Physical Chemistry II Recommended Problems Chapter 12( 23)
|
|
- Lawrence Allen
- 5 years ago
- Views:
Transcription
1 Physical Chemistry II Recommended Problems Chapter 1( 3) Chapter 1(3) Problem. Overlap of two 1s orbitals recprobchap1.odt 1
2 Physical Chemistry II Recommended Problems, Chapter 1(3), continued Chapter 1 Problem 3 MO diagram of CO. Energies of the molecular orbitals are not known. The energies graphed below are just guesses. Chapter 1 Problem 5 Greater bond order implies shorter bond. Calculate bond order. Greater bond order implies shorter bond. molecule or molecular ion configuration number of bonding electrons number of antibonding electrons bond order bond length order Li σ g 0 1 shorter Li + σ g / C g u 1 u 4 6 shorter C + g u 1 u 3 5 3/ O g u 1 u 4 3 g 1 g 8 4 O + g u 1 u 4 3 g 1 g / shorter F g u 1 u 4 3 g 1 g shorter F - g u 1 u 4 3 g 1 g 4 3 u / recprobchap1.odt
3 Physical Chemistry II Recommended Problems, Chapter 1(3), continued Chapter 1(3) Problem 6 sketch the HOMO for N +, Li +, O -, H -, and C +. Chapter 1(3) Problem 7 Why is IE of CO greater than IE of NO? The answer is based on the MO diagram for N because CO is isoelectronic to N and the electron configuration of NO is like that of N -. NO has one more electron than CO, and that extra electron is in an antibonding molecular orbital. Ionization of NO occurs from a higher-energy orbital than ionization of CO, so NO has the smaller ionization energy. recprobchap1.odt 3
4 Physical Chemistry II Recommended Problems, Chapter 1(3), continued Chapter 1(3) Problem 9 Calculate hydrogen-fluoride AO coefficients at S HF =0.45. ψ 1 = ϕ H1s + ϕ Fpz ψ = c H ϕ H1s + c F ϕ Fpz = 13.6eV H FF = 18.6 ev H HF = 1.75S HF H FF equations to use to find coefficients secular determinant H HF S HF H HF S HF H FF = 0 Expanding the determinant gives a quadratic equation for E. The first row of the secular equation gives this connection between and ( ) +(H HF S HF ) =0 which can be rearranged to normalization = H HF S HF + c 1F + S HF = 1 normalization can be written in terms of C 1F and the ratio. ( C ) c 1H 1F + C + c SHF 1F = 1 1F substitution of the ratio above reduces the normalization formula to just one variable [( C H HF S HF ) ( 1F + 1 S H HF S )] HF HF = 1 Division and taking the square root yields ±1 = ( H HF S ) HF + 1 ( H HF S ) HF S HF Here is a sample calculation for the case S HF = H HF = X 0.45 X (5.96) 1/ = ev The expanded determinant is (1 - S HF) E + ( H HF S HF - -H FF ) E + ( H FF - H HF ) = 0 For S HF =0.45, E E = 0 The lower-energy solution is E = ev. (The larger solution is ev.) Continuing with the case S HF =0.45, ( / ) = ±1 Then = = ( ) Finally (again, for S HF =0.45) = The determinant can be checked for the case S HF =0.45. recprobchap1.odt 4
5 secular determinant (without rounding) = = = Likewise, normalization and the secular equation can be used to check and. + + S HF = X 0.45 X X = ( - E) + (H HF - S HF E) = ( ) ( X 0.45) = = 0, as required. This table shows the results for S HF = 0.30 and S HF E ground (ev) = H HF S HF To better see the effect of S HF, Larger overlap increases interaction substitute 1.75 S HF H FF for H HF 1.75 = S H FF + E c HF 1F energy and electron sharing, increasing the ratio of H to F orbital coefficients. recprobchap1.odt 5
6 Physical Chemistry II Recommended Problems, Chapter 1(3), continued Chapter 1(3) Problem 14 bonding in O, O -, and O +. molecule or molecular ion configuration number of unpaired electrons O σg σu 1πu 4 3σg 1πg O - σ g σu 1πu 4 3σg 1πg 3 1 O + σ g σu 1πu 4 3σg 1πg 1 1 The HOMO for O, 1π g *, is antibonding. Adding an electron to make O - weakens the bond. Removing an electron to make O + strengthens the bond. Bond strength: O - < O < O +. Chapter 1(3) Problem 15. Calculate dipole moment from bond length and MO coefficients. R e =91.7pm. MO coefficients are c H =0.34 and c F =0.84. Overlap S HF =0.30. Electron density (from this MO) assigned to H and to F are: n e,h = ( c H + S HF c H c F ) = ( X 0.34 X 0.84) = ( ) = X 0.01 = 0.40 n e,f = ( c F + S HF c H c F ) = ( X 0.34 X 0.84) = ( ) = X = 1.58 which I rounded to 1.60 so n e,h +n e,f =. That number accounts for only one fluorine electron, the F electron