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ADVANCED CHEMISTRY 1
Philip Matthews
B&& CAMBRIDGE UNIVERSITY PRESS
Contents
Acknowledgements
How to use this book
PHYSICAL CHEMISTRY
1 Elements, atoms and electrons: basic ideas
1.1 Dalton's atomic theory 1.2 Evidence for atoms 1.3 Cathode rays 1.4 Millikan's experiment 1.5 Electric Charge is quantised
2 Energy levels 2.1 Energy changes 2.2 Energy levels 2.3 Max Planck and energy levels 2.4 Light energy
3 Atoms and the nucleus 3.1 A plum pudding 3.2 How the nucleus was discovered 3.3 The discovery of protons 3.4 Moseley and atomic number 3.5 Discovery of neutrons 3.6 A comparison of electrons, protons and
neutrons 3.7 Isotopes 3.8 Atomic mass units 3.9 Relative atomic and molecular masses 3.10 Einstein's equation 3.11 Binding energy 3.12 Mass defect and mass excess
4 Discovery of radioactivity 4.1 The discovery of radioactivity 4.2 New elements 4.3 Some properties of radiation 4.4 Units of radioactivity 4.5 Nuclear reactions 4.6 Artificially prepared elements 4.7 A sad ending
pagex xi
3 3 5 6 6 7
9 9 9 11 11
13 13 13 14 15 15
16 17 17 18 18 20 21
23 23 24 24 25 25 26 27
5 5.1 5.2 5.3 5.4
6 6.1 6.2 6.3 6.4 6.5
7 7.1 7.2 7.3 7.4
8 8.1 8.2
8.3 8.4 8.5
9 9.1 9.2 9.3
10 10.1
10.2 10.3
11 11.1
11.2 11.3 11.4
Radioactive decay 28 Detection of radiation 28 Half-lives 29 The radioactive decay law 31 Decay schemes 31
Nuclear energy 34 Discovery of nuclear energy 34 Fission reactions 34 Nuclear power 35 Fusion reactions 37 Nuclear weapons 38
Applications of radioactivity 41 Industrial uses of radioactivity 41 Medical uses of radioactivity 42 Radiocarbon dating 42 Chemical applications 43
Bohr's model of the atom 46 Energy levels of the hydrogen atom 46 How to calculate the ionisation energy of hydrogen 47 What are Orbitals? 48 What are stationary states? 48 Ground and excited states 49
The hydrogen atom spectrum 51 Balmer's formula for the hydrogen atom 51 Bohr's explanation 51 Other lines in the hydrogen spectrum 51
Waves and particles 54 Experimental evidence about the nature of light 54 What is wave—particle duality? 56 de Broglie's equation 56
Schrödinger's theory of the atom 58 Schrödinger's theory of the hydrogen atom 58 What do the quantum numbers teil us? 59 Different types of orbital 59 Wavefunctions and what they mean 60
11.5 The shapes of orbitals 11.6 The spin quantum number
12 The aufbau method and electron structures
12.1 What is the aufbau method? 12.2 More about orbital energies 12.3 Filling orbitals - the importance of energy 12.4 The Pauli exclusion principle 12.5 Hund's rule 12.6 Background to Hund's rule 12.7 The aufbau method in action
13 Electron structures, ionisation energies and shielding
13.1 What is shielding? 13.2 Ionisation energies down a Group 13.3 Ionisation energies across a Period 13.4 How ionisation energies are linked to
Groups in the Periodic Table
14 Bonding in molecules: valence bond theory
14.1 Valence bond theory 14.2 Dot-and-cross diagrams for diatomic
molecules 14.3 Dot-and-cross diagrams for triatomic and
quadratomic molecules 14.4 Dot-and-cross diagrams for hydrocarbons 14.5 Showing bonds by lines 14.6 Bonding in oxoanions 14.7 Resonance structures
