School of Chemistry Data and Formulae Booklet Not To Be Removed From The Examination Room School of Chemistry University of Leeds 2010. Index Binomial series & Expansion ………... 29 Character Tables ……………………... 22 Angular Parts of Atomic Orbitals .. 12 Mulliken Labels ………………… Point Groups and their Symmetry Operations ………………………. Road Map for Systematically Determining a Point Group ……... Chemical Kinetics …………………… 22 Atomic Term Symbols …………. 13 Commutators and the Uncertainty Principle ………………………… 9 Chromatography and Electrophoresis .. 23 Quantum Mechanics …………………. 9 Free Translational Motion ……… 10 Harmonic Oscillator ……………. 11 21 Hydrogen Atom ………………… 12 Classical Mechanics …………………. Conversion Table: Energy Units and Related Quantities …………………… Covalent Bond Lengths (table) ……… 8 Operators ……………………….. 9 Particle in a Box ………………... 10 11 Electrochemistry …………………….. 20 Enthalpy and Entropy of Fusion and Vaporisation at Phase Transitions (Table) ……………………………….. Rigid Rotor ……………………... Schrödinger Equation and Wavefunctions ………………….. Spherical Harmonics …………… 56 Gas Kinetic Theory ………………….. 8 Redox Potentials at 298 K, vs. Hydrogen Potential …………………... Greek Alphabet ……………………… 4 SI Derived Units with Special Names and Symbols …………………………. 1-2 Intermolecular Forces ………………… 15 Common non-SI units …………... 2 MAPLE ……………………………… 32 Solution Equilibria …………………... 19 Mass Spectrometry …………………... 21 Spectrophotometry and Fluorimetry … 13 Mathematical Formulae ……………... 27 Statistics ……………………………... 25 Propagation of Errors …………... 26 24 14 4 5 9 12 Tunnelling Through a Barrier …... 10 7 Mathematical Symbols ………………. 31 Molecular Constants for selected Diatomic Molecules (Table) ………… 5 NMR …………………………………. 13 Periodic Table & Atomic Properties of the Elements …………………………. 16-17 Phase Equilibria ……………………... 20 Thermodynamic Quantities (table) ….. Thermodynamics and Statistical Mechanics …………………………… Waves ………………………………... Physical Constants …………………... 3 X-ray Crystallography ……………….. 15 Prefixes ………………………………. 4 Student’s t distribution table ……. 26 6 18 8 Names and Symbols for SI base units Physical quantity Length symbol l (lower case L) base SI unit metre m kg Mass m kilogram Time t second s Temperature T kelvin K Amount of substance Electric current n mole mol I ampere A Luminous intensity Iv candela cd SI derived Units for other Quantities Physical quantity Common symbol Expression in base units Volume V m3 Molar volume Vm m3 mol–1 Speed, velocity s, v m s–1 Angular velocity s–1, rad s–1 Wavenumber v m–1 Acceleration a m s–2 Momentum p kg m s–1 (mass × velocity) Energy E 2 –2 kg m s (mass × velocity2) Force F kg m s–2 Density kg m Pressure P N m–2 = kg m–1 s–2 Surface tension N m = kg s Viscosity Pa s = kg m–1s–1 (pressure × time) Heat capacity Entropy C P, C V S (used as cm–1) –1 (mass/volume) –2 (force/area) (force/ length) J K–1 = kg m2 s–2 K–1 J K–1 C P, C V J K–1 mol–1 Molar entropy S J K–1 mol–1 Molar energy A, G, H Molar heat capacity (mass × acceleration) –3 J mol–1 = kg m2 s–2 mol–1 1 SI Derived Units with Special Names and Symbols Name of SI unit Physical quantity Symbol for SI unit Expression in terms of SI base units hertz Hz s–1 force newton N m kg s–2 pressure, stress pascal Pa N m–2 = m–1 kg s–2 energy, work, heat joule J Nm = m2 kg s–2 power, radiant flux watt W J s–1 = m2 kg s–3 coulomb C As electric potential, electromotive force volt V J C–1 electric resistance ohm V A–1 = m2 kg s–3 A–2 electric conductance siemen S –1 electric capacitance farad F C V–1 = m–2 kg–1 s4 A2 magnetic flux density tesla T V s m–2 = kg s–2 A–1 magnetic flux weber Wb inductance henry H frequency electric charge Vs = m2 kg s–3 A–1 = m–2 kg–1 s3 A2 = m2 kg s–2 A–1 V A–1 s = m2 kg s–2 A–2 Common non–SI units Angstrom (Å) litre (L, l) = 