Entropy and the Second and Third Laws of Thermodynamics

Size: px
Start display at page:

Download "Entropy and the Second and Third Laws of Thermodynamics"

Transcription

1 CHAPTER 5 Entropy and the Second and Third Laws of Thermodynamics Key Points Entropy, S, is a state function that predicts the direction of natural, or spontaneous, change. Entropy increases for a spontaneous change in an isolated system. Variation of S with P, V, and T: conditions for spontaneity 1

2 The Universe Has a Natural Direction of Change First law of thermodynamics, U = q + w, dictates energy conservation of a process. It does not specify the direction of the change. Spontaneous process: natural transformation that will occur with a high probability, and is consistent with common sense Entropy is a measure of the number (W) of quantum states accessible to a macroscopic system with a given energy, S = k lnw (with k being the Boltzmann s constant) Entropy of an isolated system is maximized at equilibrium Heat Engines and the Second Law of Thermodynamics The concept of S arose as 19 th century scientists attempted to maximize the work output of an engine. Such a heat engine is represented below involving an ideal gas confined in a piston and cylinder assembly that is in contact with a hot reservoir (T hot ) and a cold sink (T cold ) 2

3 Conversion Asymmetry Work (e.g., electrical work) may be converted to heat at 100% efficiency. What is the maximum efficiency of heat converted into work? Maximum work output in an isothermal expansion occurs in a reversible process. Thus, the efficiency of a reversible engine is an upper bound to the efficiency of a real engine. The reversible engine converts heat into work by exploiting the spontaneous tendency of heat to flow from a hot reservoir to a cold sink. Cycle of a Reversible Heat Engine Two isothermal processes + two adiabatic processes Heat is taken up by the engine in the first step and released to the surroundings in the third step Work is done on the surroundings in the first two steps and on the system in the last two steps Carnot cycle 3

4 Nicolas Léonard Sadi Carnot Carnot (1 June August 1832) was a French military engineer and physicist, often described as the "father of thermodynamics". Carnot Cycle 4

5 Carnot Cycle -q ab = w cycle + q cd. That is, not all heat withdrawn from the higher temperature reservoir is converted to work done by the system (engine) on the surroundings The efficiency of the reversible Carnot engine Second Law of Thermodynamics Kevin-Planck formulation: it is impossible for a system to undergo a cyclic process whose sole effects are the flow of heat into the system from a heat reservoir and the performance of an equal amount of work by the system on the surroundings Cannot be constructed 5

6 Indicator Diagram For an engine to produce work, the area of the cycle in a P-V diagram must be greater than zero Carnot Cycle 6

7 Introduction of Entropy, S Because the cyclic integral of is zero, this quantity must be the exact differential of a state function, which is defined as entropy (S) Change of Entropy S is a state function S must be calculated along a reversible path For an irreversible path, S must be calculated for a reversible process that proceeds between the same initial and final states corresponding to the irreversible process For a reversible isothermal expansion/compression 7

8 Ideal Gas undergoes a reversible change of T Constant V Constant P V i, T i V f, T f P i, T i P f, T f S for Phase Change 8

9 S for an Arbitrary Process - real gases, solids, and liquids V i, T i V f, T f P i, T i P f, T f Using S to Calculate the Natural Direction of a Process in an Isolated System Heat gained by the left = lost by the right Because T 1 > T 2, if q P > 0, S < 0 If q P < 0, S > 0 The process in which S increases is the direction of natural change in an isolated system 9

10 Direction of Change For any irreversible process in an isolated system, there is a unique direction of spontaneous change: S > 0 for the spontaneous process S < 0 for the opposite or nonspontaneous direction of change S = 0 only for a reversible process. In a quasi-static reversible process, there is no direction of spontaneous change because the system is proceeding along a path, each step of which corresponds to an equilibrium state S > 0 is a criterion for spontaneous change only if the system does not exchange energy in the form of heat or work with its surroundings S and U In an isolated system, U cannot be created or destroyed (energy conservation) In an isolated system, if any process occurs, it is by definition spontaneous and therefore S can be created ( S > 0), but not destroyed. The universe is expanding 10

11 Clausius Inequality Consider the first law in which only P-V work is involved, which is valid for both reversible and irreversible processes If the process is reversible Which is valid for both reversible and irreversible processes because U is a state function, as long as there are no phase transformations or chemical reactions, and only P-V work involved. Clausius Inequality If P P external > 0, the system will spontaneously expand, and dv > 0 If P P external < 0, the system will spontaneously contract, and dv > 0 In both cases, (P P external )dv > 0 The equal sign hold only for a reversible process 11

12 Clausius Inequality For any irreversible process in an isolated system, S > 0 This will be used to define two new state functions, the Gibbs free energy (G) and Helmhotz free energy (A), which predict the direction of change in process for which the system interacts with the surroundings (Chapter 6) S is a state function, so Change of Entropy in the Surroundings The statement that a process is spontaneous if S for the system is positive is true only for an isolated system In general, a system is interacting only with the part of the universe that is very close. One can combine the system with this part of the universe into an interacting composite system that is isolated from the rest of the universe This part of the surroundings is a thermal reservoir at a fixed T (because of its large mass) The criterion for spontaneous change is S total = S + Ssurroundings > 0, which defines a unique direction of time 12

