chapter 7 chemical bonding and molecular...
TRANSCRIPT
![Page 1: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/1.jpg)
Chapter 7
Chemical Bonding and
Molecular Structure
![Page 2: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/2.jpg)
Three Types of Chemical Bonding
(1) Ionic: formed by electron transfer
(2) Covalent: formed by electron sharing
(3) Metallic: attraction between metal ions and their delocalized electrons
![Page 3: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/3.jpg)
![Page 4: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/4.jpg)
Ionic Bonding
Metal to Nonmetal; Metal to Polyatomic Ions
Examples: NaCl, MgCl2, NaNO3, NH4NO3
Binary Compounds:
Metals lose electrons and nonmetals gain electrons
Metal ions are called cations (positively charged)
Nonmetal ions are called anions (negatively charged)
![Page 5: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/5.jpg)
Cations are attracted to anions and form crystal lattices called ionic compounds
Example:
An atom of Na loses one electron to form Na+
An atom of Cl gains one electron to form Cl-
Na+ is attracted to Cl- to form neutral NaCl
Remember all compounds are neutral
![Page 6: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/6.jpg)
Ionic Bonding Question
Describe how calcium fluoride would form
from atoms of calcium and fluorine.
![Page 7: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/7.jpg)
Lewis Electron-dot Symbols
The Lewis dot symbol of an atom depicts the number of “s” and “p” electrons in the outer energy level.
The number of dots around the symbol of an element ranges from 1-8 and reflects the valence electrons for that particle.
Generally dots are placed around the element’s symbol one at a time starting at the 9 o’clock position and continuing clockwise with no more than two dots shown at 9-12-3-6 o’clock.
![Page 8: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/8.jpg)
Practicing Electron-Dot Symbols
Write the Lewis-dot symbols for:
Li Be B C N O F Ne
What is the Lewis-dot symbol for:
K S Al
![Page 9: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/9.jpg)
The Octet Rule
When atoms form bonds they lose, gain, or
share electrons to attain a filled outer shell
(either two or eight electrons).
![Page 10: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/10.jpg)
Use of Orbital Diagrams and
Electron Configurations in Bonding
Example: Lithium Fluoride
![Page 11: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/11.jpg)
![Page 12: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/12.jpg)
Another Example of an Ionic
Compound
Use electron-dot symbols to show how
aluminum oxide forms.
![Page 13: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/13.jpg)
The Ionic Bonding Model
Energy considerations in ionic bonding
Overall, energy is released when ions come together in the formation of a compound
However, the process of the formation of an ionic compound involves a number of steps
![Page 14: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/14.jpg)
Consider the simplified formation of the ionic
compound NaCl.
Let’s start with atoms of sodium and
chlorine.
A sodium atom has to lose one electron and
a chlorine atom has to gain one electron.
![Page 15: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/15.jpg)
To remove an electron from a sodium atom it
requires energy (ionization energy)
Na(atom) + energy Na+(ion) + e-
When an atom of chlorine gains an electron it
releases energy (electron affinity)
Cl(atom) + e- Cl-(ion) + energy
![Page 16: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/16.jpg)
When a Na+ and a Cl- ion come together into
a solid crystal a great amount of energy is
released (lattice energy).
Na+ + Cl- NaCl + energy
![Page 17: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/17.jpg)
Lattice Energy
Lattice Energy is the energy absorbed that occurs when an ionic solid is separatedinto isolated ions in the gas phase. (Delta H is positive)
Also, the energy released when gaseous ions come together to form the crystal. (Delta H is negative)
![Page 18: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/18.jpg)
Lattice energies for alkali metal-halogen
compounds
![Page 19: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/19.jpg)
Summary
Note that in comparing compounds of like
charges the smaller the ion, the greater
the lattice energy.
BUT …
![Page 20: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/20.jpg)
Lattice Energy is proportional to:
| charge M+ X charge NM-|
distance between nuclei
Which has the larger lattice energy?
KF or LiF
KF or CaF2
AlCl3 or AlBr3 or Al2S3
Note: Magnitude of charge dominates over size.
![Page 21: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/21.jpg)
Properties of Ionic Compounds
Rigid, fixed positions of ions in solid state
Hard, brittle
Conduct electricity when melted or dissolved in water
High melting (mp) and boiling points (bp).
Note: The larger the lattice energy, the higher the mp and bp
![Page 22: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/22.jpg)
![Page 23: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/23.jpg)
Covalent Bonding
Nonmetal to Nonmetal Attraction: Shared
electrons
Example
H. .H H-H
A single covalent bond is formed by 2 atoms
sharing 2 electrons. Each atom has ownership
of the 2 electrons.
![Page 24: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/24.jpg)
Covalent Bond Formation
![Page 25: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/25.jpg)
Problem Solving
Using Lewis Dot Structures, explain how F2
forms.
F F F-F
How many bonding pairs are present?
How many lone pairs or nonbonding pairs are present?