10 –10 = 1 dm m 3 3 1 cm3 (cc) = 1 mL tonne = 10 kg Atmosphere (atm) = 101.325 kPa bar = 105 Pa 1 atm = 760 torr Electron Volt (eV) = 1.60218 ×10–19 J Centipoise (cP) = 10–3 Pa s mm Hg calorie = 1 torr = 4.184 J The following units are deprecated dyne (dyn) = 10–5 N erg = 10–7 J Gauss = 104 T (tesla) 2 Selected Physical Constants Speed of light in vacuum c 2.99792458 108 m s–1 (defined value) Permeability of vacuum 0 (410–7) =1.256637 10–6 H m–1 Permittivity of vacuum 1/(0c2) 0 8.854188 10–12 F m–1 Faraday constant F 9.64853 104 C mol–1 Avogadro constant NA 6.02214 1023 mol–1 Unified atomic mass unit u 1.66054 10–27 kg Boltzmann constant kB 1.38065 10–23 J K–1 Gas constant R 8.31447 J mol–1 K–1 Elementary charge e 1.60218 10–19 C Mass of electron me 9.10938 10–31 kg Mass of proton mp 1.67262 10–27 kg Mass of neutron mn 1.67493 10–27 kg Mass of hydrogen atom mH 1.67343 10–27 kg Proton–electron mass ratio mp/me 1836.15 Fine structure constant e2/(20c) 7.2973510–3 (≈1/137) Rydberg constant 2me2/(2h) R 1.09737 107 m–1 R 13.6057 eV RH 1.09678 107 m–1 h 6.62607 10–34 J s 1.054572 10–34 J s a0 5.29177 10–11 m Hartree energy 2R∞hc Eh 27.2114 eV Proton Magnetogyric ratio p 26.7522107 rad T–1 s–1 for hydrogen Planck constant Bohr radius /(4R∞) 3 Conversion Table: Energy Units and Related Quantities J J kJ mol–1 eV Hz cm–1 1 6.0221020 6.2411018 1.5091033 5.0341022 1 1.03610–2 2.5061012 83.59 96.48 1 2.4181014 8.065103 1 3.33610–11 2.9981010 1 kJ mol–1 1.66110–21 eV 1.60210–19 Hz 6.62610–34 3.99010–13 4.13610–15 cm–1 1.98610–23 1.19610–2 1.24010–4 To convert 6 eV into cm–1, read along from eV in the left column and multiply by the number under cm–1 in the top row, e.g. 6 eV= 6 8.065 103 cm–1/1 eV= 4.839104 cm–1 To convert kBT into cm–1 at T = 300 K 1.38110–23 J/K 300 K = (1.38110–23 300) J 5.0341022 cm–1/1J = 208.5 cm–1 Greek Alphabet Normal text a b g d e z h q i k l m alpha beta gamma delta epsilon zeta eta theta iota kappa lambda mu Normal text n x nu xi omicron pi rho sigma tau upsilon phi chi psi omega o p r s t u f c y w Prefixes z a f p n m c d k M G T P E Z zepto atto femto pico nano micro milli centi deci kilo mega giga tera peta exa zeta –6 –3 –2 –1 3 6 9 12 15 18 1021 10 –21 10 –18 10 –15 10 –12 10 –9 10 10 10 10 10 10 10 10 10 10 4 Molecular Constants for selected Diatomic Molecules v /cm–1 re /pm Be /cm–1 H2 4401 74.14 60.853 432 D2 3115 74.15 30.444 439 HCl 2991 127.5 10.5934 432 OH 2720.9 96.99 10.01 423 HBr 2649 141.4 8.4649 366 N2 2358.6 109.8 1.99824 945 HI 2309 160.92 6.4264 298 CO 2170 112.8 1.9313 1080 NO 1904.03 115.08 1.7046 510 O2 1580 120.8 1.44563 498 PbH 1564.1 183.9 4.971 153 S2 725.68 188.9 0.2956 424 Cl2 559.7 198.8 0.244 243 I2 214.5 266.6 0.03737 151 Na2 159.2 307 0.1547 70.4 35 D0 /kJ mol–1 Data from Engel & Reid, Physical Chemistry & Herzberg, Spectra of Diatomic Molecules. Covalent Bond Lengths bond r /pm bond r /pm H–H 74 N–N 146 C–C 154 N=N 120 C=C 134 N≡N 110 C≡C 120 C–Cl 177 C=C (aromatic) 139 C–N 147 C–O 143 C=N 127 C=O 122 C≡N 116 C–H 110 C–S 182 5 Tables of Thermodynamic Quantities o Standard Enthalpies of Formation f H at 1 bar and 298 K unless otherwise stated, Enthalpies o of Combustion c H and Heat Capacities CP (at 298 K) Name f H o / formula kJ mole –1 c H o / kJ mole –1 CP / J K–1 mol–1 Ammonia (g) NH3 –46.11 - 35.62 Benzene (liq) C6H6 49.0 –3268 82.34 Ethane (g) C2H6 –84.7 –1560 52.38 Ethanol (liq) C2H5OH –277.6 –1368 112.3 Fluorine (liq) F2 –13.1 at 85.02 K - 31.30 (gas) C6H12O6 –1274 –2808 219.2 Hydrazine (g) N2H4 50.6 - 49.6 Hydrogen (liq) H2 –9.02 at 20.27 K –286 28.84 (gas) H2O2 (liq) –187.9 - 43.1 Methane (g) CH4 –74.81 –890 35.7 Methanol (l) CH3OH –238.7 –721 81.1 Nitrogen dioxide (g) NO2 33.18 - 37.18 Nitrogen tetroxide (g) N2O4 9.16 - 79.2 Oxygen (liq) O2 