Phu Xuan University Library
Thermodynamics and Chemical Equilibrium

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Thermodynamics and Chemical Equilibrium

Physical chemistry encompasses a wide variety of ideas that are intimately linked. For the most part, we cannot understand one without having some understanding of many others. We overcome this problem by looking at the same idea from a series of slightly different and increasingly sophisticated perspectives. This book focuses on the theories of physical chemistry that describe and make predictions about chemical equilibrium.

Author
Paul Ellgen
Publisher
Oklahoma School of Science Mathematics
Source
LibreTexts
License
CC BY-SA
Language
EN
Category
Basic Sciences
Contents· 362 sections
  1. 01: Introduction - Background and a Look Ahead
  2. 1.01: The Role of the Ideal Gas
  3. 1.02: Chemical Kinetics
  4. 1.03: Classical Thermodynamics
  5. 1.04: Statistical Thermodynamics
  6. 1.05: Heat Transfer in Practical Devices
  7. 1.06: The Concept of Equilibrium
  8. 1.07: Chemical Equilibrium and Predicting Chemical Change
  9. 1.08: Equilibrium and Classical Thermodynamics
  10. 1.09: A Few Ideas from the Philosophy of Science
  11. 1.10: A Few Ideas from Formal Logic
  12. 1.11: Problems
  13. 02: Gas Laws
  14. 2.01: Boyle's Law
  15. 2.02: Charles' Law
  16. 2.03: Avogadro's Hypothesis
  17. 2.04: Finding Avogadro's Number
  18. 2.05: The Kelvin Temperature Scale
  19. 2.06: Deriving the Ideal Gas Law from Boyle's and Charles' Laws
  20. 2.07: The Ideal Gas Constant and Boltzmann's Constant
  21. 2.08: Real Gases Versus Ideal Gases
  22. 2.09: Temperature and the Ideal Gas Thermometer
  23. 2.10: Deriving Boyle's Law from Newtonian Mechanics
  24. 2.11: The Barometric Formula
  25. 2.12: Van der Waals' Equation
  26. 2.13: Virial Equations
  27. 2.14: Gas Mixtures - Dalton's Law of Partial Pressures
  28. 2.15: Gas Mixtures - Amagat's Law of Partial Volums
  29. 2.16: Problems
  30. 03: Distributions Probability and Expected Values
  31. 3.01: The Distribution Function as a Summary of Experimental Results
  32. 3.02: Outcomes Events and Probability
  33. 3.03: Some Important Properties of Events
  34. 3.04: Applying the Laws of Probability
  35. 3.05: Bar Graphs and Histograms
  36. 3.06: Continuous Distribution Functions - the Envelope Function is the Derivative of the Area
  37. 3.07: A Heuristic View of the Probability Density Function
  38. 3.08: A Heuristic View of the Cumulative Distribution Function
  39. 3.09: Random Variables Expected Values and Population Sets
  40. 3.10: Statistics - the Mean and the Variance of a Distribution
  41. 3.11: The Variance of the Average- The Central Limit Theorem
  42. 3.12: The Normal Distribution
  43. 3.13: The Expected Value of a Function of Several Variables and the Central Limit Theorem
  44. 3.14: Where Does the N - 1 Come from
  45. 3.15: Problems
  46. 04: The Distribution of Gas Velocities
  47. 4.01: Distribution Functions for Gas-velocity Components
  48. 4.02: Probability Density Functions for Velocity Components in Spherical Coordinates
  49. 4.03: Maxwell's Derivation of the Gas-velocity Probability-density Function
  50. 4.04: The Probability-density Function for Gas Velocities in One Dimension
  51. 4.05: Combining the One-dimensional Probability Density Functions
  52. 4.06: Boyle's Law from the Maxwell-Boltzmann Probability Density
  53. 4.07: Experimental Test of the Maxwell-Boltzmann Probability Density
  54. 4.08: Statistics for Molecular Speeds
  55. 4.09: Pressure Variations for Macroscopic Samples
