Introduzione al laboratorio di chimica organica

INTRODUZIONE AL LABORATORIO DI CHIMICA ORGANICA


Introduzione al laboratorio di chimica organica



Introduzione al laboratorio di chimica organica


INDICE
IL LABORATORIO DI CHIMICA ORGANICA
LA SICUREZZA IN LABORATORIO
ATTREZZATURA DI USO COMUNE
NEL LABORATORIO DI CHIMICA ORGANICA
E SUO IMPIEGO
METODI DI SEPARAZIONE E
DI IDENTIFICAZIONE DI SOSTANZE ORGANICHE
Filtrazione
Cristallizzazione
Cristallizzazione del p-chinone
Estrazione di soluzioni e di solidi
Separazione dell'acido benzoico dal Sudan Red 7B
Estrazione in continuo
Distillazione
Cromatografia
Cromatografia su strato sottile
Cromatografia in colonna
Esperienze pratiche di cromatografia in colonna e TLC
Sublimazione
Purificazione dell’acido benzoico per sublimazione
Punto di fusione
Determinazione del punto di fusione di miscele
- Polarimetro
Mutarotazione del glucosio
ANALISI QUALITATIVA ORGANICA
Prove di combustione e arroventamento
Ricerca degli alogeni
Ricerca dell'azoto
Prove di solubilitΰ in basi e acidi
Riconoscimento di composti insaturi
Riconoscimento di atomi di alogeno idrolizabili
Ossidazione con acido cromico
Reazione con 2,4-dinitrofenilidrazina
Saggio dello iodoformio
Reazione con cloruro ferrico
3
Questa Introduzione al laboratorio di chimica organica intende rivolgersi agli studenti di quei corsi di laurea (in Scienze naturali, in Scienze biologiche, ecc.) i quali, pur sostenendo un esame di chimica organica, frequentano il corrispondente laboratorio per un periodo molto piω breve rispetto a studenti di altri corsi di laurea. La loro conoscenza della chimica organica resta prevalentemente teorica e allorche', nel corso della loro carriera, si troveranno a contatto con un chimico organico, essi si accorgeranno di parlare talvolta due "linguaggi" completamente diversi.
Scopo delle presenti dispense θ quindi essenzialmente presentare alcune delle piω
comuni e semplici operazioni effettuate in un laboratorio di chimica organica, e di
rammentare i principi teorici che ad esse sottendono. Di proposito si dice "rammentare" poiche' tali concetti sono compiutamente svolti in altri insegnamenti e dovrebbero
essere considerati giΰ acquisiti dallo studente.
Tali principi vengono subito dopo applicati ad esperimenti pratici semplici e
dettagliatamente descritti, nella speranza che lo studente possa piω facilmente acquisire quella familiaritΰ e quella "manualitΰ" cosμ utili a chi debba frequentare un laboratorio di chimica organica in modo appena piω che occasionale.
Queste dispense non hanno, chiaramente, l'intenzione di essere un trattato di chimica organica, analitica, strumentale o un completo manuale di laboratorio; tali testi esistono giΰ e ad essi gli studenti interessati sono invitati a rivolgersi per ottenere nozioni e particolari che qui non sono presenti.
Si ringraziano fin d'ora tutti gli utenti di queste dispense per le critiche ed i suggerimenti che vorranno sottoporre al compilatore.

Introduzione al laboratorio di chimica organica

Mathematical Crystallography

Mathematical Crystallography
Worked examples in the
Geometry of Crystals
Fellow of Darwin College, Cambridge

