Name: Class: Date: 3) The bond angles marked a, b, and c in the molecule below are about,, and, respectively.

Unit 9 Practice

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____ 1) The basis of the VSEPR model of molecular bonding is ____.

A) regions of electron density on an atom will organize themselves so as to maximize s-character

B) regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap

C) atomic orbitals of the bonding atoms must overlap for a bond to form

D) electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions

E) hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry

____ 2) The electron-domain geometry of ____ is tetrahedral.

A) CBr

B) PH

C) CCl

Br

D) XeF

E) all of the above except XeF

____ 3) The bond angles marked a, b, and c in the molecule below are about ____, ____, and ____, respectively.

A) 109.5°, 109.5°, 109.5°

B) 120°, 109.5°, 120°

C) 109.5°, 109.5°, 120°

D) 90°, 180°, 90°

E) 109.5°, 109.5°, 90°

____ 4) A molecule has the formula AB3 and the central atom is in a different plane from the surrounding three atoms.

Its molecular shape is ____.

A) tetrahedral

B) trigonal pyramidal C) linear

D) T-shaped

E) bent

Name: ________________________ ID: A

____ 5) Three monosulfur fluorides are observed: SF

, SF

, and SF

. Of these, ____ is/are polar.

A) SF

only

B) SF

and SF

only C) SF

only

D) SF

only

E) SF

, SF

, and SF

____ 6) The molecular geometry of the BCl

molecule is ____, and this molecule is ____.

A) trigonal pyramidal, polar B) trigonal pyramidal, nonpolar C) trigonal planar, polar D) trigonal planar, nonpolar E) trigonal bipyramidal, polar

____ 7) The hybridizations of iodine in IF

and IF

are ____ and ____, respectively.

A) sp

, sp

d B) sp

d, sp

d

C) sp