12.99 at 90.18 K - 29.38 (gas) Octane (liq) C8H8 –249.9 –5471 254.7 O3 142.7 - 39.2 NaCl –411.2 - 50.5 Sucrose (s) C12H22O11 -2222 –5645 427.6 Water (liq) H2O –285.8 - 36.2 Glucose (s) Hydrogen peroxide Ozone (g) Salt (s) Standard Enthalpy and Entropy of Fusion and Vaporisation at Phase Transitions Tf /K fus H o / fus S o / kJ mole–1 J K–1mole–1 Tb /K vap H o / vap S o / kJ mole–1 J K–1mole–1 Ar 83.81 1.188 14.17 87.29 6.506 74.53 C6H6 278.61 10.59 38.00 353.2 30.8 87.19 H2O 273.15 6.008 22.00 373.15 40.656 109.0 He 3.5 0.021 4.8 4.22 0.084 19.9 (at 8 K & 30 bar) Data from Atkins & De Paula, Physical Chemistry & Engel & Reid, Physical Chemistry 6 Standard Redox Potentials at 298 K, vs. Hydrogen Potential Couple or reduction half reaction F2 +2e 2F O3 +2H+ +2e O2 +H2O +2.076 Cl2 (g)+2e 2Cl +1.3595 O2 +4H+ +4e 2H2O +1.229 Cl2 (aq)+2e 2Cl +0.954 Hg 2 2e Hg +0.851 Ag + +e Ag Q 2H 2e QH2 +0.7996 +0.699 Cu e Cu O2 +2H2O+4e 4OH 3 Strong oxidant † +0.521 +0.401 Fe CN 6 e Fe CN 6 4 +0.358 Cu 2+ +2e Cu Hg2Cl2 +2e 2Hg(l )+2Cl +0.342 +0.2412 in sat. KCl (SCE * ) Ag + +e Ag (as Ag/AgCl electrode) +0.225 in 1 mol/kg KCl 0 defined as zero 2H+ +2e H2 NAD H 2e NADH Pb2 2e Pb CO2 2H 2e HCO2 H # –0.105 –0.126 –0.20 Cd2+ +2e Cd Zn 2+ +2e Zn PO34 2H2O 2e HPO32 3OH –0.403 –0.763 –1.05 V2+ +2e V Al3+ +3e Al Mg 2+ +2e Mg –1.175 –1.662 –2.372 Na + +e Na Li+ +e Li –2.714 –3.040 † Q = 1, 4-benzoquinone, QH2 dihydroquinone # E o (V) +2.866 (–0.320, pH 7) (–0.42, pH 7) Strong reductant * Saturated Calomel Electrode NAD+ is nicotinamide adenine dinucleotide 7 Gas Kinetic Theory Molar volume and concentration Vm V / n , c n / V Compression factor Z Ideal gas equation of state PV nRT Distribution of molecular speeds 4 M f s 2 RT Root mean square speed 3RT c M Mean speed 8 RT c M PV PVm nRT RT 3/2 crel Collision frequency z Mean free path 3k T B m 1/2 8k T B m 8 RT 2 cPN A , RT c z Ms 2 / 2 RT 1/2 1/2 1/2 1/2 Mean relative speed s2 e , m1m2 m1 m2 d2 (for identical molecules) RT k T V B 2 PN A 2 P 2 N A Collision rate of gases on surfaces (per m2) Z P 2 mk BT 1/2 Classical Mechanics Velocity v dx / dt Acceleration a dv / dt d 2 x / dt 2 Momentum p mv Force F ma dp / dt dVdx Kinetic energy K p2 1 2 mv 2m 2 Total Energy E K V Waves Electromagnetic waves v c / Frequency s–1 Angular frequency rad s–1 and 2 Other waves v v / . Frequency in wavenumbers 1/ cm–1 or rad cm–1 Period 1/ sec or 2 / sec Wavevector k 2 / 8 Quantum Mechanics Photon Energy E h de Broglie relation Bohr condition E h hc hcv h p Operators d dx Position xˆ x Momentum pˆ i Kinetic energy 2 d 2 Kˆ 2m dx 2 Potential energy Vˆ V x Hamiltonian Hˆ Kˆ Vˆ Commutators and the Uncertainty Principle Operators  and B̂ then ˆ ˆ BA ˆˆ . Aˆ , Bˆ AB Standard deviation of operator  Aˆ Aˆ 2 Aˆ Uncertainty principle (general) Aˆ Bˆ 1 ˆ ˆ A, B 2 Uncertainty Principle (position – momentum) xpx 2 ‘Time–energy uncertainty’ relation E t 2 2 Angular momentum components lˆx , lˆy ilˆz , lˆz , lˆx ilˆy , lˆy , lˆz ilˆx Schrödinger Equation and Wavefunctions Time dependent (TD) Schrödinger eqn. x, t Hˆ x, t i t Time independent (TI) Schrödinger eqn. Ĥ x E x Total wavefunction of TI systems x, t eiEt / x Wavefunction normalisation N x x dx Alternatively N 2 x dx Normalised if x x dx 1 2 9 Wavefunction orthogonality (x) and (x) x x dx 0 Overlap between wavefunctions (x) and (x) S x x dx A x Aˆ x dx Expectation value of any operator  Probability density x x Probability Px0 x1 x dx 2 x1 x0 Free Translational Motion Potential energy V x 0 Ek Total energy 2 2 k (mass m quantum number k) 2m Wavefunction k Aeikx Beikx A B C cos kx D sin kx Particle in a Box of length L 2 n Total Energy En 2m L Potential energy V x 0 Wavefunction n x Quantum numbers n = 1, 2, 3, 4, … 2 joule 2 n x sin L L Number of nodes N n 1 