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1

O siłach napędowych w przyrodzie : koncepcje, interpretacje, nieporozumienia

Orlik Marek

Wiadomości Chemiczne

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2023

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[Z] 77, 1-2

1--34

EN

Prepared for presentation within the Didactic Section of Polish Chemical Society, the study summarizes selected problems and concepts of teaching the basics of chemical reaction energetics as part of chemical undergraduate studies. The following problems are discussed: 1) indication of misunderstandings related to the definition of standard states in thermodynamics, with particular emphasis on the unfortunate assignment of the temperature of 298.15 K as "standard temperature", 2) problems with the interpretation of entropy as a "measure of disorder", with a recommendation regarding for understanding entropy as a measure of the number of ways to distribute the total energy of the system between the available degrees of freedom of motions, in terms of the quantum representation, i.e. the energy characteristics of a substance through sequences of energy levels, 3) a proposal to introduce the issue of thermodynamic driving forces of a chemical reaction based on the characteristics of the water evaporation process under different conditions, which favors the distinction of any reaction driving force from its standard driving force, as well as the distinction of such forces for isochoric and isobaric systems, both one- and multi-component, (4) the necessity to take into account the entropy of mixing of reagents to deepen the understanding of changes in the driving force of the reaction on the way to the state of chemical equilibrium, and 5) various interpretations of the influence of temperature on the equilibrium composition of the reacting system (Le Chatelier-Braun rule), with a recommendation for molecular interpretation, showing the role of differences in energies and sequences of energy levels of reactants and products for the value and direction of changes of the equilibrium constants of the reaction with temperature, taking into account also the principles of statistical thermodynamics. An additional aim of the article is to emphasize the importance of elementary mathematical education for mastering the basic laws governing the course of physicochemical processes, as well as for true understanding of chemistry, in general.

2

Komplementarność fizycznych i chemicznych praw zachowania w aspekcie układów elektrolitycznych

Michałowski T.

Wiadomości Chemiczne

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2007

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[Z] 61, 7-8

625-640

EN

The charge, concentration and electron balances are closely related to other, more elementary rules of conservation of a matter in a closed system, separated from the environment by diathermal walls. The conservation rules can be formulated for the elements, electrons and protons. Among others, the generalised electron balance (GEB) concept presented and applied in some author's papers [1-7, 14-16] is derived from the elementary rules of conservation and exemplified by some batch and dynamic (titration) systems of a different degree of complexity. Some elementary rules of conservation are interdependent. This interdependency of the resulting balances and formulation of the set of independent relationships will be considered with the help of some examples, where the complex nature of the system, exemplified by the formation of aqua-complexes by both ionic and neutral species, will also be taken into account. Among others, the dynamic system is exemplified by titration of KIO_3 + HCl + H_2SeO_3 + HgCl_2 with ascorbic acid (C6H8O6). The degree of complexity of this system is evidenced by more than 40 equilibrium constants involved in the related balances.

3

Zagadnienia termodynamiki, kinetyki i inżynierii reaktorowej w obliczeniach technologicznych.

Szarawara J.

Archiwum Ochrony Środowiska

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1998

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Vol. 24, no. 4

15-33

PL

W referacie tym przedstawiono najważniejsze zagadnienia termodynamiki chemicznej, kinetyki formalnej i inżynierii reaktorowej stosowane w obliczeniach technologicznych. Szczególnie podkreślono znaczenie równań stanu, funkcji residualnych, współczynników aktywności ciśnieniowej, składy równowagowego. Omówiono metody modelowania kinetyki procesów heterogenicznych, kontaktowych oraz podstawy obliczeń reaktorowych. Przedstawione zależności mają znaczenie ogólne, są ważne dla analizy procesów chemicznych w technologii chemicznej, jak również w ochronie środowiska, szczególnie w ochronie atmosfery.

EN

The paper deals with the most important problems of chemical thermodynamics, formal kinetics and reactor engineering applied in chemical technology calculations. Special stress has been put on the importance of equations of state, residual function, the coefficients of pressure-activity (fugacity) and equilibrium compositions. Methods of modelling the kinetics of heterogenous and contacting processes as well as the foundation of reactor calculations have been discussed. The presented relations are of general significance, both the analysis of chemical reactions in chemical technology and environmental protection, particularly the protection of the atmosphere.