Excess molar enthalpies of {diethyl oxalate + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} at T = (288.2, 298.2, 313.2, and 328.2) K and p = 101.3 kPa

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Highlights

  • The excess molar enthalpies for four binary systems of diethyl oxalate + alcohols were determined.

  • The densities of the diethyl oxalate at different temperature were measured.

  • The excess molar enthalpies increase with temperature and the molecular size of the alcohols.

  • The experimental data were correlated by two local-composition models (NRTL and UNIQUAC).

Abstract

A flow-mixing isothermal microcalorimeter was used to measure excess molar enthalpies for four binary systems of {diethyl oxalate + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} at T = (288.2, 298.2, 313.2, and 328.2) K and p = 101.3 kPa. The densities of the diethyl oxalate at different temperature were measured by using a vibrating-tube densimeter. All systems exhibit endothermic behaviour over the whole composition range, which means that the rupture of interactions is energetically the main effect. The excess molar enthalpies increase with temperature and the molecular size of the alcohols. The experimental results were correlated by using the Redlich–Kister equation and two local-composition models (NRTL and UNIQUAC).

Introduction

Diethyl oxalate (DEO, CASRN: 95-92-1) is an intermediate which is widely used in chemical synthesis, medicine, printing, dyeing, electronics industry and so on [1], [2], [3], [4]. The synthesis method [5], [6] and thermodynamic properties [7], [8], [9], [10], [11] of DEO have been developed and studied during the past years.

Until now, no excess molar enthalpies (HmE) data of systems containing (DEO + C1 to C4) alcohols could be found in the literature. In this paper, the HmE values for four binary systems of {DEO + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} were determined by using a flow-mixing isothermal microcalorimeter at T = (288.2, 298.2, 313.2, and 328.2) K and p = 101.3 kPa. The experimental data were correlated by using the Redlich–Kister equation and two local composition models: the NRTL model and the UNIQUAC model.

Section snippets

Materials

Diethyl oxalate (guaranteed grade, purity >99.0%) was purchased from Shanghai Jiachen Chemical. Methanol (HPLC grade, purity >99.8%) and 2-propanol (HPLC grade, purity >99.5%) were provided by Tianjin Siyou Fine Chemical. Ethanol (HPLC grade, purity >99.7%) was purchased from Sinopharm Chemical Reagent. 1-Propanol (HPLC grade, purity >99.5%) was provided by Tianjin Saifu, China. The source and purity of solvents used in this work were listed in table 1. Before used, all chemicals were degassed

Results and discussion

The HmE values of the four binary systems have been listed in TABLE 3, TABLE 4, TABLE 5, TABLE 6. As examples, HmE values of {DEO (1) + methanol (2)} in table 3 and {DEO (1) + alcohols (2)} at T = 298.15 K and 101.3 kPa are plotted in figure 1 and figure 2, respectively.

The experimental values of the HmE are correlated by using the Redlich–Kister equation and two local composition models (NRTL and UNIQUAC). The expressions of HmE derived from the GmE model were developed through the Gibbs–Helmholtz

Conclusions

In this work, the excess molar enthalpies of four binary systems {DEO + (methanol, + ethanol, + 1-propanol, and + 2-propanol)} were measured at T = (288.2, 298.2, 313.2, 328.2, 338.2, and 348.2) K and p = 101.3 kPa. For the same system, the HmE value increases as the temperature increases. At the same temperature, the HmE value increases as the length and the branch chains increase. For all the systems, the HmE values fitted by Redlich–Kister equation and the NRTL model are better than those fitted by

References (18)

  • X.Z. Jiang et al.

    Appl. Catal. A Gen.

    (2001)
  • K.W. Cheng et al.

    Fluid Phase Equilib.

    (2001)
  • R. Zhang et al.

    Thermochim. Acta

    (2005)
  • R.H. Wiley et al.

    J. Am. Chem. Soc.

    (1958)
  • E. Campaigne et al.

    J. Org. Chem.

    (1958)
  • X. Creary

    J. Org. Chem.

    (1987)
  • S. Gorog

    Anal. Chem.

    (1970)
  • P.W. Jewel et al.

    J. Am. Chem. Soc.

    (1931)
  • I.C. Pan et al.

    J. Chem. Eng. Data

    (2000)
There are more references available in the full text version of this article.

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