Tunnelling Through a Square Barrier Potential energy 0 if x 0 V V0 if 0 x L 0 if x L Wavefunctions A1eik1x B1eik1x if x 0 V k 2 / 2m if E V 0 2 0 Energy E 2 V0 2 / 2m if E V0 A3eik3x if x L A2eik2 x B2eik2 x if 0 x L and E V0 A2ei2 x B2ei2 x if 0 x L and E V0 k 2mE 2 Reflection coefficient R B1 / A1 2 2m V E 2 transmission coefficient T 1 R A3 / A1 2 10 Harmonic Oscillator Potential energy 1 V x kx2 2 Frequency Total energy 1 Ev v hv joules 2 Quantum number v = 0, 1, 2, 3… Wavefunction v N v H v y e y Normalisation N v 2 v v! k rad s–1 or v 1 2 k –1 s or /2 1/2 1 2 c Reduced mass Number of nodes 2 v k cm–1 mA mB mA mB N v where y x / and / k 1/4 . (v is quantum number, v frequency) Hermite polynomials H0 y 1 H1 y 2 y H 3 y 8 y3 12 y H 4 y 16 y 4 48 y 2 12 H 5 y 32 y 5 160 y3 120 y H 6 y 64 y 6 480 y 4 720 y 2 120 H2 y 4 y2 2 Rigid Rotor Energy EJ 2 J J 1 joules 2I Angular momentum quantum number Degeneracy J = 0, 1, 2, 3 … Magnetic (Azimuthal or projection) quantum number Rotational constant B gJ 2J 1 mz 0, 1, 2, J 2 joules or B cm–1 where h / 2 2I 4 cI Moment of inertia I r 2 kg m2 Magnitude of angular momentum J J J 1 Magnitude of z component J z mz Wavefunction j ,mz , Y jmz , 11 Hydrogen Atom VeN r Potential energy Principal quantum number En Total energy hcRH n 2 1 e 4 0 r [ Hydrogenic Atom VeN r n = 1, 2, 3… joules gn n 2 Degeneracy 1 1 E hcRH 2 2 where n1 < n2 n1 n 2 Transition energy Orbital angular momentum quantum number l 0, 1, 2, , n 1 Magnetic (Azimuthal or projection) quantum number ml 0, 1, 2, , l Number of nodes of radial wavefunction R is N n l 1 Hamiltonian Hˆ Kˆ r Vˆr Kˆ , Wavefunction n,l ,ml r, , Rn,l r Ylml , 1 Z 2e ] 4 0 r Spherical Harmonics Ylm , l Y00 , 1/ 4 Y10 , 3 4 cos Y11 , 5 Y2 , 3 8 sin e i 15 i 3 cos 2 1 Y21 , sin cos e 16 8 0 2 Y2 , 5 16 sin 2 e 2i Angular Parts of Atomic Orbitals s Y00 px d Y 2 1 Y2 0 z 2 1 1 1 Y1 Y 2 py i d xz 1 d x y 2 1 1 Y 2 2 1 2 Y1 1 pz Y1 d yz i d xy i 1 Y2 Y 2 1 2 2 0 2 Y2 Y 2 1 2 Y2 Y 2 2 2 Y2 1 2 12 Atomic Term Symbols 2S 1 LJ L = S, P, D, F, G, H, I symbols represent numbers calculated using L l1 l2 , l1 l2 1 l1 l2 and where S s1 s2 , s1 s2 1 s1 s2 and J L S , L S 1 L S Spectrophotometry and Fluorimetry [c] l [c] l Beer’s Law may either be defined as Itrans I 0e or as Itrans I010 I A log10 trans c l Transmittance T I trans / I 0 I0 kx rate of production of x Quantum yield of x x rate of absorption sum of all k ' s Absorbance If0 Stern-Volmer equations I fQ 1 0kQ Q 1 1 kQ Q Q 0 NMR Nucleus 12 C H 13 C 15 N 19 F 29 Si 31 P 103 Rh 195 Pt 2 H 14 N 11 B 23 Na 35 Cl 37 Cl 17 O 27 Al 10 B 1 Spin quantum number I Magnetogyric ratio, / 107 rad T–1 s–1 Natural Abundance % 0 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1 1 3/2 3/2 3/2 3/2 5/2 5/2 3 0 +26.75 +6.73 –2.712 +25.18 –5.32 +11.32 –0.847 +5.84 +4.11 +1.934 +8.58 +7.08 +2.62 +2.18 –3.63 +6.97 +2.87 98.9 99.98 1.1 0.37 100.0 4.70 100.0 100.0 33.8 0.02 99.63 80.4 100.0 75.77 24.23 0.037 100.0 19.6 13 Spin quantum numbers { I, mz }, where I = 0, 1/2, 1, 3/2 …. mz 0, 1, 2, I Degeneracy g 2I 1 Energy in field B E μ B and in z direction E z B0 mz B0 joule Magnetic dipole moment z mz joule/Tesla Magnitude of spin angular momentum Iˆ I I 1 J s rad–1 z-component of spin angular momentum I z mz J s rad–1 Transition energy Chemical shift Magnetisation E B0 joule Frequency v v vref 106 ppm vref n n M0 N z evaluates to n n Magnetisation on z-axis (longitudinal component) dM z M 0 M z / T1 dt B0 –1 s or B0 rad s–1 2 M 0 Nmz 22 B0 2 k BT M z M 0 M z 0 M 0 e t /T 1 M z M 0 1 2et /T1 if M z 0 M z (t 0) M 0 Chemical Exchange T G 19.134 103 Tc 10.32 log10 c kJ mol–1 where k v / 2 s–1 k then Chemical Kinetics First order reaction k A P k Second order reaction A A P Half–life of a first order reaction At A0 