Mathematical Crystallography

DOWNLOAD PDF

Mathematical Crystallography
Preface
First Edition
A large part of crystallography deals with the way in which atoms are arranged in single crystals.
On the other hand, a knowledge of the relationships between crystals in a polycrystalline
material can be fascinating from the point of view of materials science. It is this aspect of
crystallography which is the subject of this monograph. The monograph is aimed at both
undergraduates and graduate students and assumes only an elementary knowledge of crystallography.
Although use is made of vector and matrix algebra, readers not familiar with these
methods should not be at a disadvantage after studying appendix 1. In fact, the mathematics necessary for a good grasp of the subject is not very advanced but the concepts involved can be difficult to absorb. It is for this reason that the book is based on worked examples, which are intended to make the ideas less abstract.
Due to its wide–ranging applications, the subject has developed with many different schemes for notation and this can be confusing to the novice. The extended notation used throughout this text was introduced first by Mackenzie and Bowles; I believe that this is a clear and unambiguous scheme which is particularly powerful in distinguishing between representations of deformations and axis transformations.
The monograph begins with an introduction to the range of topics that can be handled using the concepts developed in detail in later chapters. The introduction also serves to familiarise the reader with the notation used. The other chapters cover orientation relationships, aspects of deformation, martensitic transformations and interfaces. In preparing this book, I have benefited from the support of Professors R. W. K. Honeycombe, Professor D. Hull, Dr F. B. Pickering and Professor J. Wood. I am especially grateful to Professor J. W. Christian and Professor J. F. Knott for their detailed comments on the text,
and to many students who have over the years helped clarify my understanding of the subject.
It is a pleasure to acknowledge the unfailing support of my family.
April 1986
Second Edition
I am delighted to be able to publish this revised edition in electronic form for free access. It is
a pleasure to acknowledge valuable comments by Steven Vercammen.
January 2001, updated July 2008

Contents
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Definition of a Basis . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Co-ordinate transformations . . . . . . . . . . . . . . . . . . . 3
The reciprocal basis . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Homogeneous deformations . . . . . . . . . . . . . . . . . . . . .6
Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
ORIENTATION RELATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Cementite in Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Relations between FCC and BCC crystals . . . . . . . . . . . . . . . . . . . 16
Orientation relations between grains of identical structure . . . . . . .19
The metric . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
More about the vector cross product . . . . . . . . . . . . . . . . . . . . . . 24
SLIP, TWINNING AND OTHER INVARIANT-PLANE STRAINS . . . . . . . . . . . . . . . 25
Deformation twins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
The concept of a Correspondence matrix . . . . . . . . . . . . . . . . . . . . 35
Stepped interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Eigenvectors and eigenvalues . . . . . . . . . . . . . . . . . . . . . . . . .39
Stretch and rotation . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Conjugate of an invariant-plane strain . . . . . . . . . . . . . . . . . . . 48
MARTENSITIC TRANSFORMATIONS . . . . . . . . . . . . . . . . . . . . . . . . . .51
The diffusionless nature of martensitic transformations . . . . . . . . . . .51
The interface between the parent and product phases . . . . . . . . . . . . . .51
Orientation relationships . . . . . . . . . . . . . . . . . . . . . . .54
The shape deformation due to martensitic transformation . . . . . . . . . . .55
The phenomenological theory of martensite crystallography . . . . . . . . . 57
INTERFACES IN CRYSTALLINE SOLIDS . . . . . . . . . . . . . . . 70
Symmetrical tilt boundary . . . . . . . . . . . . . . . 73
The interface between alpha and beta brass . . . . 75
Coincidence site lattices . . . . . . . . . . . . . . . . . . . 76
Multitude of axis-angle pair representations . . . . .79
The O-lattice . . . . . . . 82
Secondary dislocations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85
The DSC lattice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Some difficulties associated with interface theory . . . . . . . . . . . . . . . .89
APPENDIX 1: VECTORS AND MATRICES . . . . . . . . . . . . . . . . . . . . . . . . 91
APPENDIX 2: TRANSFORMATION TEXTURE . . . . . . . . . . . . . . . . . . . . . . . .96
APPENDIX 3: TOPOLOGY OF GRAIN DEFORMATION . . . . . . . . . . . . . . . . . . . .100
REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