that pairs with the H electron to make a bond in this MO. I will add the other 8 fluorine electrons to n e,f. n e.f = = Atomic charge is nuclear charge minus electron charge. The nuclear charge of H is 1, so q H = = 0.60 The nuclear charge of Fe is 9. q F = = (the opposite of the H charge, as it must be) Dipole moment = (q H - q F )R e = X0.60 (1.60X10-19 Coulomb/e) X 91.7X10-1 m μ = 1.0 X 1.60X10-19 C X 91.7X10-1 m = 1.76X10-9 C m Divide by 3.33X10-30 C m/debye. μ = 5.3 D. (This is approximately twice the answer given by Engel in the back of the book.) The experimental dipole moment is 1.91 Debye, a factor of.8 smaller. A Hartree-Fock STO-3G calculation gives charge separation, using the Mulliken method that is comparable to the method used above, of X0.0 = That is a factor of 3 smaller than the X0.60 = 1.0 calculated above. recprobchap1.odt 6
7 Chapter 1 Problem 19 sketch MO energy diagram for OH based on the diagram for FH The diagram for OH will be similar, but the Os and Op orbitals will be higher in energy than the Fs and Fp orbitals because O has a smaller nuclear charge than does F. OH has one fewer valence electron than has HF, so OH will have one unpaired electron and will have a doublet ground-state spin. As in HF, the HOMO will be nonbonding (oxygen p x and p y orbitals) and the LUMO will be antibonding (σ*). The valence MO diagram at right shows orbitals calculated using Hartree-Fock theory and the minimal STO-3G basis set. There is qualitative agreement with the HF MO diagram above. recprobchap1.odt 7
8 Physical Chemistry II Recommended Problems, Chapter 1(3), continued Chapter 1 Problem 1. Valence MO energies for HF When the overlap is small (equivalent to the atoms being far apart) then E 1 and E approximately equal the F and H orbital energies. Increasing S 1 causes greater interaction, lowering E 1 and raising E. recprobchap1.odt 8
In this lecture we will understand how the molecular orbitals are formed from the interaction of atomic orbitals.
Lecture 7 Title: Understanding of Molecular Orbital Page-1 In this lecture we will understand how the molecular orbitals are formed from the interaction of atomic orbitals. We will see how the electrons
More informationLUMO + 1 LUMO. Tómas Arnar Guðmundsson Report 2 Reikniefnafræði G
Q1: Display all the MOs for N2 in your report and classify each one of them as bonding, antibonding or non-bonding, and say whether the symmetry of the orbital is σ or π. Sketch a molecular orbital diagram
More informationBonding and Physical Properties The Molecular Orbital Theory
Bonding and Physical Properties The Molecular Orbital Theory Ø Developed by F. Hund and R. S. Mulliken in 1932 Ø Diagram of molecular energy levels Ø Magnetic and spectral properties Paramagnetic vs. Diamagnetic
More informationCHEM J-5 June 2014
CHEM1101 2014-J-5 June 2014 The molecular orbital energy level diagrams for H 2, H 2 +, H 2 and O 2 are shown below. Fill in the valence electrons for each species in its ground state and label the types
More informationChem Spring, 2017 Assignment 5 - Solutions
Page 1 of 10 Chem 370 - Spring, 2017 Assignment 5 - Solutions 5.1 Additional combinations are p z ± d z 2, p x ±d xz, and p y ±d yz. p z ± d z 2 p x ±d xz or p y ±d yz 5.2 a. Li 2 has the configuration
More information4 Diatomic molecules
s manual for Burrows et.al. Chemistry 3 Third edition 4 Diatomic molecules Answers to worked examples WE 4.1 The Lewis model (on p. 174 in Chemistry 3 ) Use the Lewis model to describe the bonding in (a)
More informationValence bond theory accounts, at least qualitatively, for the stability of the covalent bond in terms of overlapping atomic orbitals.
Molecular Orbital Theory Valence bond theory accounts, at least qualitatively, for the stability of the covalent bond in terms of overlapping atomic orbitals. Using the concept of hybridization, valence
More informationLecture B6 Molecular Orbital Theory. Sometimes it's good to be alone.
Lecture B6 Molecular Orbital Theory Sometimes it's good to be alone. Covalent Bond Theories 1. VSEPR (valence shell electron pair repulsion model). A set of empirical rules for predicting a molecular geometry
More informationWhat Do Molecules Look Like?
