Inorganic hemistry review sheet Exam #1 h. 1 General hemistry review reaction types: A/B, redox., single displacement, elimination, addition, rearrangement and solvolysis types of substances: elements, ionic, molecular Memorize Periodic Table Periodic Table: metal/metalloid/non-metal Groups (vertical) alkali metals, alkaline earth metals, transition metals., pnictogens, chalcogens, halogens, noble gas Periods (horizontal) Thermodynamics Kinetics 1 st Law: E = q + w Gibbs Free Energy, ΔG = ΔH TΔS Enthalpy, ΔH = q p Entropy, ΔS disorder, S = k lnw Stable (ΔG = +) vs. unstable (ΔG = ) Inert (slow) vs. Labile (fast) h. 2 reaction profile: E vs. reaction progress The atom Quantum Theory: Plank and Einstein. E is quantized Rutherford s Au foil experiment: atomic model
Bohr model of the atom: E given to the atom puts the e in an excited state, drops back down to the ground state (a specific orbit; a specific E drop, a specific color). Visible line spectrum of H 2 : E is artificially quantized via the orbits from the Bohr model debroglie: e has particle-like and wave-like characteristics. Standing waves are quantized; quantization a natural result of the model. = h / mv e : Particle-like nature: Einstein (photoelectric effect) Wave-like nature: Davisson Germer Schrödinger wave equation uses both properties of e Ψ is the e. The Ψ describes the e in terms of location and E. or simply, H = E where H is the Hamiltonian operator 2 Y/ wrt: x, y, z Goal: Describe an e in an atom via the wavefunction: has no physical meaning, so Born interpretation (Ψ 2 = probability of finding the e ) Acceptable s mathematically must be: 1. Normalized 2. Single valued at x,y,z 3. ontinuous 4. Finite is quantized with only certain values (quantum numbers: n, l, m l ) an more easily separate out angle ( ) and distance data (r) if spherical polar coordinates are used instead of artesian coordinates. E exactly solvable for H and 1e species: per atom Ψ consists of R(r) (radial function) (R(r) 2 = probability as a function of distance) and Y (angular function; spherical harmonic) (Y 2 = probability as a function of angle). 4 Quantum #s: n: Principle QN; E and size. Any whole # integer from 1 to ( means e is completely removed from atom) l: Orbital angular momentum (azmithul QN); shape from e movement. Any whole # value up to n 1
m l : Magnetic QN; orientation, moving e generates a magnetic field. Values from l up to +l m s : e can be spin up (+1/2) or down ( 1/2) Wavefunction Equations and Orbital plots Radial - R Radial Density R 2 Radial Probability onion shell 4πr 2 R 2 s, p, d (know shape, name, label axes), f orbitals gerade vs. ungerade (i) What is the interpretation of the drawing? Wavefunction itself (no physical meaning), angular part of wavefunction squared probability at angles (out to infinity), or contour plot 90% probability (includes R 2 and, hence, n). Looking at a one e atom: all orbitals with the same n are degenerate because the one e isn t being shielded by any other e s. Atoms with more than one e show differences in E between orbitals with the same n because of shielding. (s orbitals shield (see below) best, and thus are lowest in E). an model with Self onsistent Field (SF) model. E for more than 1e species: per atom Z* Effective nuclear charge Z* = Z S Z; atomic number (# of p + ) S; Shielding (screening) constant s, p: close to nucleus: screened less by inner e. More effective at screening outer e. d, f: screened more by inner e & poor at screening. Ground state e configuration from Periodic Table (Pauli Exclusion Principle, Aufbau and Hund s Rule;, where N, # of e with parallel spin. over all orbitals. K, exchange integral ( 1 (1) 2 (2) with 1 (2) 2 (1)) ). Valence e s Exchange Energy maximized with number of parallel spins
Ground state e configuration anomalies (know: r (exchange energy) and u) TM Anomalous e onfigurations Periodic Table should be based on atomic numbers (Z) NOT e filling anomalies! Orbital filling: Paramagnetic, contains unpaired e s, attracted to a magnetic field. Diamagnetic, contains paired e s, repelled by a magnetic field. Slater s Rules (Shielding): Screening constant estimated from Slater's Rules: Divide orbitals in groups of n & s,p or d or f: 1s 2s,2p 3s,3p 3d 4s,4p 4d 4f 1. e of interest s or p: a. e s in same group each contribute 0.35 (35%) b. n 1 each contribute 0.85 (85%) c. n 2 & below each contribute 1.00 (100%) 2. e of interest d or f: a. e s in same group each contribute 0.35 b. n 1 & below each contribute 1.00 Periodic Trends: Size, IE, EA, e configurations of ions (and reasoning behind all) Size: Lanthanide contraction makes 3 rd to 4 th row of transition metals smaller than expected IE 1 (1 st ionization energy; one e removed), IE 2 (2 nd ionization energy; 2 nd e removed) EA 1 (1 st e affinity; 1 st e added), EA 2 (2 nd e affinity; 2 nd e added) (if adding e is favorable, the EA value will be negative).