![Page 26: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/26.jpg)
Sharing of Bonding Pairs
Each atom in a covalent bond “counts” the
shared electrons as though they belong
entirely to that atom.
Let’s return to H2 and F2 and discuss the
meaning of this.
Another example: hydrogen fluoride
![Page 27: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/27.jpg)
Bond Energy and Bond Length
Bond Energy: The amount of energy
required to break a bond (endothermic).
It is also the amount of energy released
in bond formation (exothermic)
Bond Length: The distance between the
nuclei of the two bonded atoms.
![Page 28: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/28.jpg)
Examples of
Bond Strength/Bond Energy
C O C O C O
1070 kJ/mol 745 kJ/mol 358 kJ/mol
![Page 29: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/29.jpg)
Note: Larger atoms result in longer,
thus weaker bonds.
![Page 30: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/30.jpg)
Bond Energy and Chemical
Change
![Page 31: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/31.jpg)
![Page 32: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/32.jpg)
Electronegativity (EN)
Electronegativity is the ability of a bonded
atom to attract the shared electrons.
Change in Electronegativity ( EN) is the
difference in electronegativity of the two
bonded atoms.
![Page 33: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/33.jpg)
Ionic, Polar Covalent, and Nonpolar
Covalent Bonding
![Page 34: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/34.jpg)
Linus Pauling’s Work
![Page 35: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/35.jpg)
Problem Solving
Consider the C-O bond, what is the EN for this
bond?
Consider the Br-Br bond, what is the EN for this
bond?
Which of the bonds above is/are polar covalent?
…nonpolar covalent?
![Page 36: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/36.jpg)
![Page 37: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/37.jpg)
Illustrating Bond Polarity
Conventional Methods for Illustrating the
Polarity of a bond.
C-O N-H C-H S-O H-F
![Page 38: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/38.jpg)
Linus Pauling’s Work
![Page 39: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/39.jpg)
Lewis Dot Structures Review
Draw Lewis Dot Structures of:
SiO2
SO32-
HNO2
Place your answer(s) on the board.
![Page 40: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/40.jpg)
Exceptions to the Octet Rule
Examples:
Deficient Octet
BF3
Expanded Octet
H2SO4
Radicals
NO
![Page 41: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/41.jpg)
Resonance Structures
Consider the following molecules:
CO32-
C6H6
CH3COO-
Note: Atoms do not change position! Only
pi and lone pair electrons.
![Page 42: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/42.jpg)
Formal Charge
Determination of formal charge for each atom
within a molecule:
V.E. – (NB.E. + ½ B.E.) = formal charge
What are the formal charges of each atom in HCN?
What are the formal charges of each atom in NO3- ?
What are the formal charges of each atom in SO42- ?
![Page 43: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/43.jpg)
Selecting the Preferred
Lewis Dot Structure
Use the concept of formal charge to select
the preferred structure of the CON- ion.
![Page 44: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/44.jpg)
Valence Bond Theory
Central Themes:
• A covalent bond forms when orbitals of two atoms overlap and the overlap region is occupied by two electrons.
• The greater the overlap the stronger the bond.
• The stronger the bond the more stable the bond.
• Orbitals must become oriented so as to obtain the greatest overlap possible.
![Page 45: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/45.jpg)
Types of orbital overlap:
sigma (end-to-end)
pi (side-by-side)
Note: sigma bond side-by-side overlap is
not permitted.
![Page 46: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/46.jpg)
![Page 47: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/47.jpg)
Let’s Consider CH4
How can carbon form four bonds?
What is the shape of methane?
What are the bond angles?
![Page 48: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/48.jpg)
Hybrid Orbital Theory
Theory depicts a mix of the atomic orbitals (hybridize) to form the necessary number of orbitals needed for bonding.
The number of hybrid orbitals formed equals the number of atomic orbitals mixed.
The type of hybrid orbitals obtained varies with the type of atomic orbitals mixed.
![Page 49: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/49.jpg)
Types of Hybrid Orbitals
sp
sp2
sp3
sp3d
sp3d2
![Page 50: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/50.jpg)
sp Hybrids
Consider BeH2
Central Be needs two hybrid orbitals to
accommodate the two bonded H atoms.
To aid the visualization of sp hybrid
formation use an orbital diagram, shapes
of hybrids, and bond angles.
![Page 51: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/51.jpg)
Bond angles for sp hybrids = 180o
![Page 52: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/52.jpg)
Note: The bonding between the sp hybrid
orbital of beryllium and the “s” orbital of the
hydrogen atom is considered a sigma
bond overlap.
![Page 53: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/53.jpg)
sp2 Hybrids
Consider BF3
Central boron atom needs three hybrid
orbitals to accommodate three bonded
fluorine atoms.
Visual of hybrid orbital formation theory.
![Page 54: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/54.jpg)
Bond angles for sp2 hybrids = 120o
![Page 55: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/55.jpg)
Note: The bond involving the sp2 hybridized
orbital of boron is an end-to-end overlap
(sigma bond) with the “p” orbital of the
fluorine atom.