What Do Molecules Look Like? The Lewis Dot Structure approach provides some insight into molecular structure in terms of bonding, but what about 3D geometry? Recall that we have two types of electron pairs:
More information11/29/2014. Problems with Valence Bond Theory. VB theory predicts many properties better than Lewis Theory
Problems with Valence Bond Theory VB theory predicts many properties better than Lewis Theory bonding schemes, bond strengths, bond lengths, bond rigidity however, there are still many properties of molecules
More informationMolecular-Orbital Theory
Prof. Dr. I. Nasser atomic and molecular physics -551 (T-11) April 18, 01 Molecular-Orbital Theory You have to explain the following statements: 1- Helium is monatomic gas. - Oxygen molecule has a permanent
More informationAnswers to Practice Test Questions 3 Molecular Orbital Theory: Heteronuclear Diatomic Molecules
Answers to Practice Test Questions 3 Molecular Orbital Theory: Heteronuclear Diatomic Molecules 1. The electron configuration for HH is 1ss 1, so HH has 1 valence electron. The electron configuration for
More informationIFM Chemistry Computational Chemistry 2010, 7.5 hp LAB2. Computer laboratory exercise 1 (LAB2): Quantum chemical calculations
Computer laboratory exercise 1 (LAB2): Quantum chemical calculations Introduction: The objective of the second computer laboratory exercise is to get acquainted with a program for performing quantum chemical
More information3: Many electrons. Orbital symmetries. l =2 1. m l
3: Many electrons Orbital symmetries Atomic orbitals are labelled according to the principal quantum number, n, and the orbital angular momentum quantum number, l. Electrons in a diatomic molecule experience
More informationMolecular Orbital Theory
Molecular Orbital Theory 1. MO theory suggests that atomic orbitals of different atoms combine to create MOLECULAR ORBITALS 2. Electrons in these MOLECULAR ORBITALS belong to the molecule as whole 3. This
More informationDrawing Lewis Structures
Chapter 2 - Basic Concepts: molecules Bonding models: Valence-Bond Theory (VB) and Molecular Orbital Theory (MO) Lewis acids and bases When both of the electrons in the covalent bond formed by a Lewis
More informationSame idea for polyatomics, keep track of identical atom e.g. NH 3 consider only valence electrons F(2s,2p) H(1s)
XIII 63 Polyatomic bonding -09 -mod, Notes (13) Engel 16-17 Balance: nuclear repulsion, positive e-n attraction, neg. united atom AO ε i applies to all bonding, just more nuclei repulsion biggest at low
More informationMidterm Exam I. CHEM 181: Introduction to Chemical Principles September 24, 2015 Key
Midterm Exam I CHEM 8: Introduction to Chemical Principles September 24, 205 Key. A Li 2+ ion in an unknown, highly excited electronic state, first emits a photon at a wavelength of 4.36 µm, and following
More informationMolecular Orbital Theory
Molecular Orbital Theory Paramagnetic properties of O 2 pranjoto utomo Covalent Bonding Theory Valence Bond Theory useful for deriving shapes/polarity simple but inaccurate/deficient Molecular Orbital
More informationCHAPTER TEN MOLECULAR GEOMETRY MOLECULAR GEOMETRY V S E P R CHEMICAL BONDING II: MOLECULAR GEOMETRY AND HYBRIDIZATION OF ATOMIC ORBITALS
CHAPTER TEN CHEMICAL BONDING II: AND HYBRIDIZATION O ATOMIC ORBITALS V S E P R VSEPR Theory In VSEPR theory, multiple bonds behave like a single electron pair Valence shell electron pair repulsion (VSEPR)
More informationwith the larger dimerization energy also exhibits the larger structural changes.
A7. Looking at the image and table provided below, it is apparent that the monomer and dimer are structurally almost identical. Although angular and dihedral data were not included, these data are also
More informationChapter 9: Molecular Geometry and Bonding Theories
Chapter 9: Molecular Geometry and Bonding Theories 9.1 Molecular Geometries -Bond angles: angles made by the lines joining the nuclei of the atoms in a molecule -Bond angles determine overall shape of
More informationChapter 9. Chemical Bonding II: Molecular Geometry and Bonding Theories
Chapter 9 Chemical Bonding II: Molecular Geometry and Bonding Theories Topics Molecular Geometry Molecular Geometry and Polarity Valence Bond Theory Hybridization of Atomic Orbitals Hybridization in Molecules
More informationMolecular Orbitals. Based on Inorganic Chemistry, Miessler and Tarr, 4 th edition, 2011, Pearson Prentice Hall
Molecular Orbitals Based on Inorganic Chemistry, Miessler and Tarr, 4 th edition, 2011, Pearson Prentice Hall Images from Miessler and Tarr Inorganic Chemistry 2011 obtained from Pearson Education, Inc.