13 Change of Entropy in the Surroundings If the system is surrounded by adiabatic walls, q surroundings = 0 If the surroundings are at constant V, q surroundings = U surroundings If the surroundings are at constant P, q surroundings = H surroundings The amount of heat entering the surroundings is independent of the path; and is the same whether the transfer occurs reversibly or irreversibly Absolute Entropy and Third Law of Thermodynamics Third Law of Thermodynamics: the entropy of a pure, perfectly crystalline substance (element or compound) is zero at zero Kelvin 13

14 Third Law of Thermodynamics In a perfect crystal, individual atoms are indistinguishable, exchanging the positions of two atoms does not lead to a new state. That is, there is only one state at zero Kelvin, and S = klnw = kln1 = 0 This allows the calculation of absolute entropy at temperature T Absolute Entropy S m (gas) > S m (liquid) > S m (solid) S m increases with the size of the molecule because the number of degrees of freedom increases with the number of atoms S m (solid) is larger for weekly bound solids than for strongly bound solids at low and moderate temperatures 14

15 Standard State in Entropy Calculation For an ideal gas at constant T, Choose P i = P = 1 bar, Entropy Change in Chemical Reactions is equal to the difference in the entropies of products and reactants Temperature dependence 15

Chapter 3. The Second Law Fall Semester Physical Chemistry 1 (CHM2201)

Chapter 3. The Second Law Fall Semester Physical Chemistry 1 (CHM2201) Chapter 3. The Second Law 2011 Fall Semester Physical Chemistry 1 (CHM2201) Contents The direction of spontaneous change 3.1 The dispersal of energy 3.2 The entropy 3.3 Entropy changes accompanying specific

More information

Reversibility, Irreversibility and Carnot cycle. Irreversible Processes. Reversible Processes. Carnot Cycle

Reversibility, Irreversibility and Carnot cycle. Irreversible Processes. Reversible Processes. Carnot Cycle Reversibility, Irreversibility and Carnot cycle The second law of thermodynamics distinguishes between reversible and irreversible processes. If a process can proceed in either direction without violating

More information

Atkins / Paula Physical Chemistry, 8th Edition. Chapter 3. The Second Law

Atkins / Paula Physical Chemistry, 8th Edition. Chapter 3. The Second Law Atkins / Paula Physical Chemistry, 8th Edition Chapter 3. The Second Law The direction of spontaneous change 3.1 The dispersal of energy 3.2 Entropy 3.3 Entropy changes accompanying specific processes

More information

Chapter 12. The Laws of Thermodynamics

Chapter 12. The Laws of Thermodynamics Chapter 12 The Laws of Thermodynamics First Law of Thermodynamics The First Law of Thermodynamics tells us that the internal energy of a system can be increased by Adding energy to the system Doing work

More information

Lecture 2 Entropy and Second Law

Lecture 2 Entropy and Second Law Lecture 2 Entropy and Second Law Etymology: Entropy, entropie in German. En from energy and trope turning toward Turning to energy Motivation for a Second Law!! First law allows us to calculate the energy

More information

Chapter 12. The Laws of Thermodynamics. First Law of Thermodynamics

Chapter 12. The Laws of Thermodynamics. First Law of Thermodynamics Chapter 12 The Laws of Thermodynamics First Law of Thermodynamics The First Law of Thermodynamics tells us that the internal energy of a system can be increased by Adding energy to the system Doing work

More information

Chapter 20. Heat Engines, Entropy and the Second Law of Thermodynamics. Dr. Armen Kocharian

Chapter 20. Heat Engines, Entropy and the Second Law of Thermodynamics. Dr. Armen Kocharian Chapter 20 Heat Engines, Entropy and the Second Law of Thermodynamics Dr. Armen Kocharian First Law of Thermodynamics Review Review: The first law states that a change in internal energy in a system can

More information

Chap. 3 The Second Law. Spontaneous change

Chap. 3 The Second Law. Spontaneous change Chap. 3 The Second Law Spontaneous change Some things happen naturally; some things don t. the spontaneous direction of change, the direction of change that does not require work to be done to bring it

More information

AP PHYSICS 2 WHS-CH-15 Thermodynamics Show all your work, equations used, and box in your answers!

AP PHYSICS 2 WHS-CH-15 Thermodynamics Show all your work, equations used, and box in your answers! AP PHYSICS 2 WHS-CH-15 Thermodynamics Show all your work, equations used, and box in your answers! Nicolas Léonard Sadi Carnot (1796-1832) Sadi Carnot was a French military engineer and physicist, often

More information

Survey of Thermodynamic Processes and First and Second Laws

Survey of Thermodynamic Processes and First and Second Laws Survey of Thermodynamic Processes and First and Second Laws Please select only one of the five choices, (a)-(e) for each of the 33 questions. All temperatures T are absolute temperatures. All experiments

More information

Lecture 2 Entropy and Second Law

Lecture 2 Entropy and Second Law Lecture 2 Entropy and Second Law Etymology: Entropy, entropie in German. En from energy and trope turning toward Turning to energy Zeroth law temperature First law energy Second law - entropy CY1001 2010

More information

October 18, 2011 Carnot cycle - 1

October 18, 2011 Carnot cycle - 1 Carnot Cycle In 1824, Sadi Carnot (1796-1832) published a short book, eflections on the Motive Power of Fire (The book is now free online You should try it out) To construct an engine, Carnot noted, at

More information

Basic thermodynamics. heat to the high temperature reservoir.

