Physical chemistry for mathematicians in tasks and questions: educational manual 9786010415706

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AL-FARABI KAZAKH NATIONAL UNIVERSITY

M. G. Murzagaliyeva А. К. Zhusupova А. S. Tusupbekova

PHYSICAL CHEMISTRY FOR MATHEMATICIANS IN TASKS AND QUESTIONS Educational manual Stereotypical publication

Аlmaty «Qazaq university» 2020

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UDC 544 (075.8) LBC 24.5 я 73 M 96 Recommended by Academic Council of the Faculty of Chemistry and Chemical Technology and Editorial and Publishing Council of al-Farabi KazNU (protocol №11 06.11.2015)

Reviewer Doctor of Chemical sciences, professor S.M. Tazhibaeva

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Murzagaliyeva M.G. Physical chemistry for mathematicians in tasks and questions: educational manual / M.G. Murzagaliyeva, А.К. Zhusupova, А.S. Tusupbekova. – Ster. pub. – Almaty: Qazaq university, 2020. – 100 p. ISBN 978-601-04-1570-6 Textbook is of physical chemistry is designed for students mathematical specialties of the university. It outlines the fundamentals of chemical thermodynamics, the theory of chemical equilibrium, the doctrine of the electromotive forces and the electrical conductivity of solutions, chemical kinetics. Учебное пособие по физической химии предназначено для студентов математических специальностей университета. В нем изложены основы химической термодинамики, теории химического равновесия, учение об электродвижущих силах и электропроводности растворов, химической кинетики.

UDC 544 (075.8) LBC 24.5 я 73 © Murzagaliyeva M.G., Zhusupova А.К., Tusupbekova А.S., 2020 © Al-Farabi KazNU, 2020

ISBN 978-601-04-1570-6

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INTRODUCTION

Physical chemistry – the science lying at the junction of chemistry and physics, studies the relationship of chemical and physical phenomena. Chemical reactions are always accompanied by varied physical changes: during the flow of most of them there is an allocation or absorption of heat; when operating galvanic cells due to chemical of reactions generates an electric current is, an electric current in the substances may occur chemically converted; under the action of light occur relatively simple chemical reactions used in photography, as well as complex processes of photosynthesis, many chemical processes are accompanied by the release of light. Physical chemistry uses the fundamental laws of physics and the results of physical and chemical experiments to study the properties of substances, identify patterns of chemical reactions and the relationship of external influences on the system to ongoing chemical changes in it. The occurrence of physical chemistry as a section of chemical science connect with a name M.V. Lomonosov. According to his the definition of «Physical chemistry is a science on the basis for explaining provisions and experiments of physics that occur in mixed bodies during chemical operations». The tasks of physical chemistry are the study and prediction capabilities and depth of chemical reactions, the regularities their occurrence over time, depending on external conditions and on the basis data on the properties and structure of molecules. A variety of objects and phenomena studied in physical chemistry, led to the division of this discipline into a number of large sections, some of which now have an independent scientific implications and are treated as separate training course. 3

Chemical thermodynamics. This section is studied energetics of chemical reactions, mutual transformations different types of energy, as well as the laws of chemical and phase equilibria. Electrochemistry. This section includes topics such as electrolysis, galvanic cells, chemical sources of electricity and electrochemical corrosion. In them is studied the relationship of chemical reactions and electrical phenomena. Also included are the doctrine of the properties of electrolyte solutions and questions of electrochemical kinetics (kinetics and mechanisms of electrochemical reactions). Chemical kinetics. In this section examines the dependence of the rate of chemical processes on the properties of reacting substances and reaction conditions, and their mechanisms. This teaching guide is designed for students of mathematical specialties university. It outlines fundamentals the chemical thermodynamics doctrine of chemical equilibrium, the doctrine of electromotive forces and the electrical conductivity of solutions, chemical kinetics.

1. BRIEF ABSTRACT OF LECTURES

1.1. Thermodynamics Thermodynamic system – the body or group of bodies that are in interaction, mentally or really separate from the environment. System may be homogeneous (homogeneous consist of one phase) and heterogeneous (inhomogeneous consist of two or more phases). If the system not exchanging with the environment neither substance nor energy, it is called isolated. System which exchanges energy with the environment, but does not exchange substance, is closed. If between the system and the environment, and the exchange of matter and energy – have an open system. The collection of all physical and chemical properties of the system is characterized by its thermodynamic state. All quantities characterizing any macroscopic properties of this system – this status parameters (temperature, volume, pressure, concentration, etc.). Any change in the thermodynamic state of the system (changes at least one state parameter) is a thermodynamic process. Changing the state of the system can occur under different conditions, so distinguished: 1) The equilibrium and non-equilibrium processes. Equilibrium processes – a process passing through the continuous series of equilibrium states. Nonequilibrium processes – a process flow after which the system can not be returned to its initial state. 2) Reversible and irreversible processes. Reversible processes – a process in the course of which the system returns to its initial state without the environment were are any changes. Otherwise the processes are irreversible. 5

3) Spontane- ous and nonspontaneous processes. Spontane-ous – processes that occur by themselves do not require energy from outside and brings the system to equilibrium. Nonspontaneous – processes require energy from outside. We note are some private types of processes: а) isothermal (T = const); b) isobaric (p = const); c) isochoric (V = const); d) adiabatic (no heat exchange between the system and the environment); d) isobaric-isothermal (p = const, T = const); e) isochoric-isothermal (V = const, T = const). Measure of the ability of the system to do work is energy. For energy of the system in thermodynamics adopted its internal energy (U) – the sum of kinetic and potential energy of all the particles that make up the system. In the transition from one state to another quantitative change in internal energy is equal to: ΔU =U2−U1 (1) Work (W) and heat (Q) – are two possible forms of the transfer of energy from one system to another. In the case of the energy is transmitted through a coherent, regulated- movement of particles. Work is positive (W>0), if it is done by the system against external forces, and negative (W 0), if the heat supplied to the system (called an endothermic process) and negative (Q