h. 3 Symmetry operation Symmetry elements (point symmetry): 1. enter of symmetry (or inversion) i, point 2. Rotation (or proper) axis n, line 3. Mirror, plane Types: h to the principle axis, n v containing the principle axis, n d s bisecting 2 2 s 4. Rotation reflection (or improper) axis S n, line 5. Identity E, no element Group Theory When all the symmetry elements in a molecule are collected, it is found that they have the properties of a mathematical group. 1. Product of 2 elements of a group the same as another element of the group. AB = 2. There is the identity operator, E. EA = A 3. Every element has an inverse which is an element of the group. A 1 A = E 4. Associative law holds: A(B) = (AB) Point Group: All the mathematical operations (symmetry elements) constitute a group; the symmetry elements intersect in at least one point. (If all of the symmetry operations were performed, at least one point remains unchanged). Point groups represented by Schoenflies symbol. Shorthand for all the symmetry of an object (molecule). Some ex.s of point groups: 1 E i E, i s E, s 2 E, 2 D 3 E, 2 3, 3 2 2v E, 2, v (xy), v (yz) 2h E, i, 2, h D 2d E, 2 S 4, 2, 2 2, 2 d D 4h E, 2 4, 2, 2 2, 2 2, i, 2 S 4, h, 2 v, 2 d T d E, 8 3, 3 2, 6 S 4, 6 d O h E, 8 3, 6 2, 6 4, 3 2, i, 6 S 4, 8 S 6, 3 h, 6 d v E, 2, v D h E, 2, v, i, 2 S, 2 I h E, 12 5, 20 3, 15 2, i, 12 S 10, 20 S 6, 15 Note: There is no D nv, O v or T v
Do not have to find all the symmetry to assign point group: 1. Linear? v or D h 2. High symmetry? Multiple n, n > 2 I x, or O x 3. Highest n T x, nx or D nx 4. 2 s? D nx 5. Mirrors? h : nh or D nh ; just v (d): nv or D nd Assigning Point Groups (know how to draw in necessary symmetry elements to validate the Point Group chosen): haracter Tables (see haracter Tables): Point Group symbol, Mulliken symbol, Symmetry Elements, Irreducible Representations, haracters, orbitals, rotation axes Applications of Symmetry & Group Theory Optical Activity, dipole moments, IR (and Raman) Spectroscopy, NMR, Bonding and Orbitals, rystallography an apply the symmetry elements contained in the Group to see what happens to the molecule (orbitals in the molecule): Symmetry operations can leave a vector: unchanged, 1; inverted, 1; or translated, 0 The mathematical result can be used to see if a stretch of a bond will be seen in the IR spectrum, can use results to make MO diagrams, etc Simpler approaches are knowing the point group of a molecule allows the prediction of the number of peaks in an NMR spectrum.
IA VIIIA 1 H 1.008 IIA Periodic Table of the Elements IIIB IVB VB VIB VIIB VIII IB IIB IIIA IVA VA VIA VIIA 2 He 4.003 3 Li 6.941 4 Be 9.012 5 B 10.811 6 12.011 7 N 14.007 8 O 15.999 9 F 18.998 10 Ne 20.180 11 Na 22.990 12 Mg 24.305 13 Al 26.982 14 Si 28.086 15 P 30.974 16 S 32.065 17 l 35.453 18 Ar 39.948 19 K 39.098 20 a 40.078 21 Sc 44.956 22 Ti 47.867 23 V 50.942 24 r 51.996 25 Mn 54.938 26 Fe 55.845 27 o 58.933 28 Ni 58.693 29 u 63.546 30 Zn 65.409 31 Ga 69.723 32 Ge 72.64 33 As 74.921 34 Se 78.96 35 Br 79.904 36 Kr 83.798 37 Rb 85.468 38 Sr 87.62 39 Y 88.906 40 Zr 91.224 41 Nb 92.906 42 Mo 95.94 43 Tc (98) 44 Ru 101.07 45 Rh 102.906 46 Pd 106.42 47 Ag 107.868 48 d 112.411 49 In 114.818 50 Sn 118.710 51 Sb 121.760 52 Te 127.60 53 I 126.904 54 Xe 131.293 55 s 132.905 56 Ba 137.327 71 Lu 174.967 72 Hf 178.49 73 Ta 180.948 74 W 183.84 75 Re 186.207 76 Os 190.23 77 Ir 192.217 78 Pt 195.078 79 Au 196.967 80 Hg 200.59 81 Tl 204.383 82 Pb 207.2 83 Bi 208.980 84 Po (209) 85 At (210) 86 Rn (222) 87 Fr (223) 88 Ra 226.025 103 Lr (262) 104 Rf (267) 105 Db (270) 106 Sg (271) 107 Bh (270) 108 Hs (277) 109 Mt (278) 110 Ds (281) 111 Rg (281) 112 n (285) 113 ((284) 114 (289) 115 ) (289) 116 (291) 117 (294) 118 (294) 57 La 138.906 58 e 140.116 59 Pr 140.908 60 Nd 144.24 61 Pm (145) 62 Sm 150.36 63 Eu 151.964 64 Gd 157.25 65 Tb 158.925 66 Dy 162.500 67 Ho 164.930 68 Er 167.259 69 Tm 168.934 70 Yb 173.04 89 Ac 227.028 90 Th 232.038 91 Pa 231.036 92 U 238.029 93 Np 237.048 94 Pu (244) 95 Am (243) 96 m (247) 97 Bk (247) 98 f (251) 99 Es (252) 100 Fm (257) 101 Md (258) 102 No (259)