ARTICLE pubs.acs.org/jced
Partial Molar Volumes of Selected Aliphatic Alcohols at Infinite Dilution in Water at Temperatures T = (278 to 573) K and Pressures up to 30 MPa Lukas Simurka, Ivan Cibulka,* and Lubomír Hnedkovsky Department of Physical Chemistry, Institute of Chemical Technology, Technicka 5, 166 28 Prague, Czech Republic
bS Supporting Information ABSTRACT: Density data for dilute aqueous solutions of four aliphatic alcohols (2,2-dimethylpropane-1-ol, 2-methylpropane-1,3diol, 2,2-bis(hydroxymethyl)propane-1-ol, 2,2-bis(hydroxymethyl)butane-1-ol) and one ether alcohol (3,3,7,7-tetrakis(hydroxymethyl)-5-oxanonane) were obtained using both the Anton Paar DSA 5000 vibrating-tube densimeter and the laboratorymade flow densimeter. They are presented together with partial molar volumes at infinite dilution (standard molar volumes) calculated from the measured data. The measurements were performed at temperatures T = (278 to 573) K and at pressures up to p = 30 MPa. Trends in homologous series are discussed, and the group additivity scheme proposed recently is applied to the solutes investigated.
’ INTRODUCTION Recently a group contribution method1 was designed for the estimation of partial molar volumes at infinite dilution (standard molar volumes) of organic solutes in water. Group and structural contributions covering a wide range of temperature from (298 to 573) K and pressures up to 30 MPa were evaluated using data28 measured in our laboratory for aqueous aliphatic derivatives comprising one or two oxygen-containing functional groups (OH, O, >CO). The predictive abilities of the method were examined using a limited number of experimental data available in the literature for extended ranges of temperature and pressure. This examination revealed, however, that intramolecular interactions may occur among multiple functional groups which affect the standard molar volume. This was clearly observed on linear polyhydric alcohols with hydroxyl groups residing on the neighboring carbon atoms (ethane-1,2-diol, propane-1,2-diol, butane-2,3-diol, propane-1,2,3-triol, pentane1,2,3,4,5-pentanol). Similar effects were indicated by data for solutes with a globular structure derived from 2,2-dimethylpropane (neopentane), namely, 2,2-dimethylpropane-1,3-diol and 2,2-bis(hydroxymethyl)propane-1,3-diol, but a quantitative description of these effects was impossible due to lack of data for other derivatives of this series. Data presented in this work are thus complementary to those available from our previous measurements. Figure 1 shows the structures of the solute molecules investigated here along with three more solutes the data of which have been already published (propane-1,3-diol,4 2,2-dimethylpropane-1,3-diol,6 2,2-bis(hydroxymethyl)propane-1,3-diol6). The arrows between the formulas indicate a particular series of the solutes. Present new data for aqueous 2,2-dimethylpropane1-ol and 2,2-bis(hydroxymethyl)propane-1-ol make the series of alcohols derived from 2,2-dimethylpropane complete. Data for 2-methylpropane-1,3-diol fill the gap between propane-1,3diol4 and 2,2-dimethylpropane-1,3-diol.6 The molecule of 2,2bis(hydroxymethyl)butane-1-ol is derived from that of 2, r 2011 American Chemical Society
Figure 1. Structures of solute molecules.
2-bis(hydroxymethyl)propane-1-ol by adding one methylene group. Finally, a large molecule of the fifth solute, 3,3,7,7tetrakis(hydroxymethyl)-5-oxanonane, is composed of two structures of 2,2-bis(hydroxymethyl)butane-1-ol combined together by the ether-oxygen atom; that is, the hypothetical reaction between two molecules of 2,2-bis(hydroxymethyl) butane-1-ol produces one molecule of water and one molecule of 3,3,7,7-tetrakis(hydroxymethyl)-5-oxanonane. Present new data are also significant for the further development of the group contribution concept applicable over wide ranges of temperature and pressure since one solute only (2,2-dimethylpropane-1,3-diol) Special Issue: Kenneth N. Marsh Festschrift Received: May 31, 2011 Accepted: July 7, 2011 Published: July 28, 2011 4564
dx.doi.org/10.1021/je200527t | J. Chem. Eng. Data 2011, 56, 4564–4576
Journal of Chemical & Engineering Data which incorporates the quaternary carbon atom (carbon atom bonded to four other carbon atoms, >C