Basic thermodynamics. heat to the high temperature reservoir. Consider a heat engine that is operating in a cyclic process takes heat (QH) from a high temperature reservoir & converts completely into work (W), violating the Kelvin Planck statement. Let the work W,

More information

Chap. 3. The Second Law. Law of Spontaneity, world gets more random

Chap. 3. The Second Law. Law of Spontaneity, world gets more random Chap. 3. The Second Law Law of Spontaneity, world gets more random Kelvin - No process can transform heat completely into work Chap. 3. The Second Law Law of Spontaneity, world gets more random Kelvin

More information

Chapter 16 Thermodynamics

Chapter 16 Thermodynamics Nicholas J. Giordano www.cengage.com/physics/giordano Chapter 16 Thermodynamics Thermodynamics Introduction Another area of physics is thermodynamics Continues with the principle of conservation of energy

More information

The Kelvin-Planck statement of the second law

The Kelvin-Planck statement of the second law The Kelvin-Planck statement of the second law It is impossible for any device that operates on a cycle to receive heat from a single reservoir and produce a net amount of work Q W E =ΔE net net net, mass

More information

Examples. Fire Piston (demo) Example (Comparison of processes)

Examples. Fire Piston (demo) Example (Comparison of processes) Examples Fire Piston (demo) Fire Piston istory http://en.wikipedia.org/wiki/fire_piston Example 19.68 (Comparison of processes) Fire piston calculations http://complex.gmu.edu/www-phys/phys262/soln/fire_piston.pdf

More information

SECOND LAW OF THERMODYNAMICS

SECOND LAW OF THERMODYNAMICS SECOND LAW OF THERMODYNAMICS 2 ND Law of Thermodynamics Puts a limitation on the conversion of some forms of energy Determines the scope of an energy conversion and if an energy conversion is possible

More information

The Story of Spontaneity and Energy Dispersal. You never get what you want: 100% return on investment

The Story of Spontaneity and Energy Dispersal. You never get what you want: 100% return on investment The Story of Spontaneity and Energy Dispersal You never get what you want: 100% return on investment Spontaneity Spontaneous process are those that occur naturally. Hot body cools A gas expands to fill

More information

CARNOT CYCLE = T = S ( U,V )

CARNOT CYCLE = T = S ( U,V ) hermodynamics CANO CYCE Do not trouble students with history In 1824, Sadi Carnot (1796-1832) published a short book, eflections on the Motive Power of Fire (he book is now free online You should try it

More information

18.13 Review & Summary

18.13 Review & Summary 5/2/10 10:04 PM Print this page 18.13 Review & Summary Temperature; Thermometers Temperature is an SI base quantity related to our sense of hot and cold. It is measured with a thermometer, which contains

More information

Irreversible Processes

Irreversible Processes Irreversible Processes Examples: Block sliding on table comes to rest due to friction: KE converted to heat. Heat flows from hot object to cold object. Air flows into an evacuated chamber. Reverse process

More information

Reversibility. Processes in nature are always irreversible: far from equilibrium

Reversibility. Processes in nature are always irreversible: far from equilibrium Reversibility Processes in nature are always irreversible: far from equilibrium Reversible process: idealized process infinitely close to thermodynamic equilibrium (quasi-equilibrium) Necessary conditions

More information

12 The Laws of Thermodynamics

12 The Laws of Thermodynamics June 14, 1998 12 The Laws of Thermodynamics Using Thermal Energy to do Work Understanding the laws of thermodynamics allows us to use thermal energy in a practical way. The first law of thermodynamics

More information

Chapter 16 The Second Law of Thermodynamics

Chapter 16 The Second Law of Thermodynamics Chapter 16 The Second Law of Thermodynamics To examine the directions of thermodynamic processes. To study heat engines. To understand internal combustion engines and refrigerators. To learn and apply

More information

UNIT 15: THERMODYNAMICS

UNIT 15: THERMODYNAMICS UNIT 15: THERMODYNAMICS ENTHALPY, DH ENTROPY, DS GIBBS FREE ENERGY, DG ENTHALPY, DH Energy Changes in Reactions Heat is the transfer of thermal energy between two bodies that are at different temperatures.

