Chem 105 Quiz 7

steric number

steric number

number of atoms bonded to central atom + number of lone pairs on central atom

coordination number

the number of bonded atoms around a central atom

Basic Geometry of SN = 2

Linear

Basic Geometry of SN = 3

Trigonal Planar

Basic Geometry of SN = 4

Tetrahedral

Basic Geometry of SN = 5

Trigonal Bipyramidal

Basic Geometry of SN = 6

Octahedral

Repulsion order rule

• Lone pairs occupy more volume in an atom than bonded pairs do -LP-LP > LP-BP > BP-BP

Bent's Rule

-More Electronegative (smaller atomic radius) atoms Prefer axial positions and less electronegative (larger atomic radius ) prefer equatorial positions -Only applies to SN=5

SN = 2, LP = 0

Linear 180

SN = 3

trigonal planar, 120

SN = 3, LP = 1

Bent, <120

SN=4, LP=0

Tetrahedral, 109.5

SN=4, LP=1

trigonal pyramidal, <109.5

SN=4 LP=2

Bent, << 109.5

SN=5, LP=0

trigonal bipyramidal 90 (ax to eq) , 120(eq to eq)

SN= 5 LP= 1

See-saw, <90 (ax to eq) , <120(eq to eq)

SN=5, LP = 2

T-shaped, <90

SN=5, LP=3

Linear 180

SN=6, LP =0

Octahedral, 90

SN=6, LP=1

square pyramidal, <90

SN=6, LP=2

square planar, 90

SN=6, LP=3

T-shaped, <90

SN=6, LP=4

Linear, 180