Honors General Chemistry - Course Notes

Honors General Chemistry - Course Notes


Chemistry 138 - Course Notes

Contents
I The Microscopic 1
1 Quantum Theory 2
1.1 Electromagnetic Radiation . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 The “Fall” of Classical Physics . . . . . . . . . . . . . . . . . . . . . 6
1.3 Bohr’s Atomic Theory . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.3.1 First attempts at the structure of the atom. . . . . . . . . . 7
1.4 The Postulates ofQuantumMechanics . . . . . . . . . . . . . . . . 11
1.4.1 TheHamiltonian . . . . . . . . . . . . . . . . . . . . . . . . 12
1.4.2 TheHeisenberg Uncertainty Principle . . . . . . . . . . . . . 13
2 Quantum Models 15
2.1 Particle in a Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2 The HarmonicOscillator . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2.1 Interesting Aspects of the Quantum Harmonic Oscillator . . 21
2.3 TheMorseOscillator . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2.4 Rigid Rotor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3 Atoms 26
3.1 The Hydrogen Atom . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.1.1 The quantumnumbers of the hydrogen system . . . . . . . . 27
i
3.1.2 The energy levels . . . . . . . . . . . . . . . . . . . . . . . . 28
3.1.3 Ground and excited states . . . . . . . . . . . . . . . . . . . 28
3.2 TheOther Atoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.2.1 The Pauli exclusion principle . . . . . . . . . . . . . . . . . 30
3.2.2 Electronic configurations of atoms . . . . . . . . . . . . . . . 31
3.3 Periodic Properties of the Atoms . . . . . . . . . . . . . . . . . . . 32
4 Fundamentals of Chemical Bonding 35
4.1 Valence Electrons . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
4.1.1 Lewis dot structures . . . . . . . . . . . . . . . . . . . . . . 36
4.2 Chemical Bond Formation . . . . . . . . . . . . . . . . . . . . . . . 37
4.3 Properties of the Chemical Bond . . . . . . . . . . . . . . . . . . . 39
4.4 ChargeDistribution in Covalent Compounds . . . . . . . . . . . . . 40
4.4.1 Formal charge . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.4.2 Electronegativity and bond polarity . . . . . . . . . . . . . . 41
5 Chemical Bonding: Valence Bond Theory 44
5.1 VSEPR Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
5.2 Valence Bond Theory . . . . . . . . . . . . . . . . . . . . . . . . . . 45
5.2.1 Multiple Bonds . . . . . . . . . . . . . . . . . . . . . . . . . 46
5.2.2 Hybridization . . . . . . . . . . . . . . . . . . . . . . . . . . 46
6 Molecular Spectroscopy 48
6.1 The Born—Oppenheimer Approximation. . . . . . . . . . . . . . . . 48
6.2 Molecular Energy Levels . . . . . . . . . . . . . . . . . . . . . . . . 49
6.2.1 The electronic energy levels . . . . . . . . . . . . . . . . . . 50
6.2.2 The vibrational levels . . . . . . . . . . . . . . . . . . . . . . 51
6.2.3 The rotational levels . . . . . . . . . . . . . . . . . . . . . . 51
ii
6.2.4 Putting it all together . . . . . . . . . . . . . . . . . . . . . 51
6.3 Spectroscopy ofMolecules . . . . . . . . . . . . . . . . . . . . . . . 52
6.3.1 Absorption Spectra . . . . . . . . . . . . . . . . . . . . . . . 53
6.3.2 Fluorescence (or emission) Spectra . . . . . . . . . . . . . . 54
II The Macroscopic 56
7 Rudiments of Statistical Mechanics 57
7.1 Probability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
7.1.1 Algebra for Probabilities . . . . . . . . . . . . . . . . . . . . 58
7.1.2 Factorials . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
7.1.3 Combinations and Permutations . . . . . . . . . . . . . . . . 62
7.2 Statistics and Entropy . . . . . . . . . . . . . . . . . . . . . . . . . 63
7.3 The BoltzmannDistribution . . . . . . . . . . . . . . . . . . . . . . 64
7.4 Partition Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
7.4.1 EnsembleAverages . . . . . . . . . . . . . . . . . . . . . . . 68
7.4.2 Relation between the Q and W . . . . . . . . . . . . . . . . 69
