Chapter 6

Question 1

How is a molecule polar?

Answer 1

when two atoms have different electronegativities, this creates a polar bond

Question 2

Dipole moments

Answer 2

the extent to which the molecules align in an electric field

Question 3

Bond length

Answer 3

the internuclear separation distance where the molecule is most stable

Question 4

Bond energy

Answer 4

the stability of a chemical bond, energy required to break the bond

Question 5

How is a molecule non-polar?

Answer 5

The molecular symmetry cancel out the vectors.

Question 6

How many ligands and lone pairs are in the following molecules? What about their steric number?

a) CH4
b) NH3
c) H20

Answer 6

ligands lone pairs

a) 4 0
b) 3 1
c) 2 2

steric number is all the same = 4

Question 7

Draw the Lewis structure for HCN.

Answer 7

see cahier

Question 8

Draw the Lewis structure for ketene, C2H2O

Answer 8

see cahier

Question 9

Draw the Lewis structure for ClBr3, identify if its polar or non-polar, the approximate bond angles, and its molecular geometry.

Answer 9

see cahier
polar
90 degrees, 180 degrees
t-shaped

Question 10

Draw the Lewis structure for ClF4-

Answer 10

see cahier

Question 11

Draw the resonance structures for NO3-

Answer 11

see cahier

Question 12

Arrange the following set of bonds according to length, from longest to shortest. N triple bonded to N , N=N,
N-N

Answer 12

N-N , N=N, N triple bonded to N

Question 13

What are the bond angles for the following:

a) O-S-O angle of SO2
b) O-S-O angle of SO3
c) F-O-F angle of OF2
d) O-C-O angle of CO2
e) F-P-F angle of PF3
f) Cl-Si-Cl angle of SiCl4

Answer 13

a) 120
b) 120
c) 109.5
d) 180
e) 109.5
f) 109.5

Question 14

Predict the approximate bond angles of the following molecules:

a) CH3
b) SiCl4

Answer 14

a) 120

b) 109.5

Question 15

Which of these are polar?

a) SO2
b) CO2
c) CH2Cl2
d) PCl3

Answer 15

a) SO2
c) CH2Cl2
d) PCl3

Question 16

Draw the Lewis structure for BF3, show all lone pairs, optimize formal charges, but do not show them.

Answer 16

see cahier

Question 17

Draw the Lewis structure for ICl2+, show all lone pairs, optimize formal charges, but do not show them.

Answer 17

see cahier

Question 18

Draw the Lewis structure for NO2-, show all lone pairs, optimize formal charges, but do not show them.

Answer 18

see cahier

Question 19

Draw the Lewis structure for CH3CH2CO2-, show all lone pairs, optimize formal charges, but do not show them.

Answer 19

see cahier

Question 20

Draw the Lewis structure for SbCl5, show all lone pairs, optimize formal charges, but do not show them.

Answer 20

see cahier

Question 21

Consider the following:
CO2, SO2, NO2-
Which of the statements is correct?
a) all three have a trigonal planar electron group geometry
b) all three are polar
c) NO2- is the only polar one
d) SO2 and NO2- are the only polar ones
e) CO2 and SO2 are polar while NO2- is non polar

Answer 21

d) SO2 and NO2- are the only polar ones

Question 22

What is the arrangement of the bonds surrounding a carbon atom in an alkene?

a) linear
b) tetrahedral
c) trigonal planar
d) trigonal bipyramidal
e) octahedral

Answer 22

b) tetrahedral

Question 23

Based on the VSPER Theory the ClF3 molecule is:

a) T-shaped
b) seesaw shaped
c) trigonal bipyramidal
d) linear
e) has 3 lone pairs

Answer 23

a) T-shaped

* always assume molecular shape if not specified*

Question 24

According to the Lewis Theory, what are the formal charges on the atoms of HOOH?

Answer 24

HOOH

0 0 0 0

Question 25

Despite many attempts the perbromate ion (BrO4-) was not prepared in the laboratory until about 1970. What is the formal charge on the bromine atom in this ion?

Answer 25

0

Question 26

What is the molecular shape of IF5? a) square pyramidal b) tetrahedral c) seesaw d) trigonal bipyramidal e) octahedral

Answer 26

a) square pyramidal

Question 27

What are the ideal bond angles in SF4? a) 109.5 b) <120 c) <90 and<120 d) >120 and >90 e) 120 and 90

Answer 27

c) <90 and <120

Question 28

Draw the best lewis structure for IBrCl-

Answer 28

see binder

Question 29

Draw the best lewis structure for GaI3

Answer 29

see binder