More information

Chapter 5. The Second Law of Thermodynamics (continued)

Chapter 5. The Second Law of Thermodynamics (continued) hapter 5 he Second Law of hermodynamics (continued) Second Law of hermodynamics Alternative statements of the second law, lausius Statement of the Second Law It is impossible for any system to operate

More information

MME 2010 METALLURGICAL THERMODYNAMICS II. Fundamentals of Thermodynamics for Systems of Constant Composition

MME 2010 METALLURGICAL THERMODYNAMICS II. Fundamentals of Thermodynamics for Systems of Constant Composition MME 2010 METALLURGICAL THERMODYNAMICS II Fundamentals of Thermodynamics for Systems of Constant Composition Thermodynamics addresses two types of problems: 1- Computation of energy difference between two

More information

T s change via collisions at boundary (not mechanical interaction)

T s change via collisions at boundary (not mechanical interaction) Lecture 14 Interaction of 2 systems at different temperatures Irreversible processes: 2nd Law of Thermodynamics Chapter 19: Heat Engines and Refrigerators Thermal interactions T s change via collisions

More information

SPONTANEOUS PROCESSES AND THERMODYNAMIC EQUILIBRIUM

SPONTANEOUS PROCESSES AND THERMODYNAMIC EQUILIBRIUM 13 CHAPER SPONANEOUS PROCESSES AND HERMODYNAMIC EQUILIBRIUM 13.1 he Nature of Spontaneous Processes 13.2 Entropy and Spontaneity: A Molecular Statistical Interpretation 13.3 Entropy and Heat: Macroscopic

More information

Gibbs Paradox Solution

Gibbs Paradox Solution Gibbs Paradox Solution James A. Putnam he Gibbs paradox results from analyzing mixing entropy as if it is a type of thermodynamic entropy. It begins with an adiabatic box divided in half by an adiabatic

More information

I.D The Second Law Q C

I.D The Second Law Q C I.D he Second Law he historical development of thermodynamics follows the industrial revolution in the 19 th century, and the advent of heat engines. It is interesting to see how such practical considerations

More information

The Direction of Spontaneous Change: Entropy and Free Energy

The Direction of Spontaneous Change: Entropy and Free Energy The Direction of Spontaneous Change: Entropy and Free Energy Reading: from Petrucci, Harwood and Herring (8th edition): Required for Part 1: Sections 20-1 through 20-4. Recommended for Part 1: Sections

More information

1. INTRODUCTION TO REFRIGERATION AND AIR CONDITION

1. INTRODUCTION TO REFRIGERATION AND AIR CONDITION CHAPTER ONE 1. INTRODUCTION TO REFRIGERATION AND AIR CONDITION Refrigeration may be defined as the process of reducing and maintaining a temperature of a space or material below that of the surroundings.

More information

Thermodynamic Systems, States, and Processes

Thermodynamic Systems, States, and Processes Thermodynamics Thermodynamic Systems, States, and Processes A thermodynamic system is described by an equation of state, such as the ideal gas law. The location of the state can be plotted on a p V diagram,

More information

SECOND LAW OF THERMODYNAMICS

SECOND LAW OF THERMODYNAMICS SECOND LAW OF THERMODYNAMICS 2 ND Law of Thermodynamics Puts a limitation on the conversion of some forms of energy Determines the scope of an energy conversion and if an energy conversion is possible

More information

Entropy, free energy and equilibrium. Spontaneity Entropy Free energy and equilibrium

Entropy, free energy and equilibrium. Spontaneity Entropy Free energy and equilibrium Entropy, free energy and equilibrium Spontaneity Entropy Free energy and equilibrium Learning objectives Discuss what is meant by spontaneity Discuss energy dispersal and its relevance to spontaneity Describe

More information

Chapter 19. Chemical Thermodynamics

Chapter 19. Chemical Thermodynamics Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 19 John D. Bookstaver St. Charles Community College Cottleville, MO First Law of You will

More information

Physics 207 Lecture 27. Lecture 26. Chapters 18, entropy and second law of thermodynamics Chapter 19, heat engines and refrigerators

Physics 207 Lecture 27. Lecture 26. Chapters 18, entropy and second law of thermodynamics Chapter 19, heat engines and refrigerators Goals: Lecture 26 Chapters 18, entropy and second law of thermodynamics Chapter 19, heat engines and refrigerators Reading assignment for Wednesday: Chapter 20. Physics 207: Lecture 27, Pg 1 Entropy A

More information

Thermodynamics II. Week 9

Thermodynamics II. Week 9 hermodynamics II Week 9 Example Oxygen gas in a piston cylinder at 300K, 00 kpa with volume o. m 3 is compressed in a reversible adiabatic process to a final temperature of 700K. Find the final pressure

More information

CHAPTER - 12 THERMODYNAMICS

CHAPTER - 12 THERMODYNAMICS CHAPER - HERMODYNAMICS ONE MARK QUESIONS. What is hermodynamics?. Mention the Macroscopic variables to specify the thermodynamics. 3. How does thermodynamics differ from Mechanics? 4. What is thermodynamic

More information

Physical Biochemistry. Kwan Hee Lee, Ph.D. Handong Global University

Physical Biochemistry. Kwan Hee Lee, Ph.D. Handong Global University Physical Biochemistry Kwan Hee Lee, Ph.D. Handong Global University Week 3 CHAPTER 2 The Second Law: Entropy of the Universe increases What is entropy Definition: measure of disorder The greater the disorder,

More information

Chemical thermodynamics the area of chemistry that deals with energy relationships

Chemical thermodynamics the area of chemistry that deals with energy relationships Chemistry: The Central Science Chapter 19: Chemical Thermodynamics Chemical thermodynamics the area of chemistry that deals with energy relationships 19.1: Spontaneous Processes First law of thermodynamics

More information

Test Exchange Thermodynamics (C) Test Answer Key

Test Exchange Thermodynamics (C) Test Answer Key 1 Test Exchange Thermodynamics (C) Test Answer Key Made by Montgomery High School montyscioly@gmail.com 2 Questions are worth between 1 to 3 points. Show calculations for all open-ended math questions