exp kt 1 1 = kt [ A]t [ A]0 t1/2 ln 2 / k sec Half–life of a second order reaction (A + A) t1/2 1 sec k [A]0 E k A exp a RT E k d 2 v exp a m3s–1 Collision Theory RT S ‡ H ‡ –1 k BT Thermodynamic formulation of TST k= exp exp s h R RT k 4000 rD dm3 s–1 where D kBT / 4r m2 s–1 Diffusion limited rate coefficient Pressure dependence of activation controlled reaction in solution: ln k / P T V ‡ / RT Arrhenius Equation 14 Intermolecular Forces Charge–Charge (Coulomb) energy 1 q1q2 4 0 r Charge–Dipole energy (at angle ) Dipole–Dipole energy μ1r μ1 r 1 μ1 μ2 3 3 (1, 2 and r are vectors) 4 0 r r5 Freely rotating dipoles (Keesom Energy) Dipole–non–polar molecule 1 q cos 4 0 r2 12 22 4 0 2 k BT 3r 6 1 2 1 3cos 2 1 4 0 2 2r 6 (dipole at angle ) 12 6 4 r r Lennard–Jones 6–12 potential VLJ Van der Waals equation of state an 2 P 2 V nb nRT V Virial equation of state B T C T PVm 1 RT Vm Vm2 X-ray Crystallography Structure factor Fhkl f j e i hkl j where hkl j 2 hx j ky j lz j j Fourier synthesis of electron density r 1 2 i hx ky lz Fhkl e V hkl 1 2 2 i hx ky lz Fhkl e V hkl Patterson synthesis Pr Bragg’s law n 2dhkl sin Orthorhombic lattice 1 h2 k 2 l 2 2 2 2 2 d hkl a b c 15 16 17 Thermodynamics and Statistical Mechanics ni gi ( i 0 )/ kBT ni gi ei / kBT e also n0 g 0 N q Boltzmann equation Molecular partition function is Sum over States of energy levels j q g je (energy is j, degeneracy gj) j / k BT j Factorisation qtot qtrans qrot qvib qelec qext qint Distinguishable particles Q qN Indistinguishable particles qN Q N! First Law of Thermodynamics dU dq dw Enthalpy H U PV Heat Capacity dq C dT For pure materials dU CV dT V dH CP dT P For reactions d U CV dT V d H C P dT P Second Law of Thermodynamics dS U q w _ dq T S kB ln W Combined First and Second Laws dU TdS PdV dH TdS VdP closed systems Helmholtz energy A U TS dA PdV SdT closed systems Gibbs energy G H TS dG VdP SdT closed systems G T , P nFErev Chemical potential dG i dni T , P ,n j For pure substances G . n For pure solids and liquids O 18 Pure ideal gas P O RT ln O , P O 105 Pa (1 bar) P Gas mixtures p i i O RT ln Oi P i xi , x O 1 O x Liquid mixtures and solvents i iO RT ln ai , ai Solutes Equilibrium For the reaction i i O RT ln ai , ai i mi , m O 1 mol kg -1 O m I IO RT ln ai , ai i ci , c O 1 mol dm-3 O c i dni 0 vi i 0 A g B g C g K p p C A / po / po p B / po G O RT ln K ln K r H O RT 2 T P ln K 2 ln K1 Raoult’s law pi P O xi Henry's law pi ki xi r H O R 1 1 T2 T1 Solution Equilibria Equilibrium and free energy K exp G O / RT Definition of pH pH log10 H Acid dissociation constant Ka pH and pKa [A ] pK a pH log10 [HA] Basicity constant [BH ][OH ] Kb [B] pH and pKb pK b 14 pK a [H ][A ] [HA] 19 [B] pKa pH log10 [BH ] K a1 K a2 F K a1 KW Isoionic point [H ] Isoelectric point pH pK a1 pK a2 / 2 K a1 F Electrochemistry Nernst equation for a half-cell Solution redox equilibria mOx ne rRed E Eo RT [Red] r ln nF [Ox] m , E Eo [Red] r 0.05916 log10 m n [Ox] at 25 C E E E 0.05916 log10 Q n G nF E E E o at 25 C 0 0 G Edonor Eacceptor Electrochemical cells Replace E with Ecell in redox equilibrium formulae. Phase Equilibria Adsorption equilibria Kads,A Vaporisation equilibria K vap,A nb,A [A]M nempty Cation–exchange equilibria Kexch Partition coefficient Kp,A Distribution ratio DA pA S,A A or nb,A pM,A nempty pA [M ]res [H ]sol [M ]sol [H ]res [A]org [A]aq [A in all of its forms]org [A in all of its forms]aq 20 Solvent extraction nex D ni Vaq D V org Chromatography and Electrophoresis tr tm V D s tm Vm Chromatographic capacity factor k Retention volume Vr VM DVs Chromatographic resolution R 2 t R1 t R2 N 1 k or R 4 1 k wb1 wb2 Gas chromatography k A RT S Vs S , A pA M S VM Electrophoretic mobility e q 6 r Retention factor Rf Separation factor Migration in capillary