Midterm 4

Question 1

steric #

Answer 1

bonded atoms + # electron pairs
—> EG
—> number of orbitals needed (# connected to central atom)

Question 2

coordination #

Answer 2

of bonded atoms

Question 3

Electron geometry (EG)

Answer 3

geometry including electron pairs

Question 4

Molecular geometry (MG)

Answer 4

geometry w/o electron pairs

Question 5

bond angle

Answer 5

angle between bonds

Question 6

AX2

Answer 6

steric #: 2
EG: linear
MG: linear
Bond angle: 180

Question 7

AX3

Answer 7

steric #: 3
EG: trigonal planar
MG: trigonal planar
Bond angle: 120

Question 8

AX2E

Answer 8

steric #: 3
EG: trigonal planar
MG: bent
Bond angle: <120

Question 9

AX4

Answer 9

steric #: 4
EG: tetrahedral
MG: tetrahedral
Bond angle: 109.5

Question 10

AX3E

Answer 10

steric #: 4
EG: tetrahedral
MG: trigonal pyramid
Bond angle: <109.5

Question 11

AX2E2

Answer 11

steric #: 4
EG: tetrahedral
MG: bent
Bond angle: <109.5 and <AX3E

Question 12

AX5

Answer 12

steric #: 5
EG: trigonal bipyramidal
MG: trigonal bipyramidal
Bond angle: 90 OR 120

Question 13

AX4E

Answer 13

steric #: 5
EG: trigonal bipyramidal
MG: see-saw
Bond angle: <90 OR <120

Question 14

AX3E2

Answer 14

steric #: 5
EG: trigonal bipyramidal
MG: T-shaped
Bond angle: <90

Question 15

AX2E3

Answer 15

steric #: 5
EG: trigonal bipyramidal
MG: linear
Bond angle: 180

Question 16

AX6

Answer 16

steric #: 6
EG: octahedral
MG: octahedral
Bond angle: 90

Question 17

AX5E

Answer 17

steric #: 6
EG: octahedral
MG: square pyramid
Bond angle: <90

Question 18

AX4E2

Answer 18

steric #: 6
EG: octahedral
MG: square planar
Bond angle: <90

Question 19

dipole moment

Answer 19

vector addition of the magnetic movement of polar bonds

Question 20

polarity of C-H’s

Answer 20

ALL NONPOLAR

Question 21

6 orbitals needed

Answer 21

sp^3d^2

Question 22

5 orbitals needed

Answer 22

sp^3d^1

Question 23

4 orbitals needed

Answer 23

sp^3

Question 24

3 orbitals needed

Answer 24

sp^2

Question 25

2 orbitals needed

Answer 25

sp

Question 26

What happens to ENERGY within hybridized orbitals?

Answer 26

Energy is combined, but number of orbitals remain the same

Question 27

sigma bonds

Answer 27

-“cylindrically symmetrical”
-freely rotate
-all SINGLE covalent bonds

Question 28

pi bonds

Answer 28

-double (sigma + pi) & triple (sigma + 2p)
-contain a nodal plane (prob.=0)
-two lobes (dumbbell shaped)
-locks in place, no rotation (sandwiches)
-symmetrical over a mirror plane

Question 29

sigma bonds are formed by

Answer 29

• s to s
• s to p
• s-hybrid
• p-hybrid
• px-px (p bonds along the x axis)

Question 30

pi bonds are formed by

Answer 30

• py to py (vertical y-axis)
• pz to pz (3D axis)

Question 31

hybrid orbitals belong to…

Answer 31

the atom, not the molecule

Question 32

each central atom has…

Answer 32

its own hybridization

Question 33

if an atom is bonded to more than 1 atom…

Answer 33

it NEEDS to be hybridized

Question 34

sigma bonds can be formed by…

Answer 34

s, p, or hybrid orbitals

Question 35

hybrid orbitals form…

Answer 35

sigma bonds

Question 36

pi bonds can only be formed by…

Answer 36

p orbitals