More information

Test Exchange Thermodynamics (C) Test Team Name: Team Number: Score: / 43. Made by Montgomery High School -

Test Exchange Thermodynamics (C) Test Team Name: Team Number: Score: / 43. Made by Montgomery High School - 1 Test Exchange Thermodynamics (C) Test Team Name: Team Number: Score: / 43 Made by Montgomery High School - montyscioly@gmail.com 2 Questions are worth between 1 and 3 points. Show calculations for all

More information

Engineering Thermodynamics. Chapter 5. The Second Law of Thermodynamics

Engineering Thermodynamics. Chapter 5. The Second Law of Thermodynamics 5.1 Introduction Chapter 5 The Second aw of Thermodynamics The second law of thermodynamics states that processes occur in a certain direction, not in just any direction. Physical processes in nature can

More information

Reversible Processes. Furthermore, there must be no friction (i.e. mechanical energy loss) or turbulence i.e. it must be infinitely slow.

Reversible Processes. Furthermore, there must be no friction (i.e. mechanical energy loss) or turbulence i.e. it must be infinitely slow. Reversible Processes A reversible thermodynamic process is one in which the universe (i.e. the system and its surroundings) can be returned to their initial conditions. Because heat only flows spontaneously

More information

Second Law of Thermodynamics -

Second Law of Thermodynamics - Second Law of Thermodynamics - REVIEW ENTROPY EXAMPLE Dr. Garrick 1/19/09 First Law of Thermodynamics you can t win! First Law of Thermodynamics: Energy cannot be Created or Destroyed the total energy

More information

Distinguish between an isothermal process and an adiabatic process as applied to an ideal gas (2)

Distinguish between an isothermal process and an adiabatic process as applied to an ideal gas (2) 1. This question is about thermodynamic processes. (a) Distinguish between an isothermal process and an adiabatic process as applied to an ideal gas.......... An ideal gas is held in a container by a moveable

More information

The Second Law of Thermodynamics

The Second Law of Thermodynamics he Second Law of hermodynamics So far We have studied the second law by looking at its results We don t have a thermodynamic property that can describe it In this chapter we will develop a mathematical

More information

Heat Machines (Chapters 18.6, 19)

Heat Machines (Chapters 18.6, 19) eat Machines (hapters 8.6, 9) eat machines eat engines eat pumps The Second Law of thermodynamics Entropy Ideal heat engines arnot cycle Other cycles: Brayton, Otto, Diesel eat Machines Description The

More information

Lecture Outline Chapter 18. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc.

Lecture Outline Chapter 18. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc. Lecture Outline Chapter 18 Physics, 4 th Edition James S. Walker Chapter 18 The Laws of Thermodynamics Units of Chapter 18 The Zeroth Law of Thermodynamics The First Law of Thermodynamics Thermal Processes

More information

Second Law of Thermodynamics

Second Law of Thermodynamics Dr. Alain Brizard College Physics II (PY 211) Second Law of Thermodynamics Textbook Reference: Chapter 20 sections 1-4. Second Law of Thermodynamics (Clausius) Heat flows naturally from a hot object to

More information

Thermodynamics. 1.1 Introduction. Thermodynamics is a phenomenological description of properties of macroscopic systems in thermal equilibrium.

Thermodynamics. 1.1 Introduction. Thermodynamics is a phenomenological description of properties of macroscopic systems in thermal equilibrium. 1 hermodynamics 1.1 Introduction hermodynamics is a phenomenological description of properties of macroscopic systems in thermal equilibrium. Imagine yourself as a post-newtonian physicist intent on understanding

More information

5/6/ :41 PM. Chapter 6. Using Entropy. Dr. Mohammad Abuhaiba, PE

5/6/ :41 PM. Chapter 6. Using Entropy. Dr. Mohammad Abuhaiba, PE Chapter 6 Using Entropy 1 2 Chapter Objective Means are introduced for analyzing systems from the 2 nd law perspective as they undergo processes that are not necessarily cycles. Objective: introduce entropy

More information

Thermodynamic Third class Dr. Arkan J. Hadi

Thermodynamic Third class Dr. Arkan J. Hadi 5.5 ENTROPY CHANGES OF AN IDEAL GAS For one mole or a unit mass of fluid undergoing a mechanically reversible process in a closed system, the first law, Eq. (2.8), becomes: Differentiation of the defining

More information

Chapter 19. Heat Engines

Chapter 19. Heat Engines Chapter 19 Heat Engines Thermo Processes Eint = Q+ W Adiabatic No heat exchanged Q = 0 and E int = W Isobaric Constant pressure W = P (V f V i ) and E int = Q + W Isochoric Constant Volume W = 0 and E

More information

Chapter 20 Entropy and the 2nd Law of Thermodynamics

Chapter 20 Entropy and the 2nd Law of Thermodynamics Chapter 20 Entropy and the 2nd Law of Thermodynamics A one-way processes are processes that can occur only in a certain sequence and never in the reverse sequence, like time. these one-way processes are

