Liquid N-pentane Research Articles

Thermodynamic properties of saturated and compressed liquid n-pentane

The results of new isochoric ( p, ϱ, T) measurements are reported for n-pentane covering the liquid range of densities from 0.42 to 0.67 g·cm −3 and pressures up to 60 MPa. Vapour-pressure measurements have been carried out at temperatures from 350 to 460 K. In addition new results for the density of saturated liquid n-pentane are presented at temperatures from 237 to 440 K.

Extrapolated ranges and stopping cross-sections for alpha particles. II. Liquid hydrocarbons; phase effect

For pt.I see ibid., vol.29, no.7, p.811-27 (1984). The stopping power and ranges of alpha particles (2.0 to 4.75 MeV) in liquid n-pentane, n-hexane and benzene have been measured by the indirect method to a precision of better than 2.5% for ranges and 4% for stopping powers. Comparison of the results with the stopping powers of these materials in gaseous phase shows that liquids have lower stopping powers than their vapours.

Speed of sound in saturated liquid n-pentane

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpeed of sound in saturated liquid n-pentaneMartin Chavez, Jose M. Palacios, and Ricardo TsumuraCite this: J. Chem. Eng. Data 1982, 27, 3, 350–351Publication Date (Print):July 1, 1982Publication History Published online1 May 2002Published inissue 1 July 1982https://doi.org/10.1021/je00029a036RIGHTS & PERMISSIONSArticle Views85Altmetric-Citations11LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (229 KB) Get e-Alerts Get e-Alerts

Vacuum ultraviolet absorption spectra of aromatic molecules in solution

The absorption spectra of benzene, naphthalene, azulene, N,N,N′,N′-tetramethyl- p-phenylenediamine (TMPD), pyrene, and fluoranthene were measured in liquid perfluoro- n-hexane (PF n-H) in the range 35 000–65 000 cm −1 and in liquid n-pentane ( n-Pt) in the range 35 000–59 000 cm −1, using a 150-μm-thick cell. The absorption spectra in PF n-H show more structure than those in n-Pt and because they are extended in the Rydberg transition region may be used to separate Rydberg from core transitions in the gaseous spectra of the molecules studied. The transmission spectra for PF n-H, n-Pt, and some of the most commonly used hydrocarbon solvents are presented also.

Photoconductivity studies in some nonpolar liquids

Measurements of the photoconductivity of liquid n-pentane, n-hexane, cyclopentane, cyclohexane, neopentane, neohexane, and tetramethylsilane induced by far UV radiation (7⩽hν⩽10 eV) have been performed. We have studied the influence of the incident photon energy, of the applied electric field strength, and of the concentration of two electron scavengers (carbon tetrachloride and perfluoromethylcyclohexane). Our results show that in going from the gas phase to the liquid phase, the ionization energy threshold values of these low dielectric constant liquids are lowered by about 1.6 eV. The introduction of an electron scavenger reduces drastically the solvent photocurrent. Our results are consistent with the quenching, by the scavenger, of a solvent expanded excited state, precursor of the geminate ion pair, and not with an epithermal electron scavenging as in high energy photon irradiation.

Effects of density and temperature on mobilities of electrons in vapors and liquids of pentane isomers: Molecular structure effects

The mobility of electrons in low density gaseous n-pentane is independent of applied electric field strength up to E/n=2 Td. The mobility in isopentane increases at E/n≳0.4 Td, and in neopentane at ≳0.2 Td. The ratio of the threshold drift velocity for electron heating to the velocity of sound, vd(threshold)/co, increases as the molecules become less spherelike. The value of the ratio in low density xenon is ∼0.7, in neopentane ∼5, isopentane ∼15, and n-pentane ≳100. The high field mobilities in neopentane and isopentane vapors seem to approach the field independent value in n-pentane. Representing the velocity dependence of the scattering cross section as σv=e/mbjv1−j, the value of 1−j increases with increasing sphericity of the molecules. Values of 1−j and σav=〈v〉/〈v/σv〉 for thermal electrons in the dilute gases at 300 K are respectively: n-pentane, 1.1, 1.3×10−15 cm2; isopentane, 1.5, 1.8×10−15 cm2; neopentane, 3.2, 4.0×10−15 cm2. The variation of (1−j) and σav with sphericity for the isomeric pentanes can be interpreted in terms of either: a) a Ramsauer–Townsend effect, the σv minimum occurring at lower v for less spherelike molecules; or b) a transient negative ion state lying near zero energy, which makes a stronger contribution to scattering from more spherelike molecules. The apparent values of (1−j) and σv increase in the high density gases, due to multibody interactions. Mobilities in the liquids n-pentane and isopentane are interpreted in terms of thermally activated electron transitions between localized and extended states. The extent of localization is greater for less spherelike molecules. Behavior in neopentane is more complex. The structure factor S (0) does not have the influence suggested earlier on electron scattering in the fluid far removed from the triple point.