7.5 TheMolecular Partition Function . . . . . . . . . . . . . . . . . . . 70
8 Gases 75
8.1 The IdealGas Law . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
8.2 GasMixtures and Partial Pressure . . . . . . . . . . . . . . . . . . 77
8.3 Chemical Reactions BetweenGases . . . . . . . . . . . . . . . . . . 79
8.4 TheKineticMolecular Theory ofGases . . . . . . . . . . . . . . . . 80
9 The Zeroth and First Laws of Thermodynamics 82
9.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
9.1.1 Types of Systems . . . . . . . . . . . . . . . . . . . . . . . . 83
iii
9.1.2 System Parameters (or properties) . . . . . . . . . . . . . . 83
9.2 Work and Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
9.2.1 P V work. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
9.2.2 MaximalWork: Reversible versus Irreversible changes . . . . 86
9.2.3 Heat Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . 88
9.3 Equations of State . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
9.3.1 Example 1: The IdealGas Law . . . . . . . . . . . . . . . . 90
9.3.2 Example 2: The van derWaals Equation of State . . . . . . 91
9.4 Temperature and the Zeroth Law of Thermodynamics . . . . . . . . 91
9.5 The First Law of Thermodynamics . . . . . . . . . . . . . . . . . . 93
9.5.1 The internal energy state function . . . . . . . . . . . . . . . 93
9.6 Calorimetry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
9.7 Hess’ Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
10 Entropy and the Second and Third Laws of Thermodynamics 99
10.0.1 Statements of the Second Law . . . . . . . . . . . . . . . . . 101
10.1 Calculation of Entropy . . . . . . . . . . . . . . . . . . . . . . . . . 102
10.1.1 Entropy change for changes in temperature. . . . . . . . . . 102
10.1.2 Isothermal expansion of an ideal gas: . . . . . . . . . . . . . 102
10.1.3 Entropy ofMixing of an ideal gas . . . . . . . . . . . . . . . 103
10.2 The Third Law of Thermodynamics . . . . . . . . . . . . . . . . . . 104
10.2.1 The Third Law . . . . . . . . . . . . . . . . . . . . . . . . . 104
10.3 Time’s Arrow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
11 Equilibrium 107
11.1 TheOther Important State Functions of Thermodynamics . . . . . 107
11.2 Enthalpy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
iv
11.2.1 Heuristic definition: . . . . . . . . . . . . . . . . . . . . . . . 111
11.2.2 Hess’ Law revisited . . . . . . . . . . . . . . . . . . . . . . . 111
11.3 Helmholtz Free Energy . . . . . . . . . . . . . . . . . . . . . . . . . 114
11.3.1 Heuristic definition: . . . . . . . . . . . . . . . . . . . . . . . 115
11.4 Gibbs Free Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
11.4.1 Heuristic definition: . . . . . . . . . . . . . . . . . . . . . . . 116
11.5 Spontaneity of processes . . . . . . . . . . . . . . . . . . . . . . . . 116
11.6 Chemical potential . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
11.6.1 Reference States . . . . . . . . . . . . . . . . . . . . . . . . 118
11.6.2 Chemical potential and solutions . . . . . . . . . . . . . . . 119
11.7 General Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . 120
11.7.1 Free EnergyDiagrams . . . . . . . . . . . . . . . . . . . . . 123
11.7.2 An Example: The Partition Coefficient . . . . . . . . . . . . 125
12 Electrochemistry 127
12.1 Oxidation—Reduction (Redox) Reactions . . . . . . . . . . . . . . . 127
12.1.1 Balancing redox reactions . . . . . . . . . . . . . . . . . . . 129
12.2 Electrochemical Cells . . . . . . . . . . . . . . . . . . . . . . . . . . 129
12.2.1 Cell diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . 130
12.2.2 Cell potentials . . . . . . . . . . . . . . . . . . . . . . . . . . 131
12.2.3 Reversible emf and free energy . . . . . . . . . . . . . . . . . 131
12.2.4 The standard emf . . . . . . . . . . . . . . . . . . . . . . . . 132
12.3 Concentration Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
12.3.1 Membrane Potentials . . . . . . . . . . . . . . . . . . . . . . 134
Honors General Chemistry, Course Notes