More information

Chapter 19. Chemical Thermodynamics

Chapter 19. Chemical Thermodynamics Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 19 John D. Bookstaver St. Charles Community College Cottleville, MO First Law of You will

More information

Spring_#8. Thermodynamics. Youngsuk Nam

Spring_#8. Thermodynamics. Youngsuk Nam Spring_#8 Thermodynamics Youngsuk Nam ysnam1@khu.ac.krac kr Ch.7: Entropy Apply the second law of thermodynamics to processes. Define a new property called entropy to quantify the secondlaw effects. Establish

More information

Minimum Bias Events at ATLAS

Minimum Bias Events at ATLAS Camille Bélanger-Champagne McGill University Lehman College City University of New York Thermodynamics Charged Particle and Statistical Correlations Mechanics in Minimum Bias Events at ATLAS Thermodynamics

More information

Two mark questions and answers UNIT II SECOND LAW 1. Define Clausius statement. It is impossible for a self-acting machine working in a cyclic process, to transfer heat from a body at lower temperature

More information

Addison Ault, Department of Chemistry, Cornell College, Mt. Vernon IA. The Carnot cycle is usually described in terms of classical

Addison Ault, Department of Chemistry, Cornell College, Mt. Vernon IA. The Carnot cycle is usually described in terms of classical 1 The Carnot Cycle: from Classical Thermo to Stat Thermo Addison Ault, Department of Chemistry, Cornell College, Mt. Vernon IA The Carnot cycle is usually described in terms of classical thermodynamics,

More information

Free expansion (Joule); Constant U Forced expansion (Joule-Kelvin); Constant H. Joule-Kelvin coefficient - heating or cooling on JK expansion?

Free expansion (Joule); Constant U Forced expansion (Joule-Kelvin); Constant H. Joule-Kelvin coefficient - heating or cooling on JK expansion? ...Thermodynamics Adiabats: How c P and c V get into the exponent PV γ Free expansion (Joule); Constant U Forced expansion (Joule-Kelvin); Constant H Joule-Kelvin coefficient - heating or cooling on JK

More information

Chapter 12 Thermodynamics

Chapter 12 Thermodynamics Chapter 12 Thermodynamics 12.1 Thermodynamic Systems, States, and Processes System: definite quantity of matter with real or imaginary boundaries If heat transfer is impossible, the system is thermally

More information

Chapter 19 Chemical Thermodynamics

Chapter 19 Chemical Thermodynamics Chapter 19 Chemical Thermodynamics Spontaneous Processes Entropy and the Second Law of Thermodynamics The Molecular Interpretation of Entropy Entropy Changes in Chemical Reactions Gibbs Free Energy Free

More information

Adiabatic Expansion (DQ = 0)

Adiabatic Expansion (DQ = 0) Adiabatic Expansion (DQ = 0) Occurs if: change is made sufficiently quickly and/or with good thermal isolation. Governing formula: PV g = constant where g = C P /C V Adiabat P Isotherms V Because PV/T

More information

More Thermodynamics. Specific Specific Heats of a Gas Equipartition of Energy Reversible and Irreversible Processes

More Thermodynamics. Specific Specific Heats of a Gas Equipartition of Energy Reversible and Irreversible Processes More Thermodynamics Specific Specific Heats of a Gas Equipartition of Energy Reversible and Irreversible Processes Carnot Cycle Efficiency of Engines Entropy More Thermodynamics 1 Specific Heat of Gases

More information

Classification following properties of the system in Intensive and Extensive

Classification following properties of the system in Intensive and Extensive Unit I Classification following properties of the system in Intensive and Extensive Extensive : mass, weight, volume, potential energy, Kinetic energy, Internal energy, entropy, exergy, energy, magnetization

More information

Chapter 20 The Second Law of Thermodynamics

Chapter 20 The Second Law of Thermodynamics Chapter 20 The Second Law of Thermodynamics When we previously studied the first law of thermodynamics, we observed how conservation of energy provided us with a relationship between U, Q, and W, namely

More information

Entropy and the second law of thermodynamics

Entropy and the second law of thermodynamics Chapter 4 Entropy and the second law of thermodynamics 4.1 Heat engines In a cyclic transformation the final state of a system is by definition identical to the initial state. he overall change of the

More information

Content. Entropy and principle of increasing entropy. Change of entropy in an ideal gas.

Content. Entropy and principle of increasing entropy. Change of entropy in an ideal gas. Entropy Content Entropy and principle of increasing entropy. Change of entropy in an ideal gas. Entropy Entropy can be viewed as a measure of molecular disorder, or molecular randomness. As a system becomes

More information

Chem Lecture Notes 6 Fall 2013 Second law

Chem Lecture Notes 6 Fall 2013 Second law Chem 340 - Lecture Notes 6 Fall 2013 Second law In the first law, we determined energies, enthalpies heat and work for any process from an initial to final state. We could know if the system did work or

More information

Chapter Notes Subject: Chemistry Class: XI Chapter: Thermodynamics Top concepts

Chapter Notes Subject: Chemistry Class: XI Chapter: Thermodynamics Top concepts Chapter Notes Subject: Chemistry Class: XI Chapter: Thermodynamics Top concepts 1. The branch of science which deals with study of different forms of energy and their interconversion is called thermodynamics.