electrophoresis u (e eo ) or R tm tr k2 k1 t R wb2 E L Mass Spectrometry Relative intensity of M+1 isotope peak I M 1 100% nH 0.012 nC 1.07 ... IM Exact Masses of Isotopes and their Natural Abundance Element H C N O Cl Fe Mass number Mass / Da Abundance / % 1 2 12 13 14 15 16 17 18 35 37 54 56 57 1.00783 2.01410 12 (exact) 13.00335 14.00307 15.00011 15.99491 16.99913 17.99916 34.96885 36.96590 53.93961 55.93494 56.93540 99.988 0.012 98.93 1.07 99.632 0.368 99.757 0.038 0.205 75.78 24.22 5.845 91.754 2.119 21 58 57.93328 0.282 Understanding Character Tables Symmetry operations. In C3v there are a total of h = 6 operations Class C3 Point Group name Number of operations in class v C3v E 2C3 3v A1 1 1 1 z A2 1 1 -1 Rz E 2 -1 0 (x, y), (Rx, Ry) Mulliken labels are shorthand for Character representations of molecular, orbital & vibrational Irreducible symmetry species. representation A2 in point group C3v. (+1 if operation symmetric, –1 if not) x2+y2, z2 (x2-y2, xy), (xz, yz) Product transformations. x2+y2 represent s orbitals, the others, d orbitals. All are operators for Raman spectroscopy selection rules Linear transformations. x, y, z operators used in transition dipole selection rules. Rotation operators Rx, Ry, Rz used in spin orbit coupling and whole body rotation about axis shown. Brackets indicate degeneracy Mulliken Labels (Principal Axis is labelled as Cn) A B E T subscript 1 subscript 2 g u superscript ' superscript '' singly degenerate, symmetric about Cn axis (+1 in table) singly degenerate, anti-symmetric about Cn axis (–1 in table) double degenerate triply degenerate symmetric about C2 axis to Cn axis or v if no C2 present, e.g. A1 anti-symmetric about C2 axis to Cn axis or v if no C2 present, e.g. A2 ‘gerade’, symmetric to inversion i , e.g. E2g ‘ungerade’, anti- symmetric to inversion i, e.g. B2u symmetric to h, e.g. A' anti-symmetric to h, e.g. E'' 22 Point Groups and their Symmetry Operations (excluding the identity E). Cn 360/n fold rotation; n = 2 180; n = 3 120; n = 4 90 rotation. i = inversion; h = horizontal mirror plane, v = vertical mirror, d = dihedral mirror plane. Sn = rotation-reflection. Angle is 360/n Cn2 means Cn applied twice over and Sn5 means Sn applied 5 times etc. ( note Cnn = E, S2 = i, S2nn = Cn ) Point group C1 Cs Ci C2 C3 C2 C3 Symmetry Operations C4,5,6 i v h d Sn all the rest E identity only h i C2 C32 C3 C2v C3v C4v C2 C2h C3h D2 D3 C2 3C2 3C2 D2h D3h D4h D5h D6h 3C2 3C2 C2 5C2 C2 v, v' 3v 2v 2C3 C2 2C4 2d h h i C3 S3 C32, S35 C2 C2(x),C2(y)C2(z) 2C3 i 2C3 2C3 2C4 5C5 2C6 i i 2v 3v 2v 5v 3v h h h h h (xy),(xz),(yz) 2d 3d 2S3 2S4 2S5 2S6 2C2' , 2C2'' 2C52 2S3, 3C2', 3C2'' C2 2S4 C2 ' D2d 2d 3C2 2C3 i 2S6 D3d 3d C2 2C4 2S8 4C2' , 2S83 D4d 4d 5C2 2C5 i 2S10 2C52, 2S103 D5d 5d C2 S4 S43 S4 3C2 8C3 6S4 Td 6d 6 6C2 8C3 6C4 i 6S4 8S6 , 3C2 Oh 3h d Identify Dh (e.g. homonuclear diatomic) and Cv (e.g. heteronuclear diatomic) directly by their shape. 23 ‘Road Map’ for Systematically Determining a Point Group Special groups? No h No i C1 i Ci No Cn axis No h i Cs C∞v D∞h Td Oh Ih Yes Cn axis n-C2’s perp to Cn axis No n-C2’s perp to Cn axis Cnh Cnv S2n h Dnh h No h n-v No h n-d No v S2 × n No S2 × n Cn Dnd Nod Dn 24 Statistics Mean x Sample standard deviation s Gaussian probability distribution Confidence interval Student's t–test, case 1 1 n xi n i 1 1 n xi x 2 n 1 i 1 x 2 p( x) exp 2 2 2 2 ts x n x k tcalc n tcrit s 1 s 2 n 1 s2 2 n2 1 n1n2 with s pooled 1 1 n1 n2 n1 n2 2 x1 x2 t–test, case 2a tcalc t–test, case 2b tcalc with s 2 n1 n2 s pooled x1 x2 s12 n1 s22 n2 s12 2 d sd 2 s2 n 2 s2 2 n2 1 1 n 1 n 1 2 1 t–test, case 3 tcalc Calibration by standard addition I S X [ X ] f [S ] f IX [X ] i 2 sd n with 1 2 degrees of freedom di d 2 i n 1 V V I I S X total I X X [S ]i S [X ] i