15 Coordinate bonding 15.1 What is coordinate bonding?
16 Molecular orbital theory 16.1 Wavefunctions can be positive or
negative 16.2 How wavefunctions can be combined 16.3 Bonding and antibonding orbitals using s
orbitals 16.4 Bonding and antibonding orbitals using p
orbitals 16.5 Energies of bonding and antibonding
orbitals 16.6 Molecular orbitals for homopolar
diatomic molecules 16.7 Molecular orbitals for heteropolar
diatomic molecules 16.8 Molecular orbitals for hydrocarbons
17 Shapes of molecules 17.1 Molecular modeis 17.2 Electron repulsion theory 17.3 The isoelectronic rule 17.4 Hybridisation
18 Ionic bonding 18.1 Covalent substances have some ionic
character
61 63
66 66 66 67 67 68 68 68
71 71 71 72
18.2
18.3
18.4 18.5 18.6
19 19.1 19.2 19.3 19.4
20 20.1 20.2 20.3 20.4
73 20.5
77 77
78
78 79 79 80 80
84 84
87
87 87
87
88
89
90
91 92
95 95 95 96 97
101
101
21 21.1 21.2 21.3
21.4 21.5
22 22.1 22.2 22.3 22.4 22.5 22.6
23 23.1 23.2 23.3
23.4
23.5
24 24.1 24.2 24.3 24.4 24.5 24.6 24.7 24.8 24.9
25 25.1
Ionic substances have some covalent character 101 Other evidence that a substance contains ions 102 Which elements make ionic Compounds? 103 Why do ionic Compounds exist? 103 Ionic Compounds and electron structures 104
Polar molecules and polar bonds 107 What is a polar molecule? 107 Polar bonds and electronegativities 107 Polar molecules and dipole moments 108 Polarisability 111
Intermolecular forces 113 Where are intermolecular forces found? 113 What causes intermolecular forces? 113 Dispersion forces and polarisability 114 Intermolecular forces are also produced by permanent dipoles 114 Some words of warning 114
Hydrogen bonding 117 What is hydrogen bonding? 117 Evidence for hydrogen bonding 117 Intermolecular and intramolecular hydrogen bonding 119 Hydrogen bonding in biochemistry 120 Hydrogen bonding in solids 120
Metallic bonding 122 How can you recognise a metal? 122 What is the band structure of metals? 122 Why do metals conduct electricity? 123 Semiconductors 123 Why do metals conduct heat? 126 Metal atoms exist in a sea of electrons 126
The three states of matter 128 The three states of matter 128 How do we know that gases are disorderly? 129 Differences in properties of solids, liquids and gases 129 The potential energy curve for two neighbouring molecules 130 Some remarkable substances 130
Three types of spectroscopy 136 Emission and absorption spectra 136 Electronic spectroscopy 136 Vibrational spectroscopy 136 Rotational spectroscopy 136 Translations 138 Electromagnetic waves 138 The electric field and electrons 139 The magnetic field and electrons 139 Selection rules 140
Visible spectroscopy 142 Why does copper(n) sulphate Solution lookblue? 142
IV Contents
25.2 The visible spectrum of copper(n) sulphate Solution
25.3 How does a visible light spectrometer work?
25.4 What happens to the photons absorbed by copper(n) sulphate Solution?
25.5 Why vibrations are important in visible spectra
26 Ultraviolet spectroscopy 26.1 The ultra violet spectrum of alkenes 26.2 The ultraviolet spectrum of arenes 26.3 The ultraviolet spectrum of aldehydes
and ketones
27 Vibrational spectroscopy 27.1 Why is vibrational spectroscopy useful? 27.2 What are group frequencies? 27.3 Making sense of vibrational spectra 27.4 Vibrational spectra can teil us about the
strengths of bonds
28 Nuclear magnetic resonance 28.1 The importance of nuclear spin 28.2 The patterns in an n.m.r. spectrum 28.3 Why do protons appear in different
places in the spectrum? 28.4 N.m.r. spectra can teil us how many
protons are present 28.5 Not only hydrogen atoms can show up in
n.m.r.
