Excess enthalpies and heat of esterification reaction in ethanol + acetic acid + ethyl acetate + water system at 313.15 K Alexandra Golikova 1 • Nikita Tsvetov 1,2,3 • Artemiy Samarov 1 • Maria Toikka 1 • Irina Zvereva 1 • Maya Trofimova 1 • Alexander Toikka 1 Received: 27 November 2018 / Accepted: 10 June 2019 Ó Akade ´miai Kiado ´, Budapest, Hungary 2019 Abstract The excess enthalpies for ethanol ? acetic acid ? ethyl acetate ? water system in the chemically equilibrium states are determined with the C80 calorimeter (Setaram) equipped with membrane mixing cells at 313.15 K and atmospheric pressure. The quaternary system exhibited positive values of the excess enthalpies over the entire range of mole fractions. The heat of esterification reaction is calculated on the base of data obtained for heat effects in the mixture, and it was found to be - 3.6 ± 0.2 kJ mol -1 . The correlation of the data was carried out using NRTL model and Redlich–Kister equation. Keywords Thermochemistry Á Excess enthalpy Á Heat of esterification reaction Á Calorimetry Introduction The study of thermochemical behavior of reacting systems in the chemical equilibrium is an important task from both basic and applied point of view. In particular, thermo- chemical data are necessary for the design of the processes of reactive distillation and extraction [1–3]. The increase in the number of publications in Journal of Thermal Analysis and Calorimetry related to the determination of the thermal effects of various processes (formation, mixing, evapora- tion, etc.) in the period from 2017 [4–6] to 2018 [7–15] confirms the rise of interest in this subject. The aim of present work is to continue the study of excess thermodynamic properties in the system with reac- tion of ethyl acetate synthesis presented in our previous article [7]. The study of thermodynamic properties, espe- cially excess molar enthalpy, is applicable to quantify the deviation from the ideal of thermodynamic functions of mixtures and is also very important for understanding of molecular interactions in solutions. In addition, the knowledge of excess molar enthalpies and other thermo- dynamic parameters give an opportunity to extend the temperature range thermodynamically correctly in the studies of complex processes and states, for example, to determine the equilibrium properties at temperatures close to the boiling point from the one-temperature data. In spite of this, studies of coupled processes are generally focused on the data on vapor–liquid and chemical equilibrium [16–21], while thermochemical studies are limited. Cou- pled processes are applied in a lot of modern technological schemes, being one of the most perspective ways of development of energy- and resource-saving technologies. Some authors have investigated the excess thermody- namic properties of some binary and ternary subsystems of the quaternary system acetic acid–ethanol–ethyl acetate– water [3, 22–25]. Excess enthalpies for binary, ternary and quaternary systems which consist of esterification reaction reactants are also discussed in recent works of our scientific group [7, 26–28]. The study of the enthalpy of chemical reaction of ethyl acetate synthesis had been carried out by some authors [29, 30]. & Nikita Tsvetov tsvet.nik@mail.ru 1 Department of Chemical Thermodynamics and Kinetics, St. Petersburg State University, Universitetskiy Prospect 26, Peterhof, Saint Petersburg, Russia 198504 2 Tananaev Institute of Rare Element and Mineral Chemistry and Technology, Kola Research Center Russian Academy of Sciences, «Academic Town», 26a., Apatity, Murmansk Region, Russia 184209 3 Murmansk Arctic State University, A Branch in Apatity, Lesnaja Str. 29, Apatity, Murmansk Oblast, Russia 184209 123 Journal of Thermal Analysis and Calorimetry https://doi.org/10.1007/s10973-019-08488-y