More informationCHAPTER 11 MOLECULAR ORBITAL THEORY
CHAPTER 11 MOLECULAR ORBITAL THEORY Molecular orbital theory is a conceptual extension of the orbital model, which was so successfully applied to atomic structure. As was once playfuly remarked, a molecue
More informationMolecular Geometry and Bonding Theories. Chapter 9
Molecular Geometry and Bonding Theories Chapter 9 Molecular Shapes CCl 4 Lewis structures give atomic connectivity; The shape of a molecule is determined by its bond angles VSEPR Model Valence Shell Electron
More informationOrganic Chemistry. Review Information for Unit 1. Atomic Structure MO Theory Chemical Bonds
Organic Chemistry Review Information for Unit 1 Atomic Structure MO Theory Chemical Bonds Atomic Structure Atoms are the smallest representative particle of an element. Three subatomic particles: protons
More informationTheoretical Chemistry - Level II - Practical Class Molecular Orbitals in Diatomics
Theoretical Chemistry - Level II - Practical Class Molecular Orbitals in Diatomics Problem 1 Draw molecular orbital diagrams for O 2 and O 2 +. E / ev dioxygen molecule, O 2 dioxygenyl cation, O 2 + 25
More informationChemistry 3211 Coordination Chemistry Part 3 Ligand Field and Molecular Orbital Theory
Chemistry 3211 Coordination Chemistry Part 3 Ligand Field and Molecular Orbital Theory Electronic Structure of Six and Four-Coordinate Complexes Using Crystal Field Theory, we can generate energy level
More informationGeneral Chemistry I (2012) Lecture by B. H. Hong
3.8 The Limitations of Lewis's Theory 3.9 Molecular Orbitals The valence-bond (VB) and molecular orbital (MO) theories are both procedures for constructing approximate wavefunctions of electrons. The MO
More informationChapter 10: Chemical Bonding II. Bonding Theories
Chapter 10: Chemical Bonding II Dr. Chris Kozak Memorial University of Newfoundland, Canada Bonding Theories Previously, we saw how the shapes of molecules can be predicted from the orientation of electron
More informationThe symmetry properties & relative energies of atomic orbitals determine how they react to form molecular orbitals. These molecular orbitals are then
1 The symmetry properties & relative energies of atomic orbitals determine how they react to form molecular orbitals. These molecular orbitals are then filled with the available electrons according to
More informationGeneral Physical Chemistry II
General Physical Chemistry II Lecture 13 Aleksey Kocherzhenko October 16, 2014" Last time " The Hückel method" Ø Used to study π systems of conjugated molecules" Ø π orbitals are treated separately from
More informationLecture 9 Electronic Spectroscopy
Lecture 9 Electronic Spectroscopy Molecular Orbital Theory: A Review - LCAO approximaton & AO overlap - Variation Principle & Secular Determinant - Homonuclear Diatomic MOs - Energy Levels, Bond Order
More informationCHEM-UA 127: Advanced General Chemistry I
CHEM-UA 7: Advanced General Chemistry I I. LINEAR COMBINATION OF ATOMIC ORBITALS Linear combination of atomic orbitals (LCAO) is a simple method of quantum chemistry that yields a qualitative picture of
More informationChapter 10 Chemical Bonding II
Chapter 10 Chemical Bonding II Valence Bond Theory Valence Bond Theory: A quantum mechanical model which shows how electron pairs are shared in a covalent bond. Bond forms between two atoms when the following
More informationUsing Symmetry to Generate Molecular Orbital Diagrams
Using Symmetry to Generate Molecular Orbital Diagrams review a few MO concepts generate MO for XH 2, H 2 O, SF 6 Formation of a bond occurs when electron density collects between the two bonded nuclei
More informationone ν im: transition state saddle point
Hypothetical Potential Energy Surface Ethane conformations Hartree-Fock theory, basis set stationary points all ν s >0: minimum eclipsed one ν im: transition state saddle point multiple ν im: hilltop 1
More informationOrganic Chemistry Lecture I. Dr. John D. Spence
HEMISTRY 3 Organic hemistry Lecture I Dr. John D. Spence jdspence@scu.edu jspence@csus.eduedu http://www.csus.edu/indiv/s/spencej What is Organic hemistry? 780 s hemistry of compounds from living organisms
More informationMolecular Orbital Theory. Molecular Orbital Theory: Electrons are located in the molecule, not held in discrete regions between two bonded atoms
Molecular Orbital Theory Valence Bond Theory: Electrons are located in discrete pairs between specific atoms Molecular Orbital Theory: Electrons are located in the molecule, not held in discrete regions
More informationΨ g = N g (1s a + 1s b ) Themes. Take Home Message. Energy Decomposition. Multiple model wave fns possible. Begin describing brain-friendly MO
Themes Multiple model wave fns possible Different explanations of bonding Some you have seen before Errors vary (not consistently better or worse) Convenience varies Brain v. algebra v. computer Where
More informationANNOUNCEMENTS. If you have questions about your exam 2 grade, write to me or Chapter 8 homework due April. 13 th.
