Scientia Publishing House – Sapientia Hungarian University of Transylvania

Fizikai kémiai laboratóriumi gyakorlatok és számítások [Laboratory Manual of Physical Chemistry]

The Laboratory Manual of Physical Chemistry is designed to provide the practical support of the physical chemistry lectures. In addition to setting specific theoretical knowledge, students are invited to discover the basic experimental processes, the apparatus, and the way of analysis of the physical chemistry and the related measurement technique, while they develop the practical skills required in the field. The manual is primarily designed for Food Engineering and Environmental Engineering students. Physical chemistry requires solid mathematical knowledge, including differential and integral calculus, wherefore the first part of the manual includes a synthesis lesson in mathematics.

The manual presents six practical laboratory activities, each with a brief theoretical introduction, followed by the aim and course of the experiment as well as the processing of the results. The first practical activity entitled Connections between Electrical Conductivity, Concentration, and Temperature has the aim to establish numerical expression and graphical representation by pursuing the equivalent conductivity value according to concentration, the conductivity cell constant, the electrical conductivity of the various solutions according to the concentration and temperature, specific and molar conductivity, and conductivity activation energy. The second problem, entitled Determination of Dissolution Heat of Salts by Means of a Temperature Variation Calorimeter, aims at determining the heat of hydration of anhydrous sodium acetate by measuring the dissolving heat of the anhydrous salt and the crystal hydrate by applying Hess’s law. The third problem is called Determination of Liquid-Vapour Equilibrium by Static Method, Calculation of Latent Heat of Vaporization and Vaporization Entropy, the purpose of which is to determine the vapour pressure of an organic liquid (diethyl ether) at different temperatures, the molar latent heat of vaporization over a measured temperature range, and the variation of the molar entropy of vaporization at ambient temperature.

The fourth issue addressed is called Measuring the Decrease in Solidification Temperature of the Diluted Solutions and Determining the Cryoscopy Constant of the Solvent, the aim of which is to estimate the material constant of solvents (low molar solidification temperature, cryoscopy constant) and determining therefore the molar mass. The fifth problem, entitled Determination of the Viscosity of Liquids by Concentration and Temperature, addresses the viscosity variation according to these two parameters (concentration and temperature). The sixth issue focuses on The Kinetics of Ethyl Acetate Saponification Reaction, the purpose of which is to determine the constant of the rate of reaction (hydrolysis) of the ethyl acetate and the reaction rate as well as the reaction activation energy by measuring the reaction rate at two temperature values. The manual continues with the presentation of several calculation exercises related to the studied matter, namely fluids and gas mixtures, phase transitions, chemical equilibrium, and reaction kinetics. The methodological structure of the manual, based on the succession of theoretical elements, experiments, and exercises, is designed to help students in the individual study of physical chemistry.