29 Mass spectrometry 29.1 What are mass spectrometers? 29.2 The design of a mass spectrometer 29.3 The whole number rule and Standards of
mass 29.4 Mass spectra and isotopes 29.5 Calculating relative atomic masses from
mass spectra 29.6 What are fragmentation patterns? 29.7 The effect of isotopes in a molecule's mass
spectrum
30 X-ray diffraction 30.1 What causes X-ray diffraction? 30.2 More about diffraction 30.3 Bragg's equation 30.4 Different types of X-ray diffraction
experiment 30.5 Explanation of powder photographs 30.6 The arrangement of planes in crystals 30.7 The arrangements of individual atoms
31 Crystallography 31.1 What is crystallography? 31.2 The dosest packing of atoms 31.3 Structures that are not close-packed 31.4 C oordination numbers 31.5 Metal crystals
142
143
144
144
146 146 147
147
149 149 151 151
155
157 157 158
158
158
159
161 161 161
162 164
164 164
165
168 168 168 169
169 170 171 172
174 174 174 176 176 176
32 32.1 32.2 32.3 32.4 32.5
33 33.1
33.2 33.3 33.4 33.5
34 34.1 34.2
34.3
35 35.1 35.2 35.3
35.4 35.5
36 36.1 36.2 36.3 36.4
37 37.1 37.2 37.3 37.4 37.5
37.6
38 38.1 38.2
38.3
39 39.1 39.2 39.3 39.4
40 40.1
Unit cells 179 The seven crystal Systems 179 The fourteen Bravais lattices 179 What are unit cells? 179 Radius ratio rules 184 The number of atoms or ions in a unit cell 185
Sizes of atoms, ions and molecules 188 How can we estimate the size of an atom? 188 Metallic and covalent radii 188 Van der Waals radii 189 Ionic radii 190 Bondlengths 191
Real and ideal gases 193 The gas laws 193 Real gases and the van der Waals equation 195 How good is the van der Waals equation? 196
Kinetic theory of gases 200 What is the kinetic theory of gases? 200 The pressure of an ideal gas 200 The connection between energy and temperature 201 The spread of energies in a gas 202 Kinetic theory and Avogadro's theory 203
Chemistry and gases 205 Gay-Lussac's law of combining volumes 205 Avogadro's theory 205 Dalton's law of partial pressures 206 Graham's law of diffusion 206
The mole 209 What is the mole? 209 How to work with moles of Compounds 210 Moles and equations 210 Moles and balancing equations 211 The empirical formula and molecular formula of a Compound 212 Percentage compositions 213
Molar masses of gases and liquids 216 Measuring the molar mass of a gas 216 Measuring the molar mass of a soluble gas 217 Measuring the molar mass of a volatile liquid 218
Moles and titrations 221 Standard Solutions 221 The concentration of a Solution 223 Concentration and molarity 224 How to do calculations involving concentrations 224
Four types of titration 227 Acid-base titrations 227
Contents v
40.2 Redox titrations 40.3 Titrations involving iodine 40.4 Silver nitrate titrations
41 Oxidation numbers and oxidation states
41.1 What are oxidation and reduction reactions?
41.2 What are oxidation numbers? 41.3 Oxidation numbers of elements in
covalent Compounds 41.4 Oxidation numbers of elements in ions 41.5 Rules for assigning oxidation numbers 41.6 Oxidation states 41.7 Using oxidation numbers with equations 41.8 Half-equations
42 Energy changes 42.1 Energy changes and chemical bonds 42.2 Energy changes and energy diagrams 42.3 Exothermic and endothermic reactions
43 Enthalpy 43.1 What is enthalpy? 43.2 Enthalpy and Standard states 43.3 Enthalpy and State functions 43.4 Hess's law
44 Standard enthalpies 44.1 Standard enthalpy of an dement 44.2 Standard heats of formation 44.3 Standard heats of combustion 44.4 Enthalpy changes when substances break
apart 44.5 Bond energies and average bond energies 44.6 Heats of hydrogenation
45 Calculations using Hess's law 45.1 Using heats of formation 45.2 Impossible reactions
46 Lattice energies 46.1 What is meant by lattice energy? 46.2 The Born-Haber cycle 46.3 What do lattice energies teil us?