General Chemistry I - Chemistry 127

General Chemistry I - Chemistry 127



General Chemistry I - Chemistry 127


Lecture Notes
Chemistry 127: General Chemistry I
These notes are designed to cover what I will be writing on the board during
the video lectures. You should have these notes in front of you when you
watch. The idea is to give you more time to think about what is being said
rather than scrambling to write down the notes. One disadvantage is that it
may be easier to gap out for awhile. To get the most out of video lectures you
will want to avoid this. Also, try to find a dedicated place and time to watch
without disctraction. In the videos I will say things that are in addition to
the notes so you will want to write those things down as well. The notes are
organized such that each chapter is a lecture. Watching the video lectures as
part of your study time for this class will leave the class time for more active
learning with group work and other in-class activities. It can not be stressed
enough that the group work is as important or even more important than the
lecture itself. Some problems you work on in groups will introduce concepts
that we do not discuss in lecture. You will be expected to know the group
material at the same level as the lecture material when it comes time for the
exams. So, make sure that you as an individual understand what your group
is discussing. Finally, the problem sets for each lecture are given at the end
of each section. These problems are due at the beginning of the next lecture
period.

Contents
1 LectureL1: Introduction 1
2 Physical and Chemical Properties 3
2.1 Matter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1.1 Pure Substances andMixtures . . . . . . . . . . . . . . 4
2.2 Elements, Compounds andMolecules . . . . . . . . . . . . . . 4
2.3 Physical Properties ofMatter . . . . . . . . . . . . . . . . . . 5
2.3.1 Extensive and Intensive Properties . . . . . . . . . . . 6
2.4 Physical and Chemical Changes . . . . . . . . . . . . . . . . . 6
2.5 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.6 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3 Measurement 10
3.1 Units ofMeasure . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1.1 Reporting Numbers . . . . . . . . . . . . . . . . . . . . 12
3.2 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3.3 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4 Anatomy of the Atom and the Periodic Table 18
4.1 Basic Structure of the Atom . . . . . . . . . . . . . . . . . . . 18
4.2 Atomic Number, AtomicMass and Isotopes . . . . . . . . . . 19
4.2.1 Atomic number . . . . . . . . . . . . . . . . . . . . . . 19
4.2.2 Atomicmass and atomicmass number . . . . . . . . . 19
4.2.3 Isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.3 The Periodic Table . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3.1 Group 1A . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3.2 Group 2A . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3.3 The B groups . . . . . . . . . . . . . . . . . . . . . . . 21
4.3.4 Group 3A . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.3.5 Group 4A . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.3.6 Group 5A . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.3.7 Group 6A . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.3.8 Group 7A . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.3.9 Group 8A . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.4 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
4.5 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5 TheMole 25
5.1 TheMole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2 MolarMass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
5.2.1 Converting between grams andmoles . . . . . . . . . . 26
5.2.2 Percent Composition . . . . . . . . . . . . . . . . . . . 26
5.2.3 Empirical formula . . . . . . . . . . . . . . . . . . . . . 27
5.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6 Molecules and Compounds 30
6.1 Chemical Formula . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.2 NamingMolecules . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.3 GroupWork: . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
6.4 ProblemSet: . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
7 Ions and Ionic Compounds 34
7.1 OxidationNumber . . . . . . . . . . . . . . . . . . . . . . . . 34
7.2 Polyatomic Ions . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.3 Ionic Compounds . . . . . . . . . . . . . . . . . . . . . . . . . 36
7.3.1 Naming Ionic Compounds . . . . . . . . . . . . . . . . 36
7.4 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
7.5 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8 Chemical Equations and Stoichiometry 40
8.1 Balancing Equations . . . . . . . . . . . . . . . . . . . . . . . 41
8.2 Quantitative Relations in Chemical Reactions . . . . . . . . . 42
8.3 Mass Relations in Chemical Reactions . . . . . . . . . . . . . 42
8.4 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
8.5 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
9 Limiting Reagents 47
9.1 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
9.2 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
10 Net Ionic Equations 51
10.1 Ions in Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 51
10.1.1 Electrolytes . . . . . . . . . . . . . . . . . . . . . . . . 52
10.2 PrecipitationReactions . . . . . . . . . . . . . . . . . . . . . . 52
10.3 Net Ionic Equations . . . . . . . . . . . . . . . . . . . . . . . . 53
10.4 Acids and Bases . . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.4.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 53
10.4.2 AWord on the Hydrogen Ion . . . . . . . . . . . . . . 54
10.4.3 Reactions of Acids and Bases . . . . . . . . . . . . . . 55
10.5 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
10.6 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
11 Redox Reactions 58
11.0.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 58
11.0.2 Redox reactions . . . . . . . . . . . . . . . . . . . . . . 58
11.1 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
11.2 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
12 Concentration and Molarity 62
12.1 Concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
12.2 Molarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
12.3 pH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
12.4 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
12.5 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
13 Titration Reactions 68
13.1 Titrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
13.2 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
13.3 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
14 Energy, Heat and the First Law of Thermodynamics 72
14.1 Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