  56. 4.10: Collisions between Gas Molecules Relative Velocity Coordinates
  57. 4.11: The Probability Density Function for the Relative Velocity
  58. 4.12: The Frequency of Collisions between Unlike Gas Molecules
  59. 4.13: The Rate of Collisions between Unlike Gas Molecules
  60. 4.14: Collisions between like Gas Molecules
  61. 4.15: The Geometry of A Collision between Spherical Molecules
  62. 4.16: The Energy of A Collision between Gas Molecules
  63. 4.17: Problems
  64. 05: Chemical Kinetics Reaction Mechanisms and Chemical Equilibrium
  65. 5.01: Chemical Kinetics
  66. 5.02: Reaction Rates and Rate Laws
  67. 5.03: Simultaneous Processes
  68. 5.04: The Effect of Temperature on Reaction Rates
  69. 5.05: Other Factors that Affect Reaction Rates
  70. 5.06: Mechanisms and Elementary Processes
  71. 5.07: Rate Laws for Elementary Processes
  72. 5.08: Experimental Determination of Rate Laws
  73. 5.09: First-order Rate Processes
  74. 5.10: Rate Laws by the Study of Initial Rates
  75. 5.11: Rate Laws from Experiments in a Continuous Stirred Tank Reactor
  76. 5.12: Predicting Rate Laws from Proposed Mechanisms
  77. 5.13: The Michaelis-Menten Mechanism for Enzyme-catalyzed Reactions
  78. 5.14: The Lindemann-Hinshelwood Mechanism for First-order Decay
  79. 5.15: Why Unimolecular Reactions are First Order
  80. 5.16: The Mechanism of the Base Hydrolysis of Co(NH)X
  81. 5.17: Chemical Equilibrium as the Equality of Rates for Opposing Reactions
  82. 5.18: The Principle of Microscopic Reversibility
  83. 5.19: Microscopic Reversibility and the Second Law
  84. 5.20: Problems
  85. 06: Equilibrium States and Reversible Processes
  86. 6.01: The Thermodynamic Perspective
  87. 6.02: Thermodynamic Systems and Variables
  88. 6.03: Equilibrium and Reversibility - Phase Equilibria
  89. 6.04: Distribution Equilibria
  90. 6.05: Equilibria in Chemical Reactions
  91. 6.06: Le Chatelier's Principle
  92. 6.07: The Number of Variables Required to Specify Some Familiar Systems
  93. 6.08: Gibbs' Phase Rule
  94. 6.09: Reversible vs. Irreversible Processes
  95. 6.10: Duhem's Theorem - Specifying Reversible Change in A Closed System
  96. 6.11: Reversible Motion of A Mass in A Constant Gravitational Field
  97. 6.12: Equilibria and Reversible Processes
  98. 6.13: The Laws of Thermodynamics
  99. 6.14: Thermodynamic Criteria for Change
  100. 6.15: State Functions in Systems Undergoing Spontaneous Change
  101. 6.16: Problems
  102. 07: State Functions and The First Law
  103. 7.01: Changes in a State Function are Independent of Path
  104. 7.02: The Total Differential
  105. 7.03: Line Integrals
  106. 7.04: Exact Differentials and State Functions
  107. 7.05: Determining Whether an Expression is an Exact Differential
  108. 7.06: The Chain Rule and the Divide-through Rule
  109. 7.07: Measuring Pressure-Volume Work
  110. 7.08: Measuring Work- Non-Pressure-Volume Work
  111. 7.09: Measuring Heat
  112. 7.10: The First Law of Thermodynamics
  113. 7.11: Other Statements of the First Law
  114. 7.12: Notation for Changes in Thermodynamic Quantities - E vs. E
  115. 7.13: Heat Capacities for Gases- Cv Cp
  116. 7.14: Heat Capacities of Solids- the Law of Dulong and Petit
  117. 7.15: Defining Enthalpy H
  118. 7.16: Heat Transfer in Reversible Processes
  119. 7.17: Free Expansion of a Gas
  120. 7.18: Reversible vs. Irreversible Pressure-Volume Work
  121. 7.19: Isothermal Expansions of An Ideal Gas
  122. 7.20: Adiabatic Expansions of An Ideal Gas
  123. 7.21: Problems
  124. 08: Enthalpy and Thermochemical Cycles
  125. 8.01: Enthalpy