47 47.1 47.2 47.3 47.4
48 48.1 48.2 48.3
Enthalpy changes in Solutions Heats of neutralisation Hydration energies Heats of Solution Enthalpies of formation of ions in Solution
Internal energy What is internal energy? Taking account of work Measuring internal energy with a bomb calorimeter
49 Entropy 49.1 A first look at entropy
227 229 230
234
234 235
235 236 237 237 238 240
243 243 244 245
247 247 248 249 250
252 252 252 253
255 255 256
259 259 260
263 263 263 265
271 271 273 273
274
276 276 276
277
279 279
49.2 49.3 49.4 49.5 49.6 49.7
49.8 49.9 49.1( 49.1
50 50.1 50.2 50.3
50.4
50.5
51 51.1
51.2
51.3
52 52.1 52.2 52.3
52.4
52.5
52.6
53 53.1 53.2 53.3 53.4 53.5 53.6
53.7 53.8
54 54.1
54.2 54.3
55 55.1
The Boltzmann distribution 281 More about energy levels 281 Entropy changes and mixing of gases 282 Entropy and disorder 283 Reversible and irreversible changes 285 Some changes are spontaneous, some are not 285 Entropy and reversible changes 286 Entropy and non-reversible changes 286
49.10 Standard entropies 288 49.11 Calculating entropy changes 289
Free energy 291 What is free energy? 291 Standard free energies 293 Free energy values do not teil us how fast a reaction will occur 294 Free energy changes under non-standard conditions 294 Ellingham diagrams and the extraction of metals 295
Equilibrium and free energy 299 What is the effect of concentration and pressure on free energy? 299 What is the connection between free energy and equilibrium? 300 Equilibrium and equilibrium constants 301
Chemical equilibrium 304 Equilibrium constants 304 Equilibrium constants and their units 305 Are equilibrium constants really constant? 306 How does temperature affect an equilibrium reaction? 306 How can the connection between equilibrium constants and temperature be made more exact? 307 Pressure can change the proportions of reactants and products at equilibrium 308
Some equilibrium reactions 314 What this unit is about 314 The bismuth trichloride—water reaction 314 The chromate(vi)-dichromate(vi) reaction 314 The iodine—iodine trichloride reaction 314 The iodine—triiodide reaction 315 The nitrogen dioxide-dinitrogen tetraoxide reaction 315 The decomposition of ammonium salts 315 Reactions involving complex ions 315
Measuring equilibrium constants 318 How can equilibrium constants be measured? 318 The ester equilibrium 318 The hydrogen iodide equilibrium 320
Equilibria between phases 323 What is a phase? 323
vi Contents
55.2 How to interpret a phase diagram 55.3 The phase diagram of sulphur 55.4 The phase diagram of helium
56 Chromatography 56.1 What is chromatography? 56.2 Paper chromatography 56.3 Thin layer chromatography (TLC) 56.4 Column chromatography 56.5 Ion exchange chromatography 56.6 Gas-liquid chromatography (GLC) 56.7 High pressure liquid chromatography
(HPLC)
57 Polymorphism and allotropy 57.1 What is polymorphism? 57.2 What is allotropy?
58 Equilibrium between a solid and liquid
58.1 What happens when a liquid freezes? 58.2 Cooling curves 58.3 Cooling curves for mixtures
59 Solubility of salts in water 59.1 The solubility of a solid in water 59.2 Fractional crystallisation 59.3 Crystals that contain water of
crystallisation 59.4 Saturated and supersaturated Solutions
60 Explaining solubilities 60.1 Why is water a good solvent for ionic
crystals? 60.2 Entropy changes are important when a
crystal dissolves 60.3 The sizes of the ions in a crystal are
important in explaining solubilities 60.4 Why is water a good solvent for many
covalent substances? 60.5 Covalent liquids often dissolve covalent
solids 60.6 Volume changes when solids dissolve
61 Mixtures of liquids 61.1 What is the difference between miscible
and immiscible liquids? 61.2 Raoult's law and ideal Solutions 61.3 Solutions that do not obey Raoult's law 61.4 Why are there deviations from Raoult's
law? 61.5 Why do some liquids mix and others
not?