More information

CHAPTER 3 LECTURE NOTES 3.1. The Carnot Cycle Consider the following reversible cyclic process involving one mole of an ideal gas:

CHAPTER 3 LECTURE NOTES 3.1. The Carnot Cycle Consider the following reversible cyclic process involving one mole of an ideal gas: CHATER 3 LECTURE NOTES 3.1. The Carnot Cycle Consider the following reversible cyclic process involving one mole of an ideal gas: Fig. 3. (a) Isothermal expansion from ( 1, 1,T h ) to (,,T h ), (b) Adiabatic

More information

Chapter 19. Chemical Thermodynamics

Chapter 19. Chemical Thermodynamics Chapter 19. Chemical Thermodynamics 19.1 Spontaneous Processes Chemical thermodynamics is concerned with energy relationships in chemical reactions. We consider enthalpy and we also consider entropy in

More information

Introduction to Aerospace Propulsion. Prof. Bhaskar Roy. Prof. A. M. Pradeep. Department of Aerospace Engineering

Introduction to Aerospace Propulsion. Prof. Bhaskar Roy. Prof. A. M. Pradeep. Department of Aerospace Engineering Introduction to Aerospace Propulsion Prof. Bhaskar Roy Prof. A. M. Pradeep Department of Aerospace Engineering Indian Institute of Technology, Bombay Module No. # 01 Lecture No. # 11 Reversible and irreversible

More information

Lecture 29-30: Closed system entropy balance

Lecture 29-30: Closed system entropy balance ME 200 Thermodynamics I Spring 2016 Lecture 29-30: Closed system entropy balance Yong Li Shanghai Jiao Tong University Institute of Refrigeration and Cryogenics 800 Dong Chuan Road Shanghai, 200240, P.

More information

Thermodynamic system is classified into the following three systems. (ii) Closed System It exchanges only energy (not matter) with surroundings.

Thermodynamic system is classified into the following three systems. (ii) Closed System It exchanges only energy (not matter) with surroundings. 1 P a g e The branch of physics which deals with the study of transformation of heat energy into other forms of energy and vice-versa. A thermodynamical system is said to be in thermal equilibrium when

More information

University Physics (Prof. David Flory) Chapt_21 Monday, November 26, 2007 Page 1

University Physics (Prof. David Flory) Chapt_21 Monday, November 26, 2007 Page 1 University Physics (Prof. David Flory) Chapt_21 Monday, November 26, 2007 Page 1 Name: Date: 1. Let k be the Boltzmann constant. If the configuration of the molecules in a gas changes so that the multiplicity

More information

Downloaded from

Downloaded from Chapter 12 (Thermodynamics) Multiple Choice Questions Single Correct Answer Type Q1. An ideal gas undergoes four different processes from the same initial state (figure). Four processes are adiabatic,

More information

1. Second Law of Thermodynamics

1. Second Law of Thermodynamics 1. Second Law of hermodynamics he first law describes how the state of a system changes in response to work it performs and heat absorbed. he second law deals with direction of thermodynamic processes

More information

1. Second Law of Thermodynamics

1. Second Law of Thermodynamics 1. Second Law of hermodynamics he first law describes how the state of a system changes in response to work it performs and heat absorbed. However, the first law cannot explain certain facts about thermal

More information

THERMODYNAMICS. Topic: 4 Spontaneous processes and criteria for spontaneity, entropy as a state function. VERY SHORT ANSWER QUESTIONS

THERMODYNAMICS. Topic: 4 Spontaneous processes and criteria for spontaneity, entropy as a state function. VERY SHORT ANSWER QUESTIONS THERMODYNAMICS Topic: 4 Spontaneous processes and criteria for spontaneity, entropy as a state function. VERY SHORT ANSWER QUESTIONS 1. State Hess s law? Ans. Hess s law: The total heat change in a reaction

More information

Chapter 19 Chemical Thermodynamics

Chapter 19 Chemical Thermodynamics Chapter 19 Chemical Thermodynamics Kinetics How fast a rxn. proceeds Equilibrium How far a rxn proceeds towards completion Thermodynamics Study of energy relationships & changes which occur during chemical

More information

THERMODYNAMICS. Zeroth law of thermodynamics. Isotherm

THERMODYNAMICS. Zeroth law of thermodynamics. Isotherm 12 THERMODYNAMICS Zeroth law of thermodynamics Two systems separately in thermal equilibrium with a third system are in thermal equilibrium with each other. Isotherm It is the graph connecting pressure

More information

Thermodynamics: Reversibility and Carnot

Thermodynamics: Reversibility and Carnot Thermodynamics: Reversibility and Carnot From Warmup It seems like this reading (for Friday) explained the homework assigned for Wednesday's lecture. Is homework based on the previous lecture, or the current

More information

The Second Law of Thermodynamics

The Second Law of Thermodynamics CHEM 331 Physical Chemistry Fall 2017 The Second Law of Thermodynamics We have now reached a major milestone for the course; and are ready to enunciate the Second Law of Thermodynamics. The 0 th and 1

More information

CHAPTER 7 ENTROPY. Copyright Hany A. Al-Ansary and S. I. Abdel-Khalik (2014) 1

CHAPTER 7 ENTROPY. Copyright Hany A. Al-Ansary and S. I. Abdel-Khalik (2014) 1 CHAPTER 7 ENTROPY S. I. Abdel-Khalik (2014) 1 ENTROPY The Clausius Inequality The Clausius inequality states that for for all cycles, reversible or irreversible, engines or refrigerators: For internally-reversible

More information

Lecture 26. Second law of thermodynamics. Heat engines and refrigerators.

