Ethylene. The Heat Capacity from 15°K. to the Boiling Point. The Heats of Fusion and Vaporization. The Vapor Pressure of the Liquid. The Entropy from Thermal Measurements Compared with the Entropy from Spectroscopic Data

Egan, Clark J.; Kemp, J. D.

doi:10.1021/ja01286a031

Cited by 87 publications

(17 citation statements)

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“…Since the vapour pressures of ethylene become very small at low temperatures, the left part of figure 5 shows absolute pressure deviations, while the right part shows relative pressure deviations. It can be seen that for T E 160 K the p s measurements of Bigeleisen et al (11) and Egan and Kemp (12) agree with our values only near the triple-point temperature and start diverging systematically towards lower pressures for higher temperatures. The measurements of Gammon (10) for T E 160 K differ by up to Dp = 90 Pa from our values; these deviations exceed the uncertainty of Q=30 Pa= claimed for this region.…”

Section: Discussionsupporting

confidence: 79%

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Measurement and correlation of the (p, ρ,T) relation of ethylene II. Saturated-liquid and saturated-vapour densities and vapour pressures along the entire coexistence curve

Nowak

Kleinrahm

Wagner

1996

The Journal of Chemical Thermodynamics

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Comprehensive and accurate measurements of the saturated-liquid and saturated-vapour densities together with the vapour pressure of pure ethylene were carried out from T = 104 K (triple-point temperature Tt = 103.989 K) to 0.025 K below the critical temperature. The critical constants (Tc = 282.350 K, rc = 214.24 kg·m −3 , pc = 5.0418 MPa) and the isothermal compressibilities in the critical region close to the phase boundary have also been determined from these measurements. Comparisons with experimental results of previous workers are presented. Based on the new values from this work, new correlation equations for the vapour pressure, the saturated-liquid density, and the saturated-vapour density have been established.

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Section: Discussionsupporting

confidence: 79%

“…Gammon (10) 1978 27 104 to 282 0.01 to 25 Bigeleisen 1977 31 104 to 176 11.0 et al (11) Egan and Kemp (12) 1937 11…”

Section: Discussionmentioning

confidence: 99%

Measurement and correlation of the (p, ρ,T) relation of ethylene II. Saturated-liquid and saturated-vapour densities and vapour pressures along the entire coexistence curve

Nowak

Kleinrahm

Wagner

1996

The Journal of Chemical Thermodynamics

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“…Again, the intensity of the 721 cm À1 feature is substantially larger than that for C 2 D 4 adsorbed at 80 K. If the absorption cross section for this state is similar to that for other adsorbed ethylenic species, the ethylene must form multilayers on the surface. Note, however, that the vapor pressure of ethylene at 80 K is 7:3 Â 10 À4 Torr [17] and should therefore not condense onto the surface. It was also found that the heat of adsorption of the species giving rise to the 954 cm À1 feature on Pt(1 1 1) [18], assigned to p-bonded ethylene, was 40 AE 10 kJ/mol, substantially higher than the sublimation energy of ethylene, DH sub ¼ 18:3 kJ/mol [19].…”

Section: Resultsmentioning

confidence: 99%

Ethylene adsorption on Pd( 111 ) studied using infrared reflection–absorption spectroscopy

2002

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The adsorption of ethylene has been studied on clean and hydrogen-covered Pd(1 1 1) using reflection-absorption infrared spectroscopy and molecular beam methods. Using a correlation diagram, in which vibrational frequencies are plotted versus a rp parameter proposed by Stuve and Madix, shows that ethylene is substantially rehybridized on Pd(1 1 1) having a rp parameter intermediate between those of ethylene on Ni(1 1 1) and Ru(0 0 1). In contrast, when ethylene adsorbs on hydrogen-covered Pd(1 1 1), only p-bonded species are detected. An additional species appears exhibiting a characteristic frequency of 957 cm À1 when Pd(1 1 1) is cooled to $80 K and the system pressurized with $10 À5 Torr of ethylene. This species also appears on a CO-saturated Pd(1 1 1) surface. Molecular beam measurements show that its coverage reaches $1.3 ML indicating that it is due to ethylene adsorbed in the second and subsequent layers. Ó

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“…Some investigators attribute this to a premelting effect due to impurities [9,19] while others claim that in some instances these values are characteristic of the pure material [5]. As previously mentioned, the isoprene for this investigation was purified to a very high degree, but other tests indicate that isoprene may absorb moisture from the atmosphere.…”

Section: Heat Of Fusionmentioning

confidence: 78%

Entropy of isoprene from heat-capacity measurements

Bekkedahl¹,

Wood²

1937

J. RES. NATL. BUR. STAN.

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Measurements of heat capacity were made on a sample of isoprene of high purity from 20 to 300 0 K with an adiabatic vacuum-type calorimeter. At 200K the heat capacity of the crystalline material was found to be U.8 j/(mole ' degree), and with increase in temperature the heat capacity increases, following the usual type of curve for crystalline substances. At lOO°l( the heat capacity of the solid is 64.7 j/(mole· degree), and at the melting point, 126.4°l(, the heat of fusion is determined to be 4,830 ± 15 j/mole. The heat capacity of the substance increases about 60 percent during the change from solid to liquid. Above the fusion temperature the curve is characteristic of liquids, and the heat capacity attains a value of 152.6 j/(mole . degree) at 298.2°K (25°C). Utilization of the data, according to the third law of thermodynamics, yields 229.3 ± 1.0 jf (mole· degree) for the entropy of isoprene at this temperature.

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Ethylene. The Heat Capacity from 15°K. to the Boiling Point. The Heats of Fusion and Vaporization. The Vapor Pressure of the Liquid. The Entropy from Thermal Measurements Compared with the Entropy from Spectroscopic Data

Cited by 87 publications

References 0 publications

Measurement and correlation of the (p, ρ,T) relation of ethylene II. Saturated-liquid and saturated-vapour densities and vapour pressures along the entire coexistence curve

Measurement and correlation of the (p, ρ,T) relation of ethylene II. Saturated-liquid and saturated-vapour densities and vapour pressures along the entire coexistence curve

Ethylene adsorption on Pd( 111 ) studied using infrared reflection–absorption spectroscopy

Entropy of isoprene from heat-capacity measurements

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