ANNOUNCEMENTS If you have questions about your exam 2 grade, write to me or Chem200@mail.sdsu.edu. Chapter 8 homework due April. 13 th. Chapter 9 home work due April. 20th. Exam 3 is 4/14 at 2 pm. LECTURE
More informationTYPES OF SYMMETRIES OF MO s s-s combinations of orbitals: , if they are antibonding. s-p combinatinos of orbitals: CHEMICAL BONDING.
TYPES OF SYMMETRIES OF MO s s-s combinations of : Orbitals Molecular Orbitals s s Node s s (g) (g) Bonding orbital Antibonding orbital (u) 4 (u) s-s combinations of atomic In the bonding MO there is increased
More informationA Computer Study of Molecular Electronic Structure
A Computer Study of Molecular Electronic Structure The following exercises are designed to give you a brief introduction to some of the types of information that are now readily accessible from electronic
More information5.04 Principles of Inorganic Chemistry II
MIT OpenCourseWare http://ocw.mit.edu 5.04 Principles of Inorganic Chemistry II Fall 008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. 5.04, Principles
More informationChemistry 543--Final Exam--Keiderling May 5, pm SES
Chemistry 543--Final Exam--Keiderling May 5,1992 -- 1-5pm -- 174 SES Please answer all questions in the answer book provided. Make sure your name is clearly indicated and that the answers are clearly numbered,
More informationChemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 10
Chemical Bonding II: Molecular Geometry and Hybridization of Atomic Orbitals Chapter 10 Linear Trigonal 180 o planar 120 o Tetrahedral 109.5 o Trigonal Bipyramidal 120 and 90 o Octahedral 90 o linear Linear
More information7. Arrange the molecular orbitals in order of increasing energy and add the electrons.
Molecular Orbital Theory I. Introduction. A. Ideas. 1. Start with nuclei at their equilibrium positions. 2. onstruct a set of orbitals that cover the complete nuclear framework, called molecular orbitals
More informationPHYSICAL CHEMISTRY I. Chemical Bonds
PHYSICAL CHEMISTRY I Chemical Bonds Review The QM description of bonds is quite good Capable of correctly calculating bond energies and reaction enthalpies However it is quite complicated and sometime
More information8.1 Types of Chemical Bonds List and define three types of bonding. chapter 8 Bonding General Concepts.notebook. September 10, 2015
chapter 8 Bonding General Concepts.notebook Chapter 8: Bonding: General Concepts Mar 13 11:15 AM 8.1 Types of Chemical Bonds List and define three types of bonding. Bonds are forces that hold groups of
More informationChem 3502/4502 Physical Chemistry II (Quantum Mechanics) 3 Credits Spring Semester Christopher J. Cramer. Lecture 30, April 10, 2006
Chem 3502/4502 Physical Chemistry II (Quantum Mechanics) 3 Credits Spring Semester 20056 Christopher J. Cramer Lecture 30, April 10, 2006 Solved Homework The guess MO occupied coefficients were Occupied
More informationChapter 9. Molecular Geometry and Bonding Theories
Chapter 9. Molecular Geometry and Bonding Theories PART I Molecular Shapes Lewis structures give atomic connectivity: they tell us which atoms are physically connected to which atoms. The shape of a molecule
More informationChapter 5. Molecular Orbitals
Chapter 5. Molecular Orbitals MO from s, p, d, orbitals: - Fig.5.1, 5.2, 5.3 Homonuclear diatomic molecules: - Fig. 5.7 - Para- vs. Diamagnetic Heteronuclear diatomic molecules: - Fig. 5.14 - ex. CO Hybrid
More informationChemistry: The Central Science. Chapter 9: Molecular Geometry and Bonding Theory
Chemistry: The Central Science Chapter 9: Molecular Geometry and Bonding Theory The shape and size of a molecule of a particular substance, together with the strength and polarity of its bonds, largely
More informationσ u * 1s g - gerade u - ungerade * - antibonding σ g 1s
One of these two states is a repulsive (dissociative) state. Other excited states can be constructed using linear combinations of other orbitals. Some will be binding and others will be repulsive. Thus
More informationChapter 8. Molecular Shapes. Valence Shell Electron Pair Repulsion Theory (VSEPR) What Determines the Shape of a Molecule?