V0 V0 sX sy m D2 Calibration with an internal standard [X ] F n n i 1 i 1 X 2 n xi 2 2 X xi IX [S ] IS 25 Student’s t–distribution table Two tailed confidence 90% 0.05 /2 v = n –1 1 2 3 4 5 6 7 8 9 10 15 20 30 40 50 95% 99% 0.025 0.005 6.314 2.920 2.353 2.132 2.015 1.943 1.895 1.860 1.833 1.812 1.753 1.725 1.697 1.684 1.676 (Normal distribution) 1.645 12.71 4.303 3.182 2.776 2.571 2.447 2.365 2.306 2.262 2.228 2.131 2.086 2.042 2.021 2.009 1.960 63.66 9.925 5.841 4.604 4.032 3.707 3.499 3.355 3.250 3.169 2.947 2.845 2.750 2.704 2.678 2.576 Propagation of Errors 2 If y f u, v , the variance squared is y2 2 y y u2 v2 u v v u y2 f(u, v) u v, u v u2 v2 uv v2 u2 u 2 v2 u/v v 2 u2 u 2 v2 v4 1 1 , u v 1 1 u v v 4 u2 u 4 v2 u 4v 4 a 2 v2e2av eav uev u ln v 2 u u 2 v2 e2v v 2 u2 u 2 v2 v 2 ln v 2 26 Useful Mathematical Formulae Equation of straight line y mx c with gradient m intercept c y y Given points (x1, y1) and (x2, y2) then y 2 1 x x1 y2 x2 x1 a b2 a2 2ab b2 1 x b a x b a b a b a 2 b2 a xa x a b b x xa xb xab ax2 bx c 0 with solution (roots) r x! x x 1 x 21 n x x1/n b b 2 4ac 2a 0! 1 x n 1 x 2 x3 x 4 n 0 Absolute value x x log log x log y y log xy log x log y log x a a log x log x means take log to power a: log xa log x logk x logk m logm x , loge x loge 10 log10 x 2.3026 log10 x a a ln x loge x sin opposite hypotenuse cos Arithmetic mean a b / 2 adjacent hypotenuse tan opposite adjacent Geometric mean ab sin all tan cos Harmonic mean Probability = number of desired outcomes /total number of possible outcomes 2ab a b p n/k Number of Combinations: order does not matter. select k items out of n; Number of Permutations: order does matter Cnk n n! k ! n k ! k Pnk n! n k ! Pnk Cnk 27 Differentials and Integrals (c is an arbitrary constant) ax n1 c n 1 d n ax nax n1 dx n ax dx d 1 ln x dx x d ax e aeax dx ax ax ae dx e c dx ln x c x d sin x cos x dx sin x dx cos x c d cos x sin x dx cos x dx sin x c d tan x 1 tan 2 x dx tan x dx ln cos x c d dv du (uv) u v dx dx dx udv v vdu (by parts) dy dy dz (chain rule) dx dz dx dx 1dx x c Substitution. Let u be a function of x, e.g. u x2 dx then f x dx f u du du dy dx 1/ dx dy Trigonometric Functions In a right angled triangle, x horizontal, y vertical, hypotenuse r then, sin y r r x2 y 2 cos x r tan sin cos y x sin 2 cos 2 1 ei cos i sin sin 2 2sin cos cos 2 cos2 sin 2 2cos 2 1 1 2sin 2 sin( ) sin cos cos sin cos( ) cos cos sin sin sin sin 2sin cos 2 2 sin sin 2 cos sin 2 2 cos cos 2 cos cos 2 2 cos cos 2sin sin 2 2 Cosine rule a 2 b 2 c 2 2bc cos A Sine rule a b c sin A sin B sin C 28 Series Expansion x 2 x3 e 1 x ... , 2! 3! e0 1, x e x x 2 x3 1 x ... , 2! 3! ln(1 x) x sin x x x 2 x3 ... 2 3 x 3 x5 ... 3! 5! sinh x x x3 x 5 3! 5! e e 0 ln 1 0, ln 0 , ln for |x| < 1 cos x 1 x 2 x4 ... 2! 4! cosh x 1 1 1 x x 2 x3 x 4 1 x x x 2 x3 5 4 1 x 1 x 2 8 16 128 tan x x x3 2 5 x 3 15 x2 x4 x3 2 tanh x x x5 2! 4 ! 3 15 1 1 2 x 3x 2 4 x3 5 x 4 6 x5 2 1 x 1 x 3 5 25 4 1 x 2 x3 x 2 8 16 128 1 x Binomial Series: if x 1 (1 x) n 1 nx n(n 1) n n x2 x3 n(n 1)(n 2) ... , equivalently (1 x)n x k 2! 3! k 0 k Binomial Expansion n n1 n n 2 2 n n 1 n n n n! x y x y xy y where 1 2 n 1 n k k ! n k ! x y n x n Maclaurin Series Expansion of a Function f(x) x2 d 2 f x3 d 3 f xn d n f df f x f 0 x 2 3 n n ! dx 0 dx 0 2! dx 0 3! dx 0 The derivative’s subscript means evaluate at x = 0 Taylor Series Expansion of a Function f(x) x x0 df f x f x0 x x0 2! dx x0 2 d2 f 2 dx x x0 n! x0 n dn f n dx x0 The derivative’s subscript means evaluate at x = x0 29 i 1, i 2 1, i 1/ i Complex Numbers Cartesian representation z x iy ‘real’ part Re( z ) x ‘imaginary’ part Im( z ) y Re z r cos Polar representation z rei Complex conjugate z x iy rei Modulus (Absolute value) squared Im( z) r sin z z z x iy x iy x2 y 2 2 Relationship