288.15, 298.15, 313.15, and 328.15 K. These data have been used to calculate apparent molar volumes, [Formula: see text] and apparent molar heat capacities, [Formula: see text] which in turn have been used to obtain standard state volumes, [Formula: see text] and standard state heat capacities, [Formula: see text] for each aqueous amino acid system. Helgeson, Kirkham, and Flowers equations, for neutral organics in water, have been used to model the calculated standard state volumes and heat capacities of the amino acids as a function of temperature at constant pressure. The results of our fitting procedures may be used to predict the behaviour of [Formula: see text] and [Formula: see text] for the selected amino acid systems outside of the temperature range utilised in this investigation.

Ultrasonic velocities, compressibilities, and heat capacities of water + tetrahydrofuran mixtures at 298.15 K

1979 ◽  
Vol 57 (9) ◽  
pp. 1006-1010 ◽  
Author(s):  
Osamu Kiyohara ◽  
Patrick J. D'Arcy ◽  
George C. Benson
Keyword(s):  
Molecular Interactions ◽  
Constant Pressure ◽  
Heat Capacities ◽  
Ultrasonic Velocities ◽  
Excess Heat ◽  
Excess Heat Capacities ◽  
Flow Microcalorimeter ◽  
Thermal Expansivities ◽  
Isentropic And Isothermal Compressibilities ◽  
Pulse Echo

Ultrasonic velocities and volumetric heat capacities at constant pressure were measured at 298.15 K for water + tetrahydrofuran mixtures over the whole concentration range using pulse–echo–overlap equipment and a flow microcalorimeter respectively. Isentropic and isothermal compressibilities and heat capacities at constant pressure and at constant volume were derived from the results in combination with the results of previous studies of thermal expansivities and excess volumes. The significance of the excess compressibilities and excess heat capacities is discussed in terms of molecular interactions.

Ideal gas processes – and two ideal gas case studies too

2018 ◽  
Author(s):  
Dennis Sherwood ◽  
Paul Dalby
Keyword(s):  
Case Studies ◽  
Constant Pressure ◽  
Ideal Gas ◽  
Heat Capacities ◽  
Carnot Cycle ◽  
State Function ◽  
Ideal Gases ◽  
First Case ◽  
The Ideal

This chapter brings together, and builds on, the results from previous chapters to provide a succinct, and comprehensive, summary of all key relationships relating to ideal gases, including the heat and work associated with isothermal, adiabatic, isochoric and isobaric changes, and the properties of an ideal gas’s heat capacities at constant volume and constant pressure. The chapter also has two ‘case studies’ which use the ideal gas equations in broader, and more real, contexts, so showing how the equations can be used to tackle, successfully, more extensive systems. The first ‘case study’ is the Carnot cycle, and so covers all the fundamentals required for the proof of the existence of entropy as a state function; the second ‘case study’ is the ‘thermodynamic pendulum’ – a system in which a piston in an enclosed cylinder oscillates to and fro like a pendulum under gravity, in both the absence, and presence, of friction.

Apparent molar heat capacities and volumes of aqueous solutions of several 1:1 electrolytes at elevated temperatures

1986 ◽  
Vol 64 (5) ◽  
pp. 926-931 ◽  
Author(s):  
Preet P. S. Saluja ◽  
Jacques C. LeBlanc ◽  
Harold B. Hume
Keyword(s):  
Heat Capacity ◽  
Aqueous Solutions ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Constant Pressure ◽  
Solubility Limit ◽  
Heat Capacities ◽  
Apparent Molar Heat Capacities ◽  
Flow Microcalorimeter ◽  
Good Agreement

The results of heat capacity (Cp) and density (d) measurements at 0.6 MPa and in the temperature range 298.15–373.15 K are presented for several 1:1 electrolytes in water. The flow microcalorimeter and densimeter used for these measurements were modificatons of the room-temperature designs. Data were obtained over concentrations ranging from 0.02 to 1.0 mol kg−1 (or to the solubility limit, whichever was lower). The heat capacity of a solution relative to that of water was measured with a precision of ±0.1 mJ K−1 g−1 at all temperatures. The density of a solution relative to that of water was measured with a precision of ±5 μg cm−3. These Cp and d results were used to calculate the apparent molar heat capacities, [Formula: see text], and volumes, [Formula: see text], at 298.15, 323.15, 348.15, and 373.15 K, at a constant pressure of 0.6 MPa. These results are in good agreement with available literature data.

Thermodynamic properties of binary mixtures containing ketones. VIII. Heat capacities and volumes of some n-alkanone + n-alkane mixtures at 298.15 K

1984 ◽  
Vol 62 (5) ◽  
pp. 949-953 ◽  
Author(s):  
Jean-Pierre E. Grolier ◽  
George C. Benson
Keyword(s):  
Thermodynamic Properties ◽  
Composition Dependence ◽  
Constant Pressure ◽  
Excess Molar Volumes ◽  
Heat Capacities ◽  
Free Energies ◽  
Volumetric Heat Capacity ◽  
Text Data ◽  
Excess Molar Heat Capacities ◽  
Heat Capacity Measurements

Excess molar volumes, [Formula: see text], and excess molar heat capacities at constant pressure, [Formula: see text], have been obtained for some n-alkanone + n-alkane mixtures at 298.15 K from density and volumetric heat capacity measurements using liquid-flow techniques. The [Formula: see text] data are much more accurate than those estimated from the temperature dependence of other thermodynamic properties (excess free energies and/or excess enthalpies). The rather unusual composition dependence of the excess heat capacities — two minima, or W-shape curves — is most likely due to cooperative induced conformational molecular "arrangements" in these mixtures.

scholarly journals (P,ρ,T) properties of 1-octyl-3-methylimidazolium tetrafluoroborate

2018 ◽  
Vol 83 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Javid Safarov ◽  
Aygul Namazova ◽  
Astan Shahverdiyev ◽  
Egon Hassel
Keyword(s):  
Equation Of State ◽  
Speed Of Sound ◽  
Isothermal Compressibility ◽  
Constant Pressure ◽  
Pressure Coefficient ◽  
Heat Capacities ◽  
Thermal Pressure ◽  
Average Percent Deviation ◽  
Wide Range ◽  
Isentropic Exponent

(p,?,T) data of 1-octyl-3-methylimidazolium tetrafluoroborate [OMIM][BF4] over a wide range of temperatures, from 278.15 to 413.15 K, and pressures, p, up to 140 MPa are reported with an estimated ?0.01?0.08 % experimental relative average percent deviation (APD) in the density. The measurements were performed using an Anton Paar DMA HPM vibration tube densimeter. (p,?,T) Data for [OMIM][BF4] was fitted and the parameters of the applied equation were determined as a function of pressure and temperature. After a thorough analysis of literature values and validity of the used equation of state, various thermophysical properties, such as isothermal compressibility, isobaric thermal expansibility, differences in isobaric and isochoric heat capacities, thermal pressure coefficient, internal pressure, heat capacities at constant pressure and volume, speed of sound and isentropic exponent at temperatures in the range 278.15?413.15 K and pressures p up to 140 MPa were calculated.

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