Looking for something specific in this course? The compiles links to most course resources in a single page.
| Modules | Bonding and Molecules |
| Concepts | linear combination of atomic orbitals–molecular orbitals (LCAO-MO): energy level diagrams, bonding and anti-bonding orbitals, and hybridization, paramagnetism and diamagnetism |
| Keywords | Wolfgang Pauli, primary bond, ionic bond, covalent bond, metallic bond, electronegativity, metal, non-metal, superposition, alkali metal, node, lobe, nodal plane, electron density, alloy, electronic conductivity, ionic conductivity, molten salt, liquid metal, energy level diagram, atomic orbital, molecular orbital, bonding orbital, antibonding orbital, paramagnetism, sigma bond, pi bond, hybridization, single bond, double bond, triple bond, diamagnetism, octet stability, polar bond, polar molecule, nonpolar molecule, homonuclear molecule, heteronuclear molecule, Schrödinger’s equation, linear superposition, atomic orbital wavefunction, conservation of orbital states, Aufbau principle, quantum numbers, Pauli exclusion principle, Hund’s rule, bonding electron, nonbonding electron, unpaired electrons, Lewis structure, electron transfer |
| Chemical Substances | ethylene (C2H4), methane (CH4), carbon (C), acetylene (C2H2), titanium tetrachloride (TiCl4), sulfur hexafluoride (SF6), bromine pentafluoride (BrF5), iodine tetrafluoride (IF4-), helium (He), dilithium (Li2), disodium (Na2), nitrogen (N2), oxygen (O2), fluorine (F2) |
| Applications | sodium vapor lamps |
Before starting this session, you should be familiar with:
Prof. Sadoway discusses the shapes of molecules (Session 11).
After completing this session, you should be able to:
Archived Lecture Notes #2 (PDF), Section 3
| Book Chapters | Topics |
|---|---|
| [Saylor] 9.2, “Localized Bonding and Hybrid Atomic Orbitals.” | Valence bond theory: a localized bonding approach; hybridization of s and p orbitals; hybridization using d orbitals |
| [Saylor] 9.3, “Delocalized Bonding and Molecular Orbitals.” | Molecular orbital theory: a delocalized bonding approach; bond order in molecular orbital theory; molecular orbitals formed from ns and np atomic orbitals; molecular orbital diagrams for second-period homonuclear diatomic molecules; molecular orbitals in heteronuclear diatomic molecules |
| [Saylor] 9.4, “Combining the Valence Bond and Molecular Orbital Approaches.” | Multiple bonds; molecular orbitals and resonance structures |
Prof. Sadoway discusses the following concepts:
| [Saylor] Sections | Conceptual | Numerical |
|---|---|---|
| [Saylor] 9.2, “Localized Bonding and Hybrid Atomic Orbitals.” | none | 1, 2, 7, 8 |
| [Saylor] 9.3, “Delocalized Bonding and Molecular Orbitals.” | none | 1, 2, 6, 7, 11, 13, 14, 18 |
Wolfgang Pauli - 1945 Nobel Prize in Physics
| Content | Provider | Level | Notes |
|---|---|---|---|
| 5.111 Principles of Chemical Science | MIT OpenCourseWare | Undergraduate (first-year) |
| Modules | Bonding and Molecules |
| Concepts | shapes of molecules: valence shell electron pair repulsion (VSEPR), sigma and pi bonds, and octet stability |
| Keywords | bonding electron, nonbonding electron, hybridized orbital, linear combination of atomic orbitals–molecular orbitals (LCAO-MO), valence shell electron pair repulsion (VSEPR), octahedral, square pyramidal, square planar, trigonal bipyramid, polar bond, non-polar bond, planar, see-saw conformation, dipole, refractive index, electrical conductivity, covalent bond, ionic bond, expanded octet, electron domain, lone pair, molecular skeleton, Lewis structure, bonding orbital, sigma bond, pi bond, triple bond, octet rule |
| Chemical Substances | ethylene (C2H4), methane (CH4), carbon (C), acetylene (C2H2), titanium tetrachloride (TiCl4), sulfur hexafluoride (SF6), bromine pentafluoride (BrF5), iodine tetrafluoride (IF4-) |
| Applications | None |
Before starting this session, you should be familiar with:
Prof. Sadoway completes the Bonding and Molecules module with a session on secondary bonding, permanent and induced dipoles, hydrogen bonding, and polarizability of molecules (Session 12).