62 Competition between solvents 62.1 Solvent extraction 62.2 Solvent extraction is an equilibrium
process 62.3 Partition coefficients 62.4 Why do some results not fit the partition
law?
323 324 324
327 327 328 330 330 331 331
332
335 335 336
340 340 341 341
345 345 346
346 347
349
349
350
351
351
352 352
355
355 355 356
357
357
362 362
362 363
63 63.1 63.2 63.3 63.4 63.5
64 64.1 64.2
64.3 64.4
64.5
65 65.1 65.2
65.3 65.4
65.5 65.6 65.7 65.8 65.9
65.10 65.11 65.12
65.13
65.14
66 66.1
66.2 66.3 66.4 66.5 66.6 66.7 66.8 66.9 66.10
67 67.1
67.2
67.3 67.4
363
Distillation 365 The boiling points of mixtures 365 How distillation works 366 Industrial distillation 368 Does distillation always work? 369 Steam distillation 370
Solubility product 373 What is a solubility product? 373 Using solubility products to calculate solubilities 373 The common ion effect 375 Solubility products teil us when a precipitate will be made 375 Using solubility products in chemical analysis 376
Colligative properties 379 What are colligative properties? 379 Why does a solute influence the vapour pressure of water? 379 Elevation of boiling point 379 How to make use of the boiling point constant 380 Depression of freezing point 381 Osmotic pressure 382 Methods of measuring osmotic pressure 382 How might we explain osmosis? 383 How to calculate molar masses from osmotic pressure experiments 383 Some examples of osmosis 384 Abnormal molar masses 384 Calculating the degree of dissociation from abnormal molar masses 385 The thermodynamic explanation of colligative properties 386 Raoult's law and solids in Solution 387
Electrochemical cells 389 How an equilibrium is set up between a metal and Solution 389 The Standard hydrogen electrode 390 Standard electrode potentials 390 Combining half-cells 391 How to work out cell reactions 392 A quick way of writing cells 393 The anode and cathode in a cell 393 More about salt bridges 393 The electrochemical series 394 Some useful cells 395
Cells and concentration changes 400 How cell e.m.f.s change with concentration 400 How to work out equilibrium constants from cell e.m.f.s 401 Concentration cells 403 pH and the glass electrode 404
68 Corrosion 408 68.1 An example of corrosion 408
Contents vn
68.2 The rusting of iron 68.3 How does a layer of zinc prevent iron
rusting? 68.4 Why does tin protect iron from corrosion?
69 Cells and thermodynamics 69.1 The link between free energy and cell
e.m.f.s 69.2 Calculating Standard e.m.f.s from free
energy values 69.3 Calculating free energy values from
Standard e.m.f.s
70 Redox potentials 70.1 Standard redox potentials 70.2 Predicting redox reactions 70.3 Predicting reactions in the laboratory
from redox potentials 70.4 Redox titrations
71 Redox Charts 71.1 What is a redox chart? 71.2 How to use redox charts 71.3 What is disproportionation?
72 Electrolysis 72.1 What is an electric current? 72.2 What happens during electrolysis? 72.3 Examples of electrolysis 72.4 How to calculate the mass of a substance
liberated in electrolysis 72.5 Why is electrolysis used in industry?
73 Conductivity of Solutions 73.1 How do we measure conductivity? 73.2 Molar conductivities 73.3 Molar conductivities and the degree of
dissociation 73.4 How individual ions contribute to
conductivities 73.5 How can we make use of conductivity
measurements?
