CHEM 240Thermodynamic studies Course

for Engineering Students

King Abdul Aziz University

Jeddah KSA

Who am I?

Dr. Mohamed Abdel Salam

Assistant Professor of Physical Chemistry

• PhD in Nano Chemistry, Canada (2007)

• M Sc in Electrochemistry, Canada (2003)

• PhD in Physical Chemistry, Egypt (2001)

• M Sc in Physical Chemistry, Egypt (1994)

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How to reach me

• Faculty of Science – Chemistry

Department, Room 411.

• Email me at: masalam16@hotmail.com

masalam16@yahoo.com

• Leave a message at mail box –

Chemistry Department – third floor

• www.kau.edu.sa/mabdelsalam

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Text Book

• Any Physical Chemistry Book

• Selected textbook:• Physical Chemistry R.A.Alberty and R.J.Silby.

Physical Chemistry G.Barrow.

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Grading System

Lab work 25%

Quizzes 10%

Attendance &participation 10%

Midterm exam 15%

Final Exam 40%

Grading System

95 – 100 % A+

90 – 95 % A

85 – 89 % B+

80 – 84 % B

75 – 79 % C+

70 – 74 % C

65 – 69 % D+

60 – 64 % D

< 60 % F (Fail)

Chemistry 240 SyllabusSyllabusSyllabusSyllabus

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Topic Numb

erPeriod Title Whats is due ?

1 3 Day 3 Hour

week no.1 Introduction Kinetic theory of the gases important equations deduced from the theory

2 3 Day 3 Hour

week no.2 Van der Waals eq.and the critical states the real state eq.the chain rule.

3 3 Day 3 Hour

week no.3 Work and heat in physical chemistry Joules experiment the first law of thermodynamic solve some problems

4 3 Day 3 Hour

week no.4 cyclic integral cyclic process exact and inexact functions solve problems

5 3 Day 3 Hour

week no.5 work of compression and expansion change in state at constant volume and pressure periodic Exam.1

6 3 Day 3 Hour

week no.6 Heat capacities adiabatic process Carnote cycle heat engine solve some problems

7 3 Day 3 Hour

week no.7 Kelvin and Clauses theories Entropy and the second low of thermodynamic change in entropy

8 3 Day 3 Hour

week no.8 Entropy change in rev.process Combined first and second low Mid-term exam.

9 3 Day 3 Hour

week no.9 Entropy change in irrev.process and entropy mixing third law of thermodynamic entropy for chemical reaction solve some problems

10 3 Day 3 Hour

week no.10 Thermodynamic derivatives for closed systems Maxwells relations Effect of temperature and pressure on free energy.

11 3 Day 3 Hour

week no.11 Fugacity and free energy Fundamental equations for open system Partial molar quantity solve some problems

12 3 Day 3 Hour

week no.12 Phase equlibria water system and binary solutions second peiodic exam.

13 3 Day 3 Hour

week no.13 Miscible and immiscible binary mixtures Intoduction for electrochemistry Electrochemical cells and EMF measurements thermodynamic relations for elect

14 3 Day 3 Hour

week no.14 Activity activity coefficient ionic strength Debey-Hukel law Electrode potential chemical kinetics (first second and third order reactions).

15 2 Day 2 Hour

week no.15 Final Examination

What’s in a name?

• Thermodynamics

• thermo = heat

• dynamics = power (mechanics)

• Study of the relation between heat and mechanics

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Can we get power from the heat?

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Yes

Can we get power from the heat?

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Can we get power from the heat?

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Can we get power from the heat?

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Introduction� Physical chemistry establishes and develops:

� principles of chemistry

� concepts used to explain and interpret observations on the physical

and chemical properties of matter

� Central theme:

• systems

• states

•Processes

�Topics of physical chemistry:

othe study of the macroscopic properties of systems of many atomsor molecules

othe study of processes which such systems can undergo

othe study of the properties of individual atoms and molecules

othe study of the relationship between microscopic (atomic or molecular) properties and macroscopic properties

Main areas of physical chemistry

• Thermodynamics

• Quantum mechanics

• Statistical mechanics

• Kinetics and transport

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ice (solid) water (liquid) vapor (gas)0 oC 100 oC

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� What is the processes?

• Heating up the system; sharp transition from

solid ice to water at 0 oC and from liquid water to water vapor at 100 oC.

• The macroscopic properties changes, but there is no change in the molecules or the forces between atoms.

Example of a thermodynamic system: water, pure H2O, say 1 L at ambient pressure (1 atm)

• Can we understand these changes?

• Can we predict the transition temperature, i.e., the melting temperature Tm and the boiling temperature Tb, or the macroscopic properties of the different phases, e.g., the molar volumes, or the dependence of the transition temperatures on pressure on impurities (e.g. salt), etc.

• Can two or more different phases exist for the same external conditions?

• carbon:

• 1) diamond: transparent, colorless, hard;

• 2) graphite: black, slippery, soft;

• 3) buckminsterfullerene:

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Process

• Processes (transformations, reactions):

melting ice, evaporating water, burning methane, . .

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Process

• 1) Can it occur?

• 2) Will it occur spontaneously?

• 3) How fast will it occur?

• thermodynamics: 1) and 2); kinetics: 3)

• How can we influence a process?

• applications: reactor design, catalysts,

corrosion, . . .19

�Thermodynamics is the branch of science that predicts whether a state of some

macroscopic system will remain unchanged or will spontaneously evolve to a new state.

�Kinetics is the branch of science that deals with how long it takes for a system

to reach that new state.

�Mechanics is the branch of science that deals with the motions of small numbers

of particles.

Thermodynamics

• → Describes macroscopic properties of equilibrium systems

• → Entirely Empirical

• → Built on 4 Laws and “simple” mathematics

• 0th Law → Defines Temperature (T)

• 1st Law → Defines Energy (U) and its conservation

• 2nd Law → Defines Entropy (S)

• 3rd Law → Gives Numerical Value to Entropy

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Applications of Thermodynamics

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Definitions

• System: The part of the Universe that we choose to study

• Surroundings: The rest of the Universe

• Boundary: The surface dividing the System from the Surroundings

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Surroundings

System

Kinds of Systems

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• Open system: exchange of energy and matter

• Closed system: exchange of energy but not matter

• Isolated system: can exchange neither energy nor matter

Describing systems requires

• • A few macroscopic properties: p, T, V, n, m,

…

• • Knowledge if System is Homogeneous or

Heterogeneous

• • Knowledge if System is in Equilibrium State

• • Knowledge of the number of components

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Two classes of Properties

• Extensive: Depend on the

size of the system and will

be double if the system is

duplicated and added to

itself (n,m,V,…)

• Intensive: Independent of

the size of the system

(T,p,ρ, molar volume…) 26

Thermal equilibrium

• If two closed system with fixed volumes are

brought together (thermal contact), what will happened?

• Changes may take place in the properties of both and finally a state is reached in which there is no further change, i.e. reach

equilibrium and both system will have the same final temperature.

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The Zero’th Law of Thermodynamic

• It is concerned with thermal equilibrium between three bodies, A, B and C.

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Consequences of the Zero’th law:

• If the volume of one of these systems is held

constant, its pressure my vary over a range of values.

• If the pressure of one of these systems is held constant, its volume my vary over a range of values.

• Thus, V and P are independent thermodynamic variables.

• When one of the systems reach equilibrium at a certain P and V, all its macroscopic

properties have certain characteristic values.

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