After completing this session, you should be able to:
| Book Chapters | Topics |
|---|---|
| [Saylor] 9.1, “Predicting the Geometry of Molecules and Polyatomic Ions.“ | The VSEPR model; using the VSEPR model; molecular dipole moments |
Prof. Sadoway discusses the following:
He re-emphasizes the underlying point of this unit: equal bond energies imply equal spatial disposition, and electronic structure dictates bond disposition, which further dictates molecular architecture.
| [Saylor] Sections | Conceptual | Numerical |
|---|---|---|
| [Saylor] 9.1, “Predicting the Geometry of Molecules and Polyatomic Ions.“ | 1, 3, 7, 14 | none |
| [Saylor] 9.4, “Polyatomic Systems with Multiple Bonds.“ | 1 | none |
| Content | Provider | Level | Notes |
|---|---|---|---|
| 5.111 Principles of Chemical Science | MIT OpenCourseWare | Undergraduate (first-year) |
Lecture 15: Valence Bond Theory and Hybridization Lecture 16: Thermochemistry |
| Modules | Bonding and Molecules |
| Concepts | secondary bonding, permanent and induced dipoles (London dispersion/van der Waals), hydrogen bonding, polarizability of molecules |
| Keywords | permanent dipole, induced dipole, hydrogen bond, polarity, London dispersion, electronegativity, melting point, boiling point, intermolecular bond, solid, liquid, gas, van der Waals force, secondary bond, dipole moment, polarizability, state of aggregation, Fritz London, Johann van der Waals |
| Chemical Substances | hydrochloric acid (HCl), argon (Ar), iodine (I2), methane (CH4), helium (He), propane (C3H8), octane (C8H18), eicosane (C20H42), hydrofluoric acid (HF), ammonia (NH3), water (H2O) |
| Applications | liquid water supports life; methane sea on Titan; states of hydrocarbons at STP |
Before starting this session, you should be familiar with prior topics in Bonding & Molecules (Session 8 onwards), especially:
Water has unusual properties due to its hydrogen bonds, which will be explored further in the modules covering Aqueous Solutions (Session 25, Session 26) and Biochemistry (Session 30 onwards). Experimental data about the state of a material at varying temperature and pressure is summarized in its phase diagram, the topic of Session 33 through Session 35.
After completing this session, you should be able to:
Archived Lecture Notes #2 (PDF), Section 4
| Book Chapters | Topics |
|---|---|
| [Saylor] 11.2, “Intermolecular Forces.” | Dipole-dipole interactions; London dispersion forces; hydrogen bonds |
| [JS] 2.5, “The Secondary, or van der Waals, Bond.” | Van der Waals bonding; permanent and induced dipoles; hydrogen bridge |
Substances in the aggregate may be solid, liquid, or gas at a given temperature and pressure. To predict the state of a substance, both intramolecular (primary bonds: ionic, covalent) and intermolecular forces must be taken into account. Prof. Sadoway discusses the following secondary bond types:
| [Saylor] Sections | Conceptual | Numerical |
|---|---|---|
| [Saylor] 11.2, “Intermolecular Forces.” | 9, 11, 14, 20, 24 | none |
Gavroglu, Kostas. Fritz London: A Scientific Biography. New York, NY: Cambridge University Press, 1995. ISBN: 9780521023191.
Israelachvili, Jacob. Intermolecular and Surface Forces. New York, NY: Academic Press, 1992. ISBN: 9780123751812.
