Excess Thermodynamic Functions of<i>n</i>-Hexane + Toluene: Application of Flory's Theory

Malakondaiah, K.; Subbarangaiah, K.; Subrahmanyam, S. V.

doi:10.1080/00319109108030632

Cited by 10 publications

(5 citation statements)

References 14 publications

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“…Shraiber, 37 Aicart et al, 39 Garbajosa et al, 40 Diaz Pena et al, 41 and Gamboa et al 43 reported data obtained by direct measurement of the change in volume with respect to pressure at fixed temperature using piezometers. Freyer et al, 33 Jacobson, 34 Rajagopal et al, 36 Reddy et al, 38 Tamura et al, 42 and Malakondaiah et al 44 determined the isothermal compressibility using an acoustic technique. This method consists of the measuring speed of sound and density in order to determine first the isentropic compressibility using eq 1.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Toluene was chosen for this study because its volumetric properties have been investigated by many groups, and there are many available data of compressibility at ambient pressure in the open literature. − Moreover, some high pressure data already exist in the temperature range investigated. − Finally, several correlations − have been developed for representing density as a function of pressure, and therefore they allow for calculating compressibility over an extended range of pressure. Thirteen sources of data have been used for comparison at atmospheric pressure.…”

Section: Resultsmentioning

confidence: 99%

“…Green ▲, Tyrer; red ■, Freyer et al; black −, Jacobson; black *, Richard and Rogers; red ◊, Rajagopal et al. ; yellow ⧫, Shraiber; black □, Reddy et al; black ●, Aicart et al; blue +, Garbajosa et al; black ○, Diaz Pena et al; blue △, Tamura et al; red ×, Gamboa et al; blue −, Malakondaiah et al; and black −·–·–, expanded uncertainty.…”

Section: Resultsmentioning

confidence: 99%

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Computation of Liquid Isothermal Compressibility from Density Measurements: An Application to Toluene

Daridon

Bazile

2018

J. Chem. Eng. Data

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A computation method was developed for estimating the compressibility and its uncertainty from density measurements carried out from atmospheric pressure to 100 MPa. For that purpose, first the ability of 19 equations for fitting density data and for calculating the isothermal compressibility was investigated. Among the equations of state tested, only 6 equations were selected for their suitability for deriving density data in the pressure range investigated. Then, a procedure for evaluating the combined standard uncertainty associated with the determination of the isothermal compressibility from the derivation of density data was tested. Finally, a numerical method was proposed for estimating the isothermal compressibility and its uncertainty from a limited number of experimental density data by considering a Monte Carlo procedure. As an example, the proposed numerical procedure was applied to liquid toluene. With this aim in mind, the density of liquid toluene was measured up to 100 MPa in the temperature range of 293.15–343.15 K by using a U-shape oscillating tube density meter.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Computation of Liquid Isothermal Compressibility from Density Measurements: An Application to Toluene

Daridon

Bazile

2018

J. Chem. Eng. Data

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“…Free volume is manifested macroscopically as the isothermal compressibility T defined as Figure 9, prepared with literature data, [59][60][61][62][63][64][65][66][67][68][69][70] shows that T is highly correlated with the Doolittle relative free volume for the three alkanes in this study.…”

Section: Discussionmentioning

confidence: 99%

“…The compressibilities in Figs. 9 and 10 for the measurement temperatures are based on exponential curve fits generated from literature compressibility data [59][60][61][62][63][64][65][66][67][68][69][70] at various temperatures. In the case of hexane, no compressibility data were found in the literature for temperatures below 273 K, which is the range in which half of the spectra for this solvent were taken.…”

Section: Discussionmentioning

confidence: 99%

Nitroxide spin exchange due to re-encounter collisions in a series of n-alkanes

Kurban

Perić

Bales

2008

The Journal of Chemical Physics

100

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Bimolecular collisions between perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-l-oxyl molecules in three alkanes have been studied by measuring the electron paramagnetic resonance ͑EPR͒ spectral changes induced by spin exchange. We define an "encounter" to be a first-time collision followed by a series of re-encounters prior to the diffusing pair's escaping each other's presence. The present work stems from a recent proposal ͓B. L. Bales et al., J. Phys. Chem. A 107, 9086 ͑2003͔͒ that an unexpected linear dependence of the spin-exchange-induced EPR line shifts on spin-exchange frequency can be explained by re-encounters of the same probe pair during one encounter. By employing nonlinear least-squares fitting, full use of the information available from the spectral changes allows us to study encounters and re-encounters separately. The encounter rate constants appear to be dominated by hydrodynamic forces, forming a common curve for hexane, decane, and hexadecane when plotted against T / , where is the shear viscosity. Unexpectedly, encounters are not dependent on the ratio = a / a s , where a and a s are the van der Waals radii of the nitroxide probe and the solvent, respectively. It is argued that the near coincidence of the resulting encounter rate constant with the hydrodynamic prediction is likely due to a near cancellation of terms in the general diffusion coefficient. Thus, the semblance of hydrodynamic behavior is coincidental rather than intrinsic. In contrast, the mean times between re-encounters do depend on the relative sizes of probe and solvent. For hexane at lower temperatures, the Stokes-Einstein equation apparently describes re-encounters well; however, at higher temperatures and for decane and hexadecane, departures from the hydrodynamic prediction become larger as becomes smaller. This is in qualitative agreement with the theory of microscopic diffusion of Hynes et al. ͓J. Chem. Phys. 70, 1456 ͑1979͔͒. These departures are well correlated with the free volume available in the solvent; thus, the mean times between re-encounters form a common curve when plotted versus the free volume. Because free volume is manifested macroscopically by the isothermal compressibility, it is expected and observed that the re-encounter rate also forms a common curve across all three solvents when plotted with respect to compressibility. The existence of a common curve for alkanes raises the prospect of using EPR to determine the compressibility of substances such as fossil fuels and biological membranes.

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Physical Properties of the Ternary System Toluene + n-Hexane + Cyclohexane at 298.15 K: Experimental and Modeling Study

Aliaj,

Hernández,

Zeqiraj

et al. 2023

Int J Thermophys

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Excess Thermodynamic Functions ofn-Hexane + Toluene: Application of Flory's Theory

Cited by 10 publications

References 14 publications

Computation of Liquid Isothermal Compressibility from Density Measurements: An Application to Toluene

Computation of Liquid Isothermal Compressibility from Density Measurements: An Application to Toluene

Nitroxide spin exchange due to re-encounter collisions in a series of n-alkanes

Physical Properties of the Ternary System Toluene + n-Hexane + Cyclohexane at 298.15 K: Experimental and Modeling Study

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