Electron domain
Any area where there is a significant amount of electron density
The electron domain geometry (EDG) depends on?
ONLY on the number of electron domains are around the central atom.
The molecular geometry (MG) depends on?
How many of the electron domains around the central atom are lone pairs.
Two electron domains=
linear (180degrees)
Three electron domains=
Trigonal (120degrees)
Three e- domains and zero nonbonding pairs
Trigonal planar
Trigonal planar
Three e- domains and one nonbonding pair
Trigonal planar
Bent
Four electron domains=
Tetrahedral
Four e- domains and one nonbonding pair
Tetrahedral
Trigonal pyramidal
Four e- domains and two nonbonding pair
Tetrahedral
Bent
Five electron domains
Trigonal Bipyramidal
Five e- domains and one nonbonding pair
Trigonal Bipyramidal
See-Saw
Five e- domains and two nonbonding pairs
Trigonal Bipyramidal
T-shaped
Five e- domains and three nonbonding pairs
Trigonal Bipyramidal
linear
Six electron domains=
Octahedral
Six e- domains and one nonbonding pair
Octahedral
Square pyramidal
Six e- domains and two nonbonding pairs
Octahedral
Square planar
Intermolecular forces
-forces that occur between molecules
-the interactions holding two different molecules together
What are the three types of intermolecular forces in pure substances?
1. Dipole- Dipole
2. Dispersion forces (London)
3. Hydrogen bonding
(VAN DER WALS)
Why do intermolecular forces matter?
Determine the phase of matter!
Stronger IMF's (intermolecular) mean higher melting and boiling points. True or False?
True
Dipole- Dipole
Polar molecules exhibit a permanent seperation of charge. (The poles of the molecules are attracted to poles of the opposite charge.)
Dispersion Forces
All molecules can have temporary dipoles due to the random motion of electrons. (The strength of dispersion forces is affected by the polarizability of the electrons in the molecule.)
Hydrogen Bonding
An intermolecular attraction between a hydrogen atom bonded to a highly EN atom and a lone pair on a small, highly EN atom. Occurs when H is bonded directly to Oxygen, Nitrogen, and Florine. (Really a strong dipole)
Dispersion < Dipole- Dipole < H- bonding , is this the correct order?
yes
Ion-Dipole attractions
Attraction between Ions and Dipoles. (most commonly occurs when ionic solids dissolve in water.)
Coulomb's law
Ion-Dipole attraction increases with increasing charge and decreasing radius ion.
Hybridization
The carbon orbitals involved in CH4 bonding are clearly not s & p anymore they are hybrids
What is the number of hybrid orbitals determined by?
The number of electron domains
The number of hybrid orbitals obtained is equal to what?
The number of atomic orbitals hybridized
e- domains = hybrid orbitals = atomic orbitals, True or false?
True
Sigma bonds
All single bonds are sigma bonds
Pi bonds
All double bonds are pi bonds
The hybridization of an atom does not change between resonance structures (even if they appear too), True or False?
True
Isomers
Molecules with the same molecular formula but different arrangement of atoms
cisisomer
like groups are on the same side of the double bonds
Transisomer
like groups are on the opposite side of the double bond