Lecture 26. Second law of thermodynamics. Heat engines and refrigerators. ecture 26 Second law of thermodynamics. Heat engines and refrigerators. The Second aw of Thermodynamics Introduction The absence of the process illustrated above indicates that conservation of energy is

More information

Laws of Thermodynamics

Laws of Thermodynamics Laws of Thermodynamics The Three Laws of Thermodynamics - The first lawof thermodynamics, also called conservation of energy. We can use this knowledge to determine the amount of energy in a system, the

More information

Chapter 19. Heat Engines

Chapter 19. Heat Engines Chapter 19 Heat Engines QuickCheck 19.11 The efficiency of this Carnot heat engine is A. Less than 0.5. B. 0.5. C. Between 0.5 and 1.0. D. 2.0. E. Can t say without knowing Q H. 2013 Pearson Education,

More information

T H E R M O D Y N A M I C S M E

T H E R M O D Y N A M I C S M E T H E R M O D Y N A M I C S M E THERMODYNAMICS CONTENTS 1 BASIC CONCEPTS IN THERMODYNAMICS 2 TEMPERATURE 3 WORK AND HEAT TRANSFER Thermodynamic system, surroundings, universe, system boundary Types of

More information

UNIVERSITY COLLEGE LONDON. University of London EXAMINATION FOR INTERNAL STUDENTS. For The Following Qualifications:-

UNIVERSITY COLLEGE LONDON. University of London EXAMINATION FOR INTERNAL STUDENTS. For The Following Qualifications:- UNIVERSITY COLLEGE LONDON University of London EXAMINATION FOR INTERNAL STUDENTS For The Following Qualifications:- B.Sc. M.Sci. Physics 1B28: Thermal Physics COURSE CODE : PHYSIB28 UNIT VALUE : 0.50 DATE

More information

Temperature Thermal Expansion Ideal Gas Law Kinetic Theory Heat Heat Transfer Phase Changes Specific Heat Calorimetry Heat Engines

Temperature Thermal Expansion Ideal Gas Law Kinetic Theory Heat Heat Transfer Phase Changes Specific Heat Calorimetry Heat Engines Temperature Thermal Expansion Ideal Gas Law Kinetic Theory Heat Heat Transfer Phase Changes Specific Heat Calorimetry Heat Engines Zeroeth Law Two systems individually in thermal equilibrium with a third

More information

THE SECOND LAW OF THERMODYNAMICS. Professor Benjamin G. Levine CEM 182H Lecture 5

THE SECOND LAW OF THERMODYNAMICS. Professor Benjamin G. Levine CEM 182H Lecture 5 THE SECOND LAW OF THERMODYNAMICS Professor Benjamin G. Levine CEM 182H Lecture 5 Chemical Equilibrium N 2 + 3 H 2 2 NH 3 Chemical reactions go in both directions Systems started from any initial state

More information

First Law showed the equivalence of work and heat. Suggests engine can run in a cycle and convert heat into useful work.

First Law showed the equivalence of work and heat. Suggests engine can run in a cycle and convert heat into useful work. 0.0J /.77J / 5.60J hermodynamics of Biomolecular Systems 0.0/5.60 Fall 005 Lecture #6 page he Second Law First Law showed the euivalence of work and heat U = + w, du = 0 for cyclic process = w Suggests

More information

Department of Mechanical Engineering ME 322 Mechanical Engineering Thermodynamics. Introduction to 2 nd Law and Entropy.

Department of Mechanical Engineering ME 322 Mechanical Engineering Thermodynamics. Introduction to 2 nd Law and Entropy. Department of Mechanical Engineering ME 322 Mechanical Engineering hermodynamics Introduction to 2 nd aw and Entropy ecture 18 Example Consider an adiabatic compressor steadily moving R125, P2 2 430 psia

More information

Thermodynamics: An Engineering Approach Seventh Edition Yunus A. Cengel, Michael A. Boles McGraw-Hill, Chapter 7 ENTROPY

Thermodynamics: An Engineering Approach Seventh Edition Yunus A. Cengel, Michael A. Boles McGraw-Hill, Chapter 7 ENTROPY Thermodynamics: An Engineering Approach Seventh Edition Yunus A. Cengel, Michael A. Boles McGraw-Hill, 2011 Chapter 7 ENTROPY Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction

More information

Chapter 1: FUNDAMENTAL CONCEPTS OF THERMODYNAMICS AND VARIOUS THERMODYMIC PROCESSES

Chapter 1: FUNDAMENTAL CONCEPTS OF THERMODYNAMICS AND VARIOUS THERMODYMIC PROCESSES Chapter 1: FUNDAMENTAL CONCEPTS OF THERMODYNAMICS AND VARIOUS THERMODYMIC PROCESSES Thermodynamics is that branch of science which deals with energy transfer A system may be closed, open or isolated system

More information