  126. 8.02: Using Thermochemical Cycles to Find Enthalpy Changes
  127. 8.03: How Enthalpy Depends on Pressure
  128. 8.04: Standard States and Enthalpies of Formation
  129. 8.05: The Ideal Gas Standard State
  130. 8.06: Standard Enthalpies of Reaction
  131. 8.07: Standard State Heat Capacities
  132. 8.08: How The Enthalpy Change for a Reaction Depends on Temperature
  133. 8.09: Calorimetry
  134. 8.10: Problems
  135. 09: The Second Law - Entropy and Spontaneous Change
  136. 9.01: The Second Law of Thermodynamics
  137. 9.02: The Carnot Cycle for an Ideal Gas and the Entropy Concept
  138. 9.03: The Carnot Cycle for Any Reversible System
  139. 9.04: The Entropy Change around Any Cycle for Any Reversible System
  140. 9.05: The Tiling Theorem and the Paths of Cyclic Process in Other Spaces
  141. 9.06: Entropy Changes for A Reversible Process
  142. 9.07: Entropy Changes for A Spontaneous Process in An Isolated System
  143. 9.08: The Entropy of the Universe
  144. 9.09: The Significance of The Machine-based Statement of The Second Law
  145. 9.10: A Slightly Philosophical Digression on Energy and Entropy
  146. 9.11: A Third Statement of the Second Law
  147. 9.12: Entropy and Predicting Change
  148. 9.13: Defining the Helmholtz and Gibbs Free Energies
  149. 9.14: The Fundamental Equation and Other Criteria for Reversible Change
  150. 9.15: Entropy and Spontaneous Change
  151. 9.16: Internal Entropy and the Second Law
  152. 9.17: Notation and Terminology- Conventions for Spontaneous Processes
  153. 9.18: The Heat Exchanged by A Spontaneous Process at Constant Entropy
  154. 9.19: The Energy Change for A Spontaneous Process at Constant S and V
  155. 9.20: The Enthalpy Change for A Spontaneous Process at Constant S and P
  156. 9.21: The Entropy Change for A Spontaneous Process at Constant E and V
  157. 9.22: The Entropy Change for A Spontaneous Process at Constant H and P
  158. 9.23: The Reversible Work is the Minimum Work at Constant T
  159. 9.24: The Free Energy Changes for A Spontaneous Process at Constant T
  160. 9.25: Summary- Thermodynamic Functions as Criteria for Change
  161. 9.26: Problems
  162. 10: Some Mathematical Consequences of the Fundamental Equation
  163. 10.01: Thermodynamic Relationships from dE dH dA and dG
  164. 10.02: dE TdS - PdV and Internal consistency
  165. 10.03: Expressing Thermodynamic Functions with Other Independent Variables
  166. 10.04: Expressing Thermodynamic Functions with Independent Variables V and T
  167. 10.05: Expressing Thermodynamic Functions with Independent Variables P and T
  168. 10.06: The Transformation of Thermodynamic Variables in General
  169. 10.07: Reversibility and Thermodynamic Variables in Gerneral
  170. 10.08: Using the Pair (V P) or the Pair (T S) as Independent Variables
  171. 10.09: The Relationship Between Cv and Cp for Any Substance
  172. 10.10: The Dependence of Cv on Volume and of Cp on Pressure
  173. 10.11: The Gibbs-Helmholtz Equation
  174. 10.12: The Second Law and the Properties of Ideal Gases
  175. 10.13: The second-dependence of the Energy and Enthalpy of A Real Gas
  176. 10.14: The Joule-Thomson Effect
  177. 10.15: Problems
  178. 11: The Third Law Absolute Entropy and the Gibbs Free Energy of Formation
  179. 11.01: Heat Capacity as a Function of Temperature
  180. 11.02: Enthalpy as a function of Temperature
  181. 11.03: The Third Law
  182. 11.04: Genesis of the Third Law - the Nernst Heat Theorem
  183. 11.05: Absolute Entropy
  184. 11.06: The Standard State for Third-law Entropies
  185. 11.07: The Fugacity of a Gas