On dose dependence of γ-irradiated liquidn-alkanes fragmentation products

Abstract The data on the dose dependence of light hydrocarbons radiation yields observed in liquid n-pentane γ-radiolysis can be accounted for to a high degree, assuming that a) unsaturated compounds, accumulating with dose, decrease light hydrocarbon yields in the same way as electron scavengers at very low doses; b) low molecular weight olefins content decrease due to the attachment of thermal H atoms; the radicals produced give mainly respective alkanes, thus increasing fragment alkanes yields; c) the reactions of short radicals with unsaturates do not appear significant.

Pulse radiolysis of liquid n-pentane and n-pentane-oxygen solutions. Rate constants and activation energies for second-order decay of pentyl and pentylperoxy radicals

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPulse radiolysis of liquid n-pentane and n-pentane-oxygen solutions. Rate constants and activation energies for second-order decay of pentyl and pentylperoxy radicalsL. W. Burggraf and R. F. FirestoneCite this: J. Phys. Chem. 1974, 78, 5, 508–514Publication Date (Print):February 1, 1974Publication History Published online1 May 2002Published inissue 1 February 1974https://doi.org/10.1021/j100598a010RIGHTS & PERMISSIONSArticle Views29Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (793 KB) Get e-Alerts

Permittivity increments in non-dipolar solvents due to high electric fields

Measurements of the change in relative permittivity (ΔIµ) have been made as a function of applied electric field (E) at 22°C for the non-dipolar liquids n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, cyclohexane, benzene, carbon tetrachloride and carbon disulphide. The measurements were made at fields of up to 2 × 107 V m–1, the ΔIµ being detected via the change in frequency of an oscillator as measured using a computing counter. The range of ΔIµ/E2 values obtained were from about 10 to 30 × 10–20m2V–2. The values were generally larger than could be attributed to the anisotropy of polarizability, particularly for the nearly spherical carbon tetrachloride molecule and much larger than the expected contributions due to electrostriction and the electrocaloric effect. The measured values are undoubtedly made up from a number of effects, including the Kielich local fluctuating intermolecular effects.

Ultrasonic relaxation in liquid C5-C10, C12 and C14 n-alkanes

Ultrasonic absorption has been measured in liquid n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane and n-tetradecane, over the temperature range from –40°C or the melting point to 25°C and frequency range 15 to 230 MHz. A relaxation observed in the four higher members of this series has been discussed in terms of rotational isomeric processes. The important feature of the results is that the frequency of the acoustically active conformation change decreases with increasing chain length. The variation is similar to that expected for the first normal mode of motion of a chain of damped torsional oscillators. The ratio of compressional to shear viscosities in these systems decreases with increasing chain length, again indicating that a rotational isomeric change of finite volume change is involved in both shear and compressional relaxation.

The liquid dielectric ionization chamber as a means to study mixed radiation fields

Measurements made by a dielectric liquid ionization chamber are reported. Dielectric liquids n-pentane, n-hexane, n-heptane and iso-octane were used. In particular the response of the chamber to a mixed radiation field of γ-rays and neutrons was studied. It is shown that, after previous calibration, the instrument is able to measure the contribution of the two components of the radiation field. The results of the calibration for 60Co γ-rays and for Po-Be neutrons are given.