Chapter 11 Flashcards
How are positions of electron groups determined?
by trying to minimize repulsions between them
Electron groups around central atom are most stable when
they are as far apart as possible
What does VSEPR stand for?
Valence Shell Electron Pair Repulsion
What is bond angle and number of electron groups for linear electron geometry
bond angle 180, 2
What is bond angle and number of electron groups for trigonal planar electron geometry
120,3
What is bond angle and number of electron groups for tetrahedral electron geometry
109.5,4
What is the bond angle and number of electron groups for trigonal bipyramidal geometry?
90 axial, 120 equitorial, 5 electron groups
What is the bond angle and number of electron groups for octahedron
all 90, 6 electron groups
What do double bonds do to electrons?
repel electrons more
electron geometry
geometrical arrangement of electron groups
molecular geometry
geometrical arrangement of atoms, lone pairs occupy space on the central atom but at not “seen” as points on the molecular geometry
Put the relative sizes of repulsive forces from biggest to smallest
Lone pair to lone pair> lone pair to bonding pair> bonding pair to bonding pair
What is the molecular geometry of a tetrahedral electron geometry with 4 electron groups and 0 lone pairs?
Molecular geometry is tetrahedral
What is the molecular geometry of tetrahedral electron geometry with one lone pair??
Molecular geometry is trigonal pyramidal
What is the molecular geometry of tetrahedral electron geometry with two lone pairs
Molecular geometry is bent
What position will the lone pair occupy?
The position that minimizes repulsion
Where do lone pairs go when there are five electron groups around the central atom?
They will occupy equatorial positions because there is more room
What are the bond angles between equatorial positions when there are five electron groups around central atom with one lone pair?
bond angles between equatorial positions are less than 120 and bond angles between axial and equatorial positions rea less than 90
What is the molecular geometry when there’s one lone pair and five electron groups around the central atom?
seesaw
What is the molecular geometry when there are 5 electron groups around central atoms and two lone pairs? what are the bond angles?
T shaped , less than 90 degrees
What is the molecular geometry when there are 5 electron groups around central atom and 3 lone pairs? What are the bond angles?
Linear, 180 degrees
Where do lone pairs go when there’s 6 electron groups and some are lone pairs?
each even number lone pair will take a position opposite the pervious lone pair
What is the molecular geometry of six electron groups around central atom and one is a lone pair? what are bond angles?
square pyramid shape less than 90
What is the molecular geometry of six electron groups around central atom and two are lone pairs? what are bond angles?
square planar shape, less than 90
dipole moment is a measure of what?
bond polarity
dipole moment is directly proportional to what?
the size of partial charges (q) and the distance r between then
dipole moment is measured in what?
debeys
what does it mean if there’s a net dipole moment?
molecule is polar, no net moment it’s nonpolar
CH bonds are always
nonpolar
if the EN difference is between 0-0.4, what is the bond type
covalent
if the EN difference is between 0.4 and 2, what is the bond type
polar covalent
If the EN difference is 2 or greater, the bond type is
ionic