  186. 11.08: A General Strategy for Expressing the Thermodynamic Properties of a Substance
  187. 11.09: The Standard Entropy and the Gibbs Free Energy of Formation
  188. 11.10: The Nature of Hypothetical States
  189. 11.11: The Fugacity and Gibbs Free Energy of A Substance in Any System
  190. 11.12: Evaluating Entropy Changes Using Thermochemical Cycles
  191. 11.13: Absolute Zero is Unattainable
  192. 11.14: Problems
  193. 12: Applications of the Thermodynamic Criteria for Change
  194. 12.01: Mechanical Processes
  195. 12.02: The Direction of Spontaneous Heat Transfer
  196. 12.03: Phase Changes - the Fusion of Ice
  197. 12.04: Measuring the Entropy Change for Any Reversible Process
  198. 12.05: Another Perspective on the Principle of Le Chatelier
  199. 12.06: Phase Equilibria - Temperature Dependence of the Boiling Point
  200. 12.07: Phase Equilibria - Temperature Dependence of the Melting Point
  201. 12.08: The Clapeyron Equation
  202. 12.09: The Clausius-Clapeyron Equation
  203. 12.10: Problems
  204. 13: Equilibria in Reactions of Ideal Gases
  205. 13.01: The Gibbs Free Energy of an Ideal Gas
  206. 13.02: The Gibbs Free Energy Change for A Reaction of Ideal Gases
  207. 13.03: The Thermodynamics of Mixing Ideal Gases
  208. 13.04: The Gibbs Free Energy Change for Reaction at Constant Partial Pressures
  209. 13.05: rG is the rate at which the Gibbs Free Energy Changes with The Extent of Reaction
  210. 13.06: The Standard Gibbs Free Energy Change and Equilibrium in Ideal Gas Reactions
  211. 13.07: The Gibbs Free Energy of Formation and Equilibrium in Ideal Gas Reactions
  212. 13.08: Equilibrium When A Component is Also Present as A Condensed Phase
  213. 13.09: Equilibrium When An Ideal Gas Component is Also Present as A solute
  214. 13.10: Problems
  215. 14: Chemical Potential - Extending the Scope of the Fundamental Equation
  216. 14.01: Dependence of the Internal Energy on the Composition of the System
  217. 14.02: Dependence of Other Thermodynamic Functions on the Composition
  218. 14.03: Partial Molar Quantities
  219. 14.04: Chemical Potentials and Stoichiometry
  220. 14.05: jdnj 0 and Primitive Vs. Gibbsian Equilibrium
  221. 14.06: The Change Criteria in A System Composed of Subsystems
  222. 14.07: At Constant P and T r is the Change in Gibbs Free Energy
  223. 14.08: Gibbs-Duhem Equation
  224. 14.09: The Dependence of Chemical Potential on Other Variables
  225. 14.10: Chemical Activity
  226. 14.11: Back to the Fugacity- the Fugacity of A Component of A Gas Mixture
  227. 14.12: Relating Fugacity and Chemical Activity
  228. 14.13: Relating the Differentials of Chemical Potential and Activity
  229. 14.14: Dependence of Activity on Temperature- Relative Partial Molar Enthalpies
  230. 14.15: Problems
  231. 15: Chemical Potential Fugacity Activity and Equilibrium
  232. 15.01: The Chemical Potential and Fugacity of a Gas
  233. 15.02: The Chemical Potential and Activity of a Gas
  234. 15.03: The Pressure-dependence of the Fugacity and Activity of a Condensed Phase
  235. 15.04: Standard States for the Fugacity and Activity of a Pure Solid
  236. 15.05: The Chemical Potential Fugacity and Activity of a Pure Solid
  237. 15.06: Chemical Potential Fugacity and Equilibrium
  238. 15.07: Chemical Potential Activity and Equilibrium
  239. 15.08: The Rate of Gibbs Free Energy Change with Extent of Reaction
  240. 15.09: Problems
  241. 16: The Chemical Activity of the Components of a Solution
  242. 16.01: Solutions Whose Components are in Equilibrium with Their Own Gases
