Excess molar volumes and molar enthalpies in the binary mixtures of {x1CH3CHClCH2Cl+x2CH3(CH2) n−1OH} (n=1 to 4) at T=298.15K

Autor: Moon-Gab Kim, Dipak Sen
Rok vydání: 2009
Předmět:
Zdroj: Korean Journal of Chemical Engineering. 26:806-811
ISSN: 1975-7220
0256-1115
DOI: 10.1007/s11814-009-0134-6
Popis: The excess molar volumes V and excess molar enthalpies H at T=298.15 K and atmospheric pressure for the binary systems {x1CH3CHClCH2Cl+x2CH3(CH2) n−1OH} (n=1 to 4) have been determined from density measurements by using a digital vibrating-tube densimeter and an isothermal calorimeter with flow-mixing cell, respectively. The 1-alkanols are methanol, ethanol, 1-propanol and 1-butanol. The V values of the binary mixtures increase with chain length of the 1-alkanols, resulting in entire negative V values for methanol, ‘S-shaped’ for ethanol, being nega- tive at low and positive at high mole fraction of 1,2-dichloropropane, and entire positive V values for both 1-propanol and 1- butanol. The H values for all systems show an endothermic effect (positive values), which exhibits a regular increase in magnitude when the number of -CH2- group in 1-alkanols is progressively increased and maximum values of H varying from 741 J·mol−1 (methanol) to 1,249 J·mol−1 (1-butanol) around x1=0.63−0.72. The experimental results of both H and V were fitted to Redlich-Kister equation to correlate the composition dependence. The experimental H data were also used to test the suitability of the Wilson, NRTL, and UNIQUAC models. The correlation of excess enthalpy data in these binary systems using UNIQUAC model provides the most appropriate results except for the system containing methanol.
Databáze: OpenAIRE
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