74 Acids and bases 74.1 Early ideas about acids 74.2 Acids give hydrogen ions in Solution 74.3 The Brensted theory of acids and bases 74.4 The Lewis theory of acids and bases
75 Strong and weak acids 75.1 What is the difference between strong
and weak acids? 75.2 Conjugate acids and bases 75.3 The ionic produet of water 75.4 Acid dissociation equilibrium constants 75.5 What makes an acid strong? 75.6 What is the connection between pH and
PKa? 75.7 Base dissociation constants and p/Cb
75.8 How to work out the degree of dissociation of a weak acid
409 75.9 How to work out the pH of a weak acid 450 75.10 Buffer Solutions 450
Neutralisation and titrations 455 Salt hydrolysis 455 Salts of a strong acid and a strong base 455 Salts of a strong acid and a weak base 455 Salts of a weak acid and a strong base 455 Salts of a weak acid and a weak base 456 Endpoints in titrations depend on the strength of the acid and base 456 Indicators 456
Rates of reactions 459 Why do we study the rates of reactions? 459 What makes reactions take place? 459 What can prevent reactions taking place? 460 How can we make reactions go faster? 461
Two theories of reaction rates 465 Collision theory 465 More about the activation energy 466 Catalysts and activation energy 467 Transition State theory 467
Measuring the rates of reactions 471 An example of measuring a rate 471 Six ways of measuring rates 472 Measuring the rates of very fast reactions 476
Rate laws 480 What is a rate law? 480 How can we discover the rate law? 481 Quick ways of finding the rate law 482 The contribution of individual Orders to the overall rate law 484
Reaction mechanisms 487 What is a reaction mechanism? 487 Bonds can break in two ways 487 The slowest Step in a reaction governs the rate 488 Free radical reactions 489 Mechanisms of the hydrolysis of halogenoalkanes 490 The influence of catalysts 491 The kinetics of enzyme reactions 492
I N D U S T R I A L CHEMISTRY
The chemical industry 497 Why is the chemical industry important? 497 The stages in producing a new produet 498 The economics of produetion 499 Cash flow in the produetion cycle 500 Running a chemical plant 501 Designing a chemical plant 502 Energy and mass balances 502
82.8 Continuous and batch processing 503
409 410
412
412
412
413
415 415 416
416 417
420 420 420 422
426 426 427 428
430 431
433 433 434
435
435
436
439 439 439 440 441
76 76.1 76.2 76.3 76.4 76.5 76.6
76.7
77 77.1 77.2 77.3 77.4
78 78.1 78.2 78.3 78.4
79 79.1 79.2 79.3
80 80.1 80.2 80.3 80.4
81 81.1 81.2 81.3
81.4 81.5
81.6 81.7
443
443 443 444 445 446
448 449
82 82.1 82.2 82.3 82.4 82.5 82.6 82.7
449
vm Contents
83 83.1
83.2 83.3
83.4
Chemical processes Examples of modern chemical manufacture Manufacture of sulphuric acid The Haber process for the manufacture of ammonia The manufacture of nitric acid
506
506 506
508 510
84 The chlor-alkali industry 512 84.1 What is the chlor-alkali industry? 512 84.2 The production of chlorine and sodium
hydroxide 512 84.3 The ammonia-soda (Solvay) process 514
85 The extraction of metals 518 85.1 The methods of extraction 518 85.2 Extracting the noble metals 518 85.3 Reducing sulphide ores 520
85.4 Reducing an oxide ore 85.5 The extraction of reactive metals
86 The oil industry 86.1 Why is the oil industry important? 86.2 Catalytic re-forming 86.3 Catalytic cracking 86.4 Thermal cracking
Appendix A The laws of thermodynamics Appendix B Table of ionisation energies Appendix C Table of atomic masses Appendix D Values of some universal
constants Bibliography Examination questions Answers to examination questions Subject index Index of names
520 521
525 525 526 527 528
533 535 536
538 539 540 558 559 569