14.1.1 Conservation of energy . . . . . . . . . . . . . . . . . . 72
14.1.2 Work and heat . . . . . . . . . . . . . . . . . . . . . . 73
14.2 The First Lawof Thermodynamics . . . . . . . . . . . . . . . 73
14.3 Temperature andHeat . . . . . . . . . . . . . . . . . . . . . . 73
14.3.1 Heat capacity . . . . . . . . . . . . . . . . . . . . . . . 73
14.4 Phase Changes . . . . . . . . . . . . . . . . . . . . . . . . . . 74
14.5 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
14.6 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
15 Enthalpy 77
15.1 Work and the First Law . . . . . . . . . . . . . . . . . . . . . 77
15.2 Enthalpy Changes for Reactions . . . . . . . . . . . . . . . . . 78
15.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
15.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
16 Lecture L19: Calorimetry 81
16.1 Calorimetry and Heats of Combustions . . . . . . . . . . . . . 81
16.1.1 Example . . . . . . . . . . . . . . . . . . . . . . . . . . 82
16.2 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
16.3 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
17 Hess’ Law 85
17.1 State Functions . . . . . . . . . . . . . . . . . . . . . . . . . . 85
17.2 Hess’ Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
17.2.1 Heats of formation . . . . . . . . . . . . . . . . . . . . 86
17.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
17.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
18 Light 91
18.1 Electromagnetic Radiation . . . . . . . . . . . . . . . . . . . . 91
18.2 The PhotonDescription . . . . . . . . . . . . . . . . . . . . . 92
18.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
18.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
19 The Fall of Classical Physics and the Bohr Model 96
19.1 Brief Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 96
19.2 Bohr’s Atomic Theory . . . . . . . . . . . . . . . . . . . . . . 97
19.2.1 First attempts at the structure of the atom. . . . . . . 97
19.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
19.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
20 Atomic Orbitals 103
20.1 TheModern Theory of the HydrogenAtom . . . . . . . . . . 103
20.2 TheQuantumNumbers of the HydrogenAtom. . . . . . . . . 104
20.3 Visualizing the AtomicOrbitals . . . . . . . . . . . . . . . . . 105
20.4 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
20.5 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
21 Multielectron Atoms and the Pauli Exclusion Principle 109
21.1 TheOther Atoms . . . . . . . . . . . . . . . . . . . . . . . . . 109
21.2 The Pauli Exclusion Principle . . . . . . . . . . . . . . . . . . 110
21.3 Electronic Configurations of Atoms . . . . . . . . . . . . . . . 110
21.4 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
21.5 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
22 Periodic Trends 114
22.1 Periodic Properties of the Atoms . . . . . . . . . . . . . . . . 114
22.2 Shielding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
22.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
22.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
23 Lewis Dot Structures I 118
23.1 Fundamentals of Chemical Bonding . . . . . . . . . . . . . . . 118
23.2 Valence Electrons . . . . . . . . . . . . . . . . . . . . . . . . . 118
23.3 LewisDot Structures . . . . . . . . . . . . . . . . . . . . . . . 118
23.4 Chemical Bond Formation . . . . . . . . . . . . . . . . . . . . 119
23.5 AlgorithmforDrawing Lewis Structures . . . . . . . . . . . . 122
23.6 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
23.7 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
24 Lewis Dot Structure II 125
24.1 Formal Charge . . . . . . . . . . . . . . . . . . . . . . . . . . 125
24.2 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
24.3 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
25 Properties of Chemical Bonds 128
25.1 Properties of the Chemical Bond . . . . . . . . . . . . . . . . 128
25.2 ChargeDistribution in Covalent Compounds . . . . . . . . . . 129
25.2.1 Electronegativity and bond polarity . . . . . . . . . . . 129
25.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
25.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
26 The VSEPR Model 131
26.1 VSEPRModel . . . . . . . . . . . . . . . . . . . . . . . . . . 131
26.2 MolecularDipoleMoments . . . . . . . . . . . . . . . . . . . . 133
26.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
26.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133
27 Valence Bond Theory 136
27.1 Valence Bond Theory . . . . . . . . . . . . . . . . . . . . . . . 136
27.2 Multiple Bonds . . . . . . . . . . . . . . . . . . . . . . . . . . 137
27.3 Hybridization . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
27.4 Multiple Bonds Revisited . . . . . . . . . . . . . . . . . . . . . 139
27.5 Representing the 3Dstructure ofmolecules . . . . . . . . . . . 139
27.6 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
27.7 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
28 Symmetry 143
28.1 Symmetry Elements . . . . . . . . . . . . . . . . . . . . . . . 143
28.2 Symmetry PointGroups . . . . . . . . . . . . . . . . . . . . . 144
28.3 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
29 Intermolecular Forces 146
29.1 Polarizability and Induced Dipoles . . . . . . . . . . . . . . . 146
29.2 Intermolecular Forces . . . . . . . . . . . . . . . . . . . . . . . 147
29.3 PhaseDiagrams . . . . . . . . . . . . . . . . . . . . . . . . . . 149
30 Hydrogen Bonding and Water 151
30.1 Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
30.1.1 TheGrotthussmechanism . . . . . . . . . . . . . . . . 153
30.2 Acids and Bases Revsited . . . . . . . . . . . . . . . . . . . . 153
30.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
30.4 Homework . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
31 Ideal Gases I 156
31.1 Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
31.2 The Ideal Gas Law . . . . . . . . . . . . . . . . . . . . . . . . 156
31.2.1 Aword on units . . . . . . . . . . . . . . . . . . . . . . 157
31.2.2 Ideal gas law in terms of density . . . . . . . . . . . . . 158
31.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
31.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
32 Ideal Gases II 161
32.1 GasMixtures and Partial Pressure . . . . . . . . . . . . . . . 161
32.2 Chemical Reactions BetweenGases . . . . . . . . . . . . . . . 162
32.3 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163
32.4 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
33 Kinetic Theory of Gases 166
33.1 TheKineticMolecular Theory ofGases . . . . . . . . . . . . . 166
33.2 GroupWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
33.3 ProblemSet . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Lecture Notes
Chemistry 127: General Chemistry I