  243. 16.02: Raoult's Law and Ideal Solutions
  244. 16.03: Expressing the Activity Coefficient as a Deviation from Raoult's Law
  245. 16.04: Henry's Law and the Fugacity and Activity of A Solution Component
  246. 16.05: Expressing the Activity Coefficient as A Deviation from Henry's Law
  247. 16.06: Henry's Law and the Hypothetical One-molal Standard State
  248. 16.07: Finding the Activity of a Solute from the Activity of the Solvent
  249. 16.08: When the Solute Obeys Henry's Law the Solvent Obeys Raoult's Law
  250. 16.09: Properties of Ideal Solutions
  251. 16.10: Colligative Properties - Boiling-point Elevation
  252. 16.11: Colligative Properties - Freezing-point Depression
  253. 16.12: Colligative Properties - Osmotic Pressure
  254. 16.13: Colligative Properties - Solubility of a Solute in an Ideal Solution
  255. 16.14: Colligative Properties - Solubility of a Gas
  256. 16.15: Solvent Activity Coefficients from Freezing-point Depression Measurements
  257. 16.16: Electrolytic Solutions
  258. 16.17: Activities of Electrolytes - The Mean Activity Coefficient
  259. 16.18: Activities of Electrolytes - The Debye-Huckel Theory
  260. 16.19: Finding Solute Activity Using the Hypothetical One-molal Standard State
  261. 16.20: Problems
  262. 17: Electrochemistry
  263. 17.01: Oxidation-reduction Reactions
  264. 17.02: Electrochemical Cells
  265. 17.03: Defining Oxidation States
  266. 17.04: Balancing Oxidation-reduction Reactions
  267. 17.05: Electrical Potential
  268. 17.06: Electrochemical Cells as Circuit Elements
  269. 17.07: The Direction of Electron Flow and its Implications
  270. 17.08: Electrolysis and the Faraday
  271. 17.09: Electrochemistry and Conductivity
  272. 17.10: The Standard Hydrogen Electrode (S.H.E)
  273. 17.11: Half-reactions and Half-cells
  274. 17.12: Standard Electrode Potentials
  275. 17.13: Predicting the Direction of Spontaneous Change
  276. 17.14: Cell Potentials and the Gibbs Free Energy
  277. 17.15: The Nernst Equation
  278. 17.16: The Nernst Equation for Half-cells
  279. 17.17: Combining two Half-cell Equations to Obtain a new Half-cell Equation
  280. 17.18: The Nernst Equation and the Criterion for Equilibrium
  281. 17.19: Problems
  282. 18: Quantum Mechanics and Molecular Energy Levels
  283. 18.01: Energy Distributions and Energy Levels
  284. 18.02: Quantized Energy - De Broglie's Hypothesis and the Schroedinger Equation
  285. 18.03: The Schrodinger Equation for A Particle in A Box
  286. 18.04: The Schrodinger Equation for a Molecule
  287. 18.05: Solutions to Schroedinger Equations for Harmonic Oscillators and Rigid Rotors
  288. 18.06: Wave Functions Quantum States Energy Levels and Degeneracies
  289. 18.07: Particle Spins and Statistics- Bose-Einstein and Fermi-Dirac Statistics
  290. 19: The Distribution of Outcomes for Multiple Trials
  291. 19.01: Distribution of Results for Multiple Trials with Two Possible Outcomes
  292. 19.02: Distribution of Results for Multiple Trials with Three Possible Outcomes
  293. 19.03: Distribution of Results for Multiple Trials with Many Possible Outcomes
  294. 19.04: Stirling's Approximation
  295. 19.05: Problems
  296. 20: Boltzmann Statistics
  297. 20.01: The Independent-Molecule Approximation
  298. 20.02: The Probability of An Energy Level at Constant N V and T
  299. 20.03: The Population Sets of a System at Equilibrium at Constant N V and T
  300. 20.04: How can Infinitely Many Probabilities Sum to Unity
  301. 20.05: The Total Probability Sum at Constant N V and T
  302. 20.06: The Most Probable Population Set at Constant N V and T