![Page 56: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/56.jpg)
sp3 Hybrids
Back to CH4
The central carbon atom needs four hybrid
orbitals.
![Page 57: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/57.jpg)
Bond angles between sp3 hybrids = 109.5o
![Page 58: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/58.jpg)
Other atoms using sp3 Hybrids
If the central atom has only two or three
(rather than four) bonded atoms, hybrid
orbitals may also contain the lone pairs of
electrons.
Examples: NH3 , H2O
![Page 59: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/59.jpg)
![Page 60: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/60.jpg)
sp3d Hybrids
Consider PCl5
The central phosphorus atom needs five hybrid
orbitals to accommodate the five bonded
chlorine atoms.
Note that since there is only one “s” orbital and
only three “p” orbitals available per energy
level, a “d” orbital must be used in the hybrid.
![Page 61: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/61.jpg)
Bond angles between sp3d hybrids = 90o (axial) and
120o (equatorial)
![Page 62: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/62.jpg)
sp3d2 Hybrids
Consider SF6
The six bonded atoms require six hybrids.
![Page 63: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/63.jpg)
Bond angles between sp3d2 hybrids = 90o
![Page 64: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/64.jpg)
Summary of Hybrid Theory
![Page 65: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/65.jpg)
Hybrid Quiz
Predict the type of hybrid orbital you would
expect in the central atom of the following
molecules:
SiH4 BH3 AsF5 AlCl3 SF4
![Page 66: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/66.jpg)
Multiple Bonds
Double Bond: A=B
One bond is a sigma bond
The other is a pi bond
Sigma bonds are formed by hybrid orbitals
overlapping.
Pi bonds are formed by unhybridized “p”
orbitals overlapping.
![Page 67: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/67.jpg)
Double Bond
![Page 68: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/68.jpg)
Triple Bond: A≡B
One bond is a sigma bond formed from
overlapping hybrid orbitals.
Two bonds are pi bonds formed from
overlapping “p” orbitals.
![Page 69: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/69.jpg)
Triple Bond
![Page 70: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/70.jpg)
Orbital Overlap and Molecular
Rotation
Sigma bonds allow free rotation of bonded
atoms.
Pi bond overlap restricts rotation of bonded
atoms.
Double bonds lead to cis- and trans-
isomers. Example: C2H2Cl2
![Page 71: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/71.jpg)
Quiz
Describe the type of hybrid orbitals used by
each carbon and oxygen atom in the
following molecule:O
C
C O
HH
H H
![Page 72: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/72.jpg)
Valence Shell Electron Pair Repulsion
Theory (VSEPR)Each group of valence electrons around a central atom is
located as far away from the other atoms as possible.
Strength of electron pair repulsions:
L.P.-L.P. > L.P.-B.P. > B.P.-B.P.
A “group” of electrons is defined as any number of electrons that occupies a space around an atom and may consist of a single, double, triple bond or lone pair of electrons.
The 3-dimensional arrangement of these groups determines the molecular arrangement (shape).
![Page 73: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/73.jpg)
Molecular Shape
The arrangement of the atoms around a
central atom determines the shape of the
molecule or portion of the molecule.
![Page 74: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/74.jpg)
Possible Shapes of Molecules
• Linear
• Bent
• Trigonal Planar
• Trigonal Pyramidal
• Square Planar
• Square Pyramidal
• Octahedral
• T-Shaped
• Seesaw
• Trigonal Bipyramidal
![Page 75: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/75.jpg)
Different Shapes of Molecules
(or portions of molecules)
Two electron groups around the central atom:
– Linear shape
– Bond angle = 180o
![Page 76: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/76.jpg)
![Page 77: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/77.jpg)
Three electron groups
Trigonal planar arrangement
Bond angles = 120o
![Page 78: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/78.jpg)
![Page 79: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/79.jpg)
• Four electron groups
– Tetrahedral arrangement
– Bond angles = 109.5o
![Page 80: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/80.jpg)
![Page 81: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/81.jpg)
Five electron groups
Bipyramidal arrangement
Consists of three equatorial groups
And two axial groups
![Page 82: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/82.jpg)
![Page 83: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/83.jpg)
Six electron groups
-Octahedral arrangement
-Bond angles = 90o
![Page 84: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/84.jpg)
![Page 85: Chapter 7 Chemical Bonding and Molecular Structurecf.linnbenton.edu/mathsci/physci/backusb/upload/Chapter 7.pdf · Three Types of Chemical Bonding (1) Ionic: formed by electron transfer](https://reader033.vdocument.in/reader033/viewer/2022051307/5ad3f0cc7f8b9a05208eaba4/html5/thumbnails/85.jpg)
Polar vs. Nonpolar Molecules
Generally speaking, a molecule will be nonpolar if …
(1) All of the bonded atoms (or groups of atoms) to the central atom are the same and equidistant from each other.
i.e. BH3 vs. BF3
(2) There are no lone pairs of electrons on the central atom(s).
(3) It is a hydrocarbon.