PowerPoint to accompany Molecular Shapes Chapter 8 Molecular Geometry and Bonding Theories Figure 8.2 The shape of a molecule plays an important role in its reactivity. By noting the number of bonding
More informationReikniefnafræði - Verkefni 1 Haustmisseri 2013 Kennari - Hannes Jónsson
Háskóli Íslands, raunvísindasvið Reikniefnafræði - Verkefni 1 Haustmisseri 2013 Kennari - Hannes Jónsson Guðjón Henning 11. september 2013 A. Molecular orbitals and electron density of H 2 Q1: Present
More informationChapter 9: Molecular Geometries and Bonding Theories Learning Outcomes: Predict the three-dimensional shapes of molecules using the VSEPR model.
Chapter 9: Molecular Geometries and Bonding Theories Learning Outcomes: Predict the three-dimensional shapes of molecules using the VSEPR model. Determine whether a molecule is polar or nonpolar based
More informationCHEM1901/ J-5 June 2013
CHEM1901/3 2013-J-5 June 2013 Oxygen exists in the troposphere as a diatomic molecule. 4 (a) Using arrows to indicate relative electron spin, fill the left-most valence orbital energy diagram for O 2,
More informationChemical Bonding. Lewis Theory-VSEPR Valence Bond Theory Molecular Orbital Theory
Chemical Bonding Lewis Theory-VSEPR Valence Bond Theory Molecular Orbital Theory Problems with Valence Bond Theory VB theory predicts properties better than Lewis theory bonding schemes, bond strengths,
More informationChapter 9. Molecular Geometries and Bonding Theories. Lecture Presentation. John D. Bookstaver St. Charles Community College Cottleville, MO
Lecture Presentation Chapter 9 Theories John D. Bookstaver St. Charles Community College Cottleville, MO Shapes The shape of a molecule plays an important role in its reactivity. By noting the number of
More informationChapter 7: Chemical Bonding and Molecular Structure
Chapter 7: Chemical Bonding and Molecular Structure Ionic Bond Covalent Bond Electronegativity and Bond Polarity Lewis Structures Orbital Overlap Hybrid Orbitals The Shapes of Molecules (VSEPR Model) Molecular
More information2. Constructive and destructive interference (in phase and out-of-phase interaction) a. Sigma bond is achieved by head on overlap
Discussion #1 Chapter 10 CH102 2018 MOs TF s name: Your name: Discussion Section: 1. Atomic Orbital (s, p, d, f) vs. Molecular Orbital (σ, σ *, NB, π, π *, π nb ) a. Total Number of MO =Total Number of
More informationWave Equations of Polyatomic Molecules
Wave Equations of Polyatomic Molecules! Approximate wave functions are sought by combining atomic wave functions for the bonded atoms.! Several different approaches have been taken to constructing trial
More informationChapter 10. Structure Determines Properties! Molecular Geometry. Chemical Bonding II
Chapter 10 Chemical Bonding II Structure Determines Properties! Properties of molecular substances depend on the structure of the molecule The structure includes many factors, including: the skeletal arrangement
More informationChemistry 121: Topic 4 - Chemical Bonding Topic 4: Chemical Bonding
Topic 4: Chemical Bonding 4.0 Ionic and covalent bonds; Properties of covalent and ionic compounds 4.1 Lewis structures, the octet rule. 4.2 Molecular geometry: the VSEPR approach. Molecular polarity.
More information1s atomic orbital 2s atomic orbital 2s atomic orbital (with node) 2px orbital 2py orbital 2pz orbital
Atomic Orbitals 1s atomic orbital 2s atomic orbital 2s atomic orbital (with node) 2px orbital 2py orbital 2pz orbital Valence Bond Theory and ybridized Atomic Orbitals Bonding in 2 1s 1s Atomic Orbital
More informationThe wavefunction that describes a bonding pair of electrons:
4.2. Molecular Properties from VB Theory a) Bonding and Bond distances The wavefunction that describes a bonding pair of electrons: Ψ b = a(h 1 ) + b(h 2 ) where h 1 and h 2 are HAOs on adjacent atoms
More informationd 2 dx 2. H = 2 2m p 0 dξ 2 H = 2m e ma2 H = 1 2m dξ 2
CHAPTER 14 The Origins of Chemical Bonding SECTION 14.1 14.1 A proton (of mass m p ) in a 1-D box of length L = 10a 0, the system in part (a), has a Hamiltonian we write in terms of the ordinary length
More informationChemistry 431. Lecture 14. Wave functions as a basis Diatomic molecules Polyatomic molecules Huckel theory. NC State University
Chemistry 431 Lecture 14 Wave functions as a basis Diatomic molecules Polyatomic molecules Huckel theory NC State University Wave functions as the basis for irreducible representations The energy of the
More informationMOLECULAR STRUCTURE. Molecular Structure - B. Molecular Structure - B. Molecular Structure - B. Molecular Structure - B. Molecular Structure - B
MOLECULAR STRUCTURE Molecular Orbital all orbitals of the appropriate symmetry contribute to a molecular orbital. Bundet Boekfa Chem Div, Faculty Lib Arts & Sci Kasetsart University Kamphaeng Saen Campus
More informationChapter 10. VSEPR Model: Geometries
Chapter 10 Molecular Geometry VSEPR Model: Geometries Valence Shell Electron Pair Repulsion Theory Electron pairs repel and get as far apart as possible Example: Water Four electron pairs Farthest apart
More informationStructure and Bonding of Organic Molecules
Chem 220 Notes Page 1 Structure and Bonding of Organic Molecules I. Types of Chemical Bonds A. Why do atoms forms bonds? Atoms want to have the same number of electrons as the nearest noble gas atom (noble
More informationANNOUNCEMENTS. If you have questions about your exam 2 grade, write to me or Chapter 7 homework due Nov, 9 th.