Johannes Diderik van der Waals – 1910 Nobel Prize in Physics
| Content | Provider | Level | Notes |
|---|---|---|---|
| Properties of Water | HyperPhysics: Chemistry | High school | |
| Intermolecular Forces - Grade 11 | Connexions | High school | |
| 5.112 Principles of Chemical Science | MIT OpenCourseWare | Undergraduate (first-year) |
Start - 25:15 in Lecture 16: Intermolecular Interactions End - 38:15 in Lecture 17: Polarizability |
| 7.012 Introduction to Biology | MIT OpenCourseWare | Undergraduate (first-year) | Lecture 2: Biochemistry 1 |
| Modules | Bonding and Molecules |
| Concepts | ionic bonding: octet stability by electron sharing, energy of ion pairs vs. ion lattice, and properties of ionic crystals, enthalpy of reaction: Hess’s law, Born-Haber cycle |
| Keywords | Born exponent, cation, anion, covalent bond, ionic bond, valence shell electron pair repulsion model (VSEPR), interionic separation, crystal array, omnidirectional bond, unsaturated bond, Avogadro’s number, electrostatic energy, ionic solid, Madelung constant, melting point, boiling point, electrical insulator, hardness, brittle, soluble, polar solvent, noble gas, ionic liquid, photon, transparency, binding energy, hybridized bond, elasticity, enthalpy, ionization energy, sublimation, electron affinity, lattice energy, bonding electron, nonbonding electron, molecular architecture |
| Chemical Substances | sodium chloride (NaCl), manganese (Mn), sodium (Na), potassium (K), silver iodide (AgI), neon (Ne), magnesium oxide (MgO), aluminum (Al), aluminum oxide (Al2O3), cryolite (Na3AlF6) |
| Applications | design of thermal abrasion resistance materials, design of inert anode materials |
Before starting this session, you should be familiar with:
Prof. Sadoway discusses the shortcomings of ionic bonding and Lewis’s concept of shell filling by electron sharing including the Lewis dot notation (Session 9); and returns to the valence shell electron pair repulsion (VSEPR) model in Session 11: The Shapes of Molecules.
After completing this session, you should be able to:
Archived Lecture Notes #1 (PDF), Sections 6, 7
Archived Lecture Notes #2 (PDF), Sections 1, 2
| Book Chapters | Topics |
|---|---|
| [Saylor] 7.3, “Energetics of Ion Formation.” | Ionization energies; electron affinities; electronegativity |
| [Saylor] 8.1, “An Overview of Chemical Bonding.” | Review of chemical bonding; comparison of covalent and ionic bonds |
| [Saylor] 8.2, “Ionic Bonding.” | Electrostatic attraction and repulsion; potential energy at the bond distance |
| [Saylor] 8.3, “Lattice Energies in Ionic Solids.” | Calculating lattice energies; the relationship between lattice energies and physical properties; the Born-Haber cycle; predicting the stability of ionic compounds |
| [Saylor] 12.5, “Correlation between Bonding and the Properties of Solids.” | Ionic solids; molecular solids; covalent solids; metallic solids |
In this lecture, Prof. Sadoway discusses the following topics:
This lecture also introduces the valence shell electron pair repulsion (VSEPR) model, properties of covalent (saturated, directional) and ionic bonds, rules for determining molecular shapes, and the classification of each electron as a bonding electron (B) or a nonbonding electron (NB). Equal bond energies imply equal spatial disposition, and the electronic structure dictates bond disposition, which dictates molecular architecture.
| [Saylor] Sections | Conceptual | Numerical |
|---|---|---|
| [Saylor] 8.3, “Lattice Energies in Ionic Solids.” | 7, 9 | 4, 5, 6 |
| [Saylor] 8.4, “Lewis Electron Dot Structures.” | 2 | none |
| [Saylor] 8.5, “Lewis Structures and Covalent Bonding.” | 3 | 7, 9, 13, 18 |
| [Saylor] 8.6, “Exceptions to the Octet Rule.” | 2 | 4 |
| [Saylor] 9.1, “Predicting the Geometry of Molecules and Polyatomic Ions.” | none | 1, 5 |
Born, Max. My Life: Recollections of a Nobel Laureate. New York, NY: Scribner, 1978. ISBN: 9780684156620.
Born, Max. Physics in My Generation. New York, NY: Springer-Verlag, 1969.
Born, Max. Atomic Physics. New York, NY: Hafner Publications, 1970. ISBN: 9780486659848.
Stoltzenberg, Dietrich. Fritz Haber: Chemist, Nobel Laureate, German, Jew. Philadelphia, PA: Chemical Heritage Press, 2004. ISBN: 9780941901246.
Charles, Daniel. Master Mind: The Rise and Fall of Fritz Haber, the Nobel Laureate who Launched the Age of Chemical Warfare. New York, NY: Ecco, 2005. ISBN: 9780060562724.
