Density and Viscosity for a Binary Mixture of Ethyl Valerate and Hexyl Acetate with 1-Pentanol and 1-Hexanol at 293.15 K, 303.15 K, and 313.15 K Nani Indraswati, Mudjijati, Filicia Wicaksana, and Herman Hindarso Department of Chemical Engineering, Widya Mandala Catholic University, Kalijudan 37, Surabaya 60114, Indonesia Suryadi Ismadji* Department of Chemical Engineering, The University of Queensland, St. Lucia, QLD 4072 Brisbane, Australia Density and viscosity for a binary mixture of ethyl valerate and hexyl acetate with 1-pentanol and 1-hexanol were measured in this experiment at three different temperatures (293.15, 303.15, and 313.15 K) and at atmospheric pressure. The measurements were carried out over the whole range of composition. Density values were used in the determination of the excess molar volume, V E , and the viscosity deviations, Δη L . The latter were fitted to the Redlich-Kister polynomial equation. Introduction In the flavor and fragrance industries, aliphatic and acrylic esters are important materials in the manufacturing processes. Several studies of the thermodynamic behavior, such as excess volume and excess enthalpy, 1-5 and physical properties 6,7 of their binary mixtures have been performed. The density and viscosity data of a binary mixture are important from practical and theoretical points of view, to understand liquid theory. However, detailed investigations of these physical properties of the esters in a binary mixture with alcohol over a wide range of temperatures and compositions are scarce in the literature. Therefore, this study was undertaken to obtain reliable density and viscosity data for binary mixtures of ethyl valerate and hexyl acetate with 1-pentanol and 1-hexanol at 293.15 K, 303.15 K, and 313.15 K. From these data, excess molar volume and the viscosity deviations were calculated. Experimental Section Materials. High purity and AR grade samples of ethyl valerate, hexyl acetate, 1-pentanol, and 1-hexanol were purchased from Merck, Germany. The purity of all the chemicals was analyzed by gas chromatography (Shi- madzu, GC-17A) using a flame ionization detector with a DB-5 column. Since the purity of all compounds was >99.6 mol %, these chemicals were used without further purifica- tion. The binary mixture samples were prepared by mass in airtight stoppered glass bottles using a Mettler Toledo AE 240 balance with a precision of (10 -5 g. The possible error of the mole fraction for each binary mixture is <(0.0001. Density Measurements. The measurements of the densities of the pure components and the binary mixtures were carried out using a Mettler Toledo density meter type DE50 with the precision 10 -5 g‚cm -3 . Prior to use, the instrument was calibrated with double-distilled water. The temperature of the measuring cell was maintained at 293.15 K, 303.15 K, and 313.15 K using Julabo refrigerated and heating circulators model F12-MD with stability up to (0.01 K. Viscosity Measurements. For the viscosity measure- ment, an automated microviscosimeter Anton Paar type AMVn, equipped with an automatic timer ((0.01 s), was used. This instrument uses the rolling ball principle according to DIN 53015 and ISO/DIS 12058, where gold- covered steel balls roll down inside an inclined, sample- filled glass capillary. The uncertainty in time in the range (0 to 250) s is <0.02 s with a resolution of (0.01 s. The temperature range of this viscosimeter is from 283.15 K * To whom correspondence should be addressed: E-mail: suryadi@ cheque.uq.edu.au. Fax: 61-7-3365 4199. Telephone: 61-7-33658389. Table 1. Comparison of Experimental Density (GL), Viscosity (ηL), and Refractive Index (nD) of Pure Liquid with Literature Values at 293.15 K, 303.15 K, and 313.15 K FL/(g‚cm -3 ) ηL/(mPa‚s) compound T/K exp lit. exp lit. ethyl valerate 293.15 0.876 80 0.8770 8 0.846 0.847 8 0.840 9 303.15 0.866 90 n.a 0.694 0.698 9 313.15 0.856 81 n.a 0.629 0.603 9 hexyl acetate 293.15 0.873 09 0.8726 10 1.078 0.860 8 1.170 10 303.15 0.863 22 0.8636 10 0.782 n.a 313.15 0.853 53 0.8546 10 0.672 n.a 1-pentanol 293.15 0.814 12 0.8144 10 4.109 4.400 9 303.15 0.807 11 0.8072 10 0.8068 11 2.933 3.202 9 2.909 10 2.961 11 313.15 0.799 78 0.8000 10 2.299 2.422 9 1-hexanol 293.15 0.818 41 0.8187 10 4.993 5.022 9 303.15 0.811 60 0.8118 10 0.8119 11 3.792 3.872 8 3.765 10 3.781 11 313.15 0.804 60 0.8048 10 2.812 2.779 9 134 J. Chem. Eng. Data 2001, 46, 134-137 10.1021/je0001431 CCC: $20.00 © 2001 American Chemical Society Published on Web 12/09/2000