ANNOUNCEMENTS If you have questions about your exam 2 grade, write to me or Chem200@sdsu.edu. Chapter 7 homework due Nov, 9 th. Chapter 8 homework due Nov. 16 th. Exam 3 is 11/17 at 2 pm. LECTURE OBJECTIVES
More informationAndrew Rosen *Note: If you can rotate a molecule to have one isomer equal to another, they are both the same
*Note: If you can rotate a molecule to have one isomer equal to another, they are both the same *Note: For hybridization, if an SP 2 is made, there is one unhybridized p orbital (because p usually has
More informationChemistry 1B, Fall 2012 Lectures 15-16
Chemistry 1B Fall 2012 Quantum Mechanics of the Covalent Bond for chapter 14 animations and links see: http://switkes.chemistry.ucsc.edu/teaching/chem1b/www_other_links/ch14_links.htm 1 LISTEN UP!!! WE
More information5.03 In-Class Exam 2
5.03 In-Class Exam 2 Christopher C. Cummins March 12, 2010 Instructions Clearly write your name at the top of this front page, but otherwise do not write on this front page as it will be used for scoring.
More informationBe H. Delocalized Bonding. Localized Bonding. σ 2. σ 1. Two (sp-1s) Be-H σ bonds. The two σ bonding MO s in BeH 2. MO diagram for BeH 2
The Delocalized Approach to Bonding: The localized models for bonding we have examined (Lewis and VBT) assume that all electrons are restricted to specific bonds between atoms or in lone pairs. In contrast,
More informationChemical Bonding. The Octet Rule
Chemical Bonding There are basically two types of chemical bonds: 1. Covalent bonds electrons are shared by more than one nucleus 2. Ionic bonds electrostatic attraction between ions creates chemical bond
More informationLecture 14 Chemistry 362 M. Darensbourg 2017 Spring term. Molecular orbitals for diatomics
Lecture 14 Chemistry 362 M. Darensbourg 2017 Spring term Molecular orbitals for diatomics Molecular Orbital Theory of the Chemical Bond Simplest example - H 2 : two H atoms H A and H B Only two a.o.'s
More informationBe H. Delocalized Bonding. Localized Bonding. σ 2. σ 1. Two (sp-1s) Be-H σ bonds. The two σ bonding MO s in BeH 2. MO diagram for BeH 2
The Delocalized Approach to Bonding: The localized models for bonding we have examined (Lewis and VBT) assume that all electrons are restricted to specific bonds between atoms or in lone pairs. In contrast,
More informationMolecular Simulation I
Molecular Simulation I Quantum Chemistry Classical Mechanics E = Ψ H Ψ ΨΨ U = E bond +E angle +E torsion +E non-bond Jeffry D. Madura Department of Chemistry & Biochemistry Center for Computational Sciences
More informationMO theory considers the entire molecule at once not isolated electron pairs.