between representations arctan y / x if x 0 x r cos y r sin / 2 if x 0 and y 0 / 2 if x 0 and y 0 r x2 y 2 arctan y / x if x 0 Euler’s Identity ei cos i sin eix eix sin x 2i eix eix cos x 2 sinh x i sin ix cosh x i cos x e x e x sinh x 2 De Moivre’s Formula e x e x cosh x 2 z n r n einx r n cos x i sin x r n cos nx i sin nx n Spherical Polar to Cartesian Coordinate Conversion A point [ x, y, z] in Cartesian coordinates is represented by a polar angle , an azimuthal (or equatorial) angle and a radius r, i.e. [ r, , ]. These are related as which means that x r sin cos y r sin sin z r cos r x2 y 2 z 2 cos z / r tan y / x The volume element is dV r sin d dr rd r 2 sin drd d 30 Glossary of selected Mathematical Symbols Symbols Meaning ab Equality, with numbers 3.14159 three dots are added. ab a is not equal to b ab Identity; a is identical to b a b a 2 2ab b 2 . Rarely used. ab a is less than b, ab a is greater than b. ≤ less than or equal to ≥ greater than or equal to mean much less than 2 much greater than ab a is approximately equal to b ab a is of the order of b, or a changes at the same rate as b 373 K 100°C Indicates change of units to equivalent value a values are plus and minus a a values are minus and plus a a^b a , a / b, a b b a raised to power b. Used only in computer languages a b, a b a is perpendicular and parallel to b respectively Infinity tends to, or approaches and used as in a or a 0 a is divided by b Angle n Summation, xi x0 x1 x2 xn i 0 n Product, xi x0 x1x2 xn i 0 n O(x ) Big ‘O’ notation. In series expansion to indicate that the next, unwritten terms do not grow faster than xn. x 1 if x 0 else is zero (x) delta function nm Kronecker delta nm 1 if m n else is zero. m and n are integers df x / dx f x , f x f , f [A, B] Derivative of function f with respect to x. Alternative notation. First and second derivatives of function f with respect to x. Alternative notation. First and second derivatives, usually with respect to time. Commutator brackets, with operators A and B 31 Using MAPLE Maple can be used in different modes, the simplest is to use the worksheet mode which means that the text is in red preceded by the red symbol >. To force the programme to use this mode, click in the [> icon on the toolbar at the top of the screen, then click the text icon in the lower tool bar on the left part of the screen. Next, using the tools menu, locate and click on options, then interface and select default for new worksheets and using the drop down menu select worksheet. Complete the setup by closing the options box by clicking on apply globally. Maple should start in the worksheet mode next time it is used. When manipulating algebraic expressions, the syntax always has the form > Your_name_for_something:= expression; Curved brackets always follow functions such as sin, cos, log or your own functions, e. g. sin(3*x)*ln(x^2) or pre-defined terms such as plot(x^2, x=-2..2); > restart: # always start this way. The symbol # starts a comment > z:= sin( x /(1+x) ); # use brackets when dividing > a_Gaussn:= exp( -x^2/20 ); > f1:= simplify( (x^2)^(1/2), symbolic ); > y:= diff( x^2, x); # differentiate by x > eV:= convert(1,units, kJ, electronvolt); # convert kJ to eV > plot(3+x-x^4,x=-3..3,view=[-1..2,-3..4],color=blue); > ans:= solve(a*x^2+b*x+c=0,x); # solve for x > # Your own functions are defined as > func:= ( x, y)-> exp(-x^2) + sin(y^2) + 2; # user defined function > # and used as, for example, > sin(x)* func(3.0); > y:= func(x^2); > plot(func(s),s=0..3*Pi,colour=[blue],view=[0..10, 0..4],numpoints =1000); > # convenient way to show integration (or differentiation) and result > Int(sin(x)^2,x = a..b): % = value(%); Further Maple instructions can be found on the Phys. Chem. (Porter) lab computers 32