Cinetica Chimica

Universitΰ degli Studi di Bari
Laurea Magistrale in Biotecnologie

Cinetica Chimica

Cinetica Chimica

Cinetica chimica applicata

POLITECNICO DI MILANO
Corso di Laurea in Ingegneria Chimica
Dipartimento di Chimica e de Materiali Natta

Cinetica chimica applicata

Cinetica chimica applicata


Indice
1 Isoterme 1
1.1 Isoterma B.E.T. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Isoterma di Langmuir . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.3 Meccanismo LHHW . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Teoria cinetica dei gas 9
2.1 Ipotesi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Energia cinetica del gas . . . . . . . . . . . . . . . . . . . . . . . . 9
2.3 Frequenza d’urto tra due particelle . . . . . . . . . . . . . . . . . . 11
2.4 Distribuzione della velocit`a secondo Boltzman . . . . . . . . . . . . 12
3 Meccanica quantistica 17
3.1 Operatori e le loro propriet`a . . . . . . . . . . . . . . . . . . . . . . 19
3.2 Assiomi della quantomeccanica . . . . . . . . . . . . . . . . . . . . 20
3.2.1 La funzione d’onda . . . . . . . . . . . . . . . . . . . . . . . 20
3.2.2 Gli osservabili . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2.3 Il valore medio . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2.4 La probabilit`a . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.2.5 L’equazione di Schr¨odinger . . . . . . . . . . . . . . . . . . 21
3.3 L’equazione di Schr¨odinger . . . . . . . . . . . . . . . . . . . . . . 21
3.4 L’equazione di Schr¨odinger indipendente dal tempo . . . . . . . . . 22
3.5 Particella in una scatola di potenziale monodimensionale . . . . . . 23
3.5.1 Particella in una buca di potenziale tridimensionale . . . . 25
3.6 Oscillatore armonico monodimensionale . . . . . . . . . . . . . . . 26
4 Termodinamica statistica 31
4.1 Postulati della termodinamica statistica . . . . . . . . . . . . . . . 32
4.2 Sistema a contatto con bagno termico . . . . . . . . . . . . . . . . 32
4.3 Applicazione alla termodinamica . . . . . . . . . . . . . . . . . . . 33
4.4 Funzione di partizione molecolare . . . . . . . . . . . . . . . . . . . 36
4.4.1 Contributo elettronico . . . . . . . . . . . . . . . . . . . . . 36
4.4.2 Contributo traslazionale . . . . . . . . . . . . . . . . . . . . 37
4.4.3 Contributo vibrazionale . . . . . . . . . . . . . . . . . . . . 38
4.4.4 Contributo rotazionale . . . . . . . . . . . . . . . . . . . . . 38
5 Teoria dello strato di transizione 39
5.1 Schema di una generica reazione . . . . . . . . . . . . . . . . . . . 39
5.2 Ipotesi restrittive . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.3 Velocit`a di reazione . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
5.3.1 Concentrazione della specie intermedia . . . . . . . . . . . . 41
5.3.2 Costante di equilibrio in funzione della funzione di partizione
molecolare . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
5.4 La costante cinetica . . . . . . . . . . . . . . . . . . . . . . . . . . 44
6 Reazioni in fase condensata 47
6.1 Teoria di Brψnsted-Bjerron . . . . . . . . . . . . . . . . . . . . . . 49
A Tabella degli integrali 51

Cinetica chimica applicata