Fritz Haber - 1918 Nobel Prize in Chemistry
Max Born - 1954 Nobel Prize in Physics
| Content | Provider | Level | Notes |
|---|---|---|---|
| 5.111 Principles of Chemical Science | MIT OpenCourseWare | Undergraduate (first-year) | |
| Chemical Bonds | HyperPhysics: Chemistry | High school |
| Modules | Bonding and Molecules |
| Concepts | Lewis structures: octet stability, partial charge, bonding and nonbonding electrons, electronegativity: polar bonds and polar molecules, ionic character of covalent bonds, Coulomb’s law |
| Keywords | cation, anion, Madelung constant, enthalpy, valence electron, Gilbert Lewis, ionization, isoelectronic, metal, nonmetal, ionic bond, electron transfer, electron sharing, covalent bond, percent ionic character, homonuclear bond, heteronuclear bond, triple bond, dative bond, s and p orbitals, Lewis structures, Linus Pauling, hybrid orbital, crystallization energy, bond energy, charge displacement, dipole moment, polar covalency, electronegativity, polar bond, polar molecule |
| Chemical Substances | sodium (Na), chloride (Cl), nitrogen (N), oxygen (O), lithium (Li), beryllium (Be), magnesium (Mg), aluminum (Al), silicon (Si), hydrogen (H), helium (He), sulfuryl chloride (SO2Cl2), methane (CH4), magnesium chloride (MgCl2), hydrogen fluoride (HF), hydrogen chloride (HCl), sodium chloride (NaCl), Freon-12 |
| Applications | capacitors, refrigerant, compressor design |
Before starting this session, you should be familiar with:
Prof. Sadoway discusses hybridized and molecular orbitals along with paramagnetism (Session 10).
After completing this session, you should be able to:
Archived Lecture Notes #2 (PDF), Section 3
| Book Chapters | Topics |
|---|---|
| [Saylor] 7.3, “Energetics of Ion Formation.” | Ionization energies; electron affinities; electronegativity |
| [Saylor] 8.4, “Introduction to Lewis Dot Structures.” | Creating a Lewis dot symbol; the octet rule |
| [Saylor] 8.5, “Lewis Structures and Covalent Bonding.” | Using electron structures to describe covalent bonding; using Lewis electron structures to explain stoichiometry; using formal charges to distinguish between Lewis structures; resonance structures |
| [Saylor] 8.6, “Exceptions to the Octet Rule.” | Odd number of electrons; more than an octet of electrons; fewer than an octet of electrons |
| [Saylor] 8.8, “Properties of Covalent Bonds.” | Bond order; the relationship between bond order and bond energy; the relationship between molecular structure and bond energy |
| [Saylor] 8.9, “Polar Covalent Bonds.” | Bond polarity; dipole moments |
Prof. Sadoway discusses the following concepts:
| [Saylor] Sections | Conceptual | Numerical |
|---|---|---|
| [Saylor] 7.3, “Energetics of Ion Formation.” | 1, 10 | none |
| [Saylor] 8.2, “Ionic Bonding.” | none | 3 |
| [Saylor] 8.6, “Exceptions to the Octet Rule.” | none | 1, 7 |
| [Saylor] 8.9, “Polar Covalent Bonds.” | none | 2, 6, 7, 8 |
| [Saylor] 9.1, “Predicting the Geometry of Molecules and Polyatomic Ions.” | none | 7 |
Molina, Mario J. and Rowland, F. S. “Stratospheric sink for chlorofluoromethanes: chlorine atomc-atalysed destruction of ozone.” Nature 249 (June 28, 1974): 810-812.
Linus Pauling - 1954 Nobel Prize in Chemistry, 1962 Nobel Prize in Peace
Fritz Haber - 1918 Nobel Prize in Chemistry
| Content | Provider | Level | Notes |
|---|---|---|---|
| 5.111 Principles of Chemical Science | MIT OpenCourseWare | Undergraduate (first-year) |
This self-assessment page completes the Bonding and Molecules module, and covers material from the following sessions.
On this page are a simple weekly quiz and solutions; relevant exam problems and solutions from the 2009 class; help session videos that review selected solutions to the exam problems; and supplemental exam problems and solutions for further study.
This short quiz is given approximately once for every three lecture sessions. You should work through the quiz problems in preparation for the exam problems.
These exam problems are intended for you to demonstrate your personal mastery of the material, and should be done alone, closed-book, with just a calculator, the two permitted reference tables (periodic table, physical constants), and one 8 1/2" x 11" aid sheet of your own creation.
After you’ve taken the exam, watch the help session videos below for insights into how to approach some of the exam problems.
In these videos, 3.091 teaching assistants review some of the exam problems, demonstrating their approach to solutions, and noting some common mistakes made by students.
Clip 4: Exam 2, Problem 5 - Part One
Clip 5: Exam 2, Problem 5 - Part Two
These additional exam problems from prior years’ classes are offered for further study.