  303. 20.07: The Microstates of a Given Population Set
  304. 20.08: The Probabilities of Microstates that Have the Same Energy
  305. 20.09: The Probabilities of the Population Sets of an Isolated System
  306. 20.10: Entropy and Equilibrium in an Isolated System
  307. 20.11: Thermodynamic Probability and Equilibrium in an Isomerization Reaction
  308. 20.12: The Degeneracy of an Isolated System and Its Entropy
  309. 20.13: The Degeneracy of an Isolated System and its Entropy
  310. 20.14: Effective Equivalence of the Isothermal and Constant-energy Conditions
  311. 20.15: Problems
  312. 21: The Boltzmann Distribution Function
  313. 21.01: Finding the Boltzmann Equation
  314. 21.02: Lagrange's Method of Undetermined Multipliers
  315. 21.03: Deriving the Boltzmann Equation I
  316. 21.04: Deriving the Boltzmann Equation II
  317. 21.05: Partition Functions and Equilibrium - Isomeric Molecules
  318. 21.06: Finding and the Thermodynamic Functions for Distinguishable Molecules
  319. 21.07: The Microscopic Model for Reversible Change
  320. 21.08: The Third Law of Thermodynamics
  321. 21.09: The Partition Function for a System of N Molecules
  322. 21.10: Problems
  323. 22: Some Basic Applications of Statistical Thermodynamics
  324. 22.01: Interpreting the Partition Function
  325. 22.02: Conditions under which Integrals Approximate Partition Functions
  326. 22.03: Probability Density Functions from the Energies of Classical-mechanical Models
  327. 22.04: Partition Functions and Average Energies at High Temperatures
  328. 22.05: Energy Levels for a Three-dimensional Harmonic Oscillator
  329. 22.06: Energy and Heat Capacity of the Einstein Crystal
  330. 22.07: Applications of Other Entropy Relationships
  331. 22.08: Problems
  332. 23: The Ensemble Treatment
  333. 23.01: Ensembles of N-molecule Systems
  334. 23.02: The Ensemble Entropy and the Value of
  335. 23.03: The Thermodynamic Functions of the N-molecule System
  336. 24: Indistinguishable Molecules - Statistical Thermodynamics of Ideal Gases
  337. 24.01: The Partition Function for N Distinguishable Non-interacting Molecules
  338. 24.02: The Partition Function for N Indistinguishable Non-interacting Molecules
  339. 24.03: Occupancy Probabilities for Translational Energy Levels
  340. 24.04: The Separable-modes molecular Model
  341. 24.05: The Partition Function for A Gas of Indistinguishable Non-interacting Separable-modes Molecules
  342. 24.06: The Translational Partition Function of An Ideal Gas
  343. 24.07: The Electronic Partition Function of an Ideal Gas
  344. 24.08: The Vibrational Partition Function of A Diatomic Ideal Gas
  345. 24.09: The Rotational Partition Function of A Diatomic Ideal Gas
  346. 24.10: The Gibbs Free Energy for One Mole of An Ideal Gas
  347. 24.11: The Standard Gibbs Free Energy for H(g) I(g) and HI(g)
  348. 24.12: The Gibbs Free Energy Change for Forming HI(g) from H(g) and I(g)
  349. 24.13: The Reference State for Molecular Partition Functions
  350. 24.14: Problems
  351. 25: Bose-Einstein and Fermi-Dirac Statistics
  352. 25.01: Quantum Statistics
  353. 25.02: Fermi-Dirac Statistics and the Fermi-Dirac Distribution Function
  354. 25.03: Bose-Einstein Statistics and the Bose-Einstein Distribution Function
  355. 26: Appendices
  356. 26.01: Appendix A. Standard Atomic Weights 1999
  357. 26.02: Appendix B.
  358. 26.03: Appendix B. Fundamental Constants
  359. 26.04: Appendix C.
  360. 26.05: Units and Conversion Factors
  361. 26.06: Appendix D.
  362. 26.07: Appendix D. Some Important Definite Integrals