5. Molecular Orbital Theory READING: Chapter 2, Sections 2.7 2.10 MO theory considers the entire molecule at once not isolated electron pairs. Consequence: An electron pair can be bonding/non-bonding/anti-bonding
More informationChemistry 1B, Fall 2013 Lectures 15-16
Chemistry 1, Fall 2013 Lectures 1516 Chemistry 1 Fall 2013 Lectures 1516 Quantum Mechanics of the Covalent ond LISTEN UP!!! WE WILL E COVERING SECOND PRT OF CHPTER 14 (pp 676688) FIRST You will go CRZY
More informationLecture 12. Symmetry Operations. NC State University
Chemistry 431 Lecture 12 Group Theory Symmetry Operations NC State University Wave functions as the basis for irreducible representations The energy of the system will not change when symmetry Operations
More informationReikniefnafræði - Verkefni 2 Haustmisseri 2013 Kennari - Hannes Jónsson
Háskóli Íslands, raunvísindasvið Reikniefnafræði - Verkefni 2 Haustmisseri 2013 Kennari - Hannes Jónsson Guðjón Henning 18. september 2013 1 A. Molecular orbitals of N 2 Q1: Display all the MOs for N 2
More informationCHAPTER 6 CHEMICAL BONDING TEXT BOOK EXERCISE Q.1. Select the correct statement. i. An ionic compound A + B - is most likely to be formed when ii. iii. a. the ionization energy of A is high and electron
More informationWorksheet III. E ion = -Z eff 2 /n 2 (13.6 ev)
CHEM 362 SPRING 2017 M. Y. Darensbourg 3 rd Worksheet for Peer Learning Study Groups Worksheet III Useful Formulas: E ion = -Z 2 /n 2 (13.6 ev) μ(s. o. ) = 2 S (S + 1) E ion = -Z eff 2 /n 2 (13.6 ev) Ground
More informationSemi-Empirical MO Methods
Semi-Empirical MO Methods the high cost of ab initio MO calculations is largely due to the many integrals that need to be calculated (esp. two electron integrals) semi-empirical MO methods start with the
More informationLecture B8 Molecular Orbital Theory, Part 3. Moving to the Suburbs
Lecture B8 Molecular Orbital Theory, Part 3 Moving to the Suburbs Molecular Orbital Theory - LCAO-MO Robert S. Mulliken realized that a Linear Combination of Atomic Orbitals (LCAO) could be used to make
More informationFigure 1 Setting the charge in HF 2 -.
Self-Stud Problems / Eam Preparation compute the orbitals for (linear) -, draw and annotate a MO diagram consistent with the MOs ou observe o if ou have problems setting up the calculation, select Be and
More informationChapter 9. Molecular Geometries and Bonding Theories. Lecture Presentation. John D. Bookstaver St. Charles Community College Cottleville, MO
Lecture Presentation Chapter 9 Theories John D. Bookstaver St. Charles Community College Cottleville, MO Shapes The shape of a molecule plays an important role in its reactivity. By noting the number of
More informationChapter 9. Covalent Bonding: Orbitals. Copyright 2017 Cengage Learning. All Rights Reserved.
Chapter 9 Covalent Bonding: Orbitals Chapter 9 Table of Contents (9.1) (9.2) (9.3) (9.4) (9.5) (9.6) Hybridization and the localized electron model The molecular orbital model Bonding in homonuclear diatomic
More information3-1 Lewis Electron-Dot Diagram
3-1 Lewis Electron-Dot Diagram Lewis-dot diagrams, are diagrams that show the bonding between atoms of a molecule, & the lone pairs of electrons that may exist in the molecule. Duet rule Octet rule beyond
More informationChemistry 6 (9 am section) Spring Covalent Bonding
Chemistry 6 (9 am section) Spring 000 Covalent Bonding The stability of the bond in molecules such as H, O, N and F is associated with a sharing (equal) of the VALENCE ELECTRONS between the BONDED ATOMS.
More informationMolecular shape is only discussed when there are three or more atoms connected (diatomic shape is obvious).
Chapter 10 Molecular Geometry (Ch9 Jespersen, Ch10 Chang) The arrangement of the atoms of a molecule in space is the molecular geometry. This is what gives the molecules their shape. Molecular shape is
More informationLecture 10. Born-Oppenheimer approximation LCAO-MO application to H + The potential energy surface MOs for diatomic molecules. NC State University
Chemistry 431 Lecture 10 Diatomic molecules Born-Oppenheimer approximation LCAO-MO application to H + 2 The potential energy surface MOs for diatomic molecules NC State University Born-Oppenheimer approximation
More informationFor more info visit Chemical bond is the attractive force which holds various constituents together in a molecule.
Chemical bond:- Chemical bond is the attractive force which holds various constituents together in a molecule. There are three types of chemical bonds: Ionic Bond, Covalent Bond, Coordinate Bond. Octet
More informationSymmetry III: Molecular Orbital Theory. Reading: Shriver and Atkins and , 6.10
Lecture 9 Symmetry III: Molecular Orbital Theory Reading: Shriver and Atkins 2.7-2.9 and g 6.6-6.7, 6.10 The orbitals of molecules H H The electron energy in each H atom is -13.6 ev below vacuum. What
More informationChapter 10. VSEPR Model: Geometries
Chapter 10 Molecular Geometry VSEPR Model: Geometries Valence Shell Electron Pair Repulsion Theory Electron pairs repel and get as far apart as possible Example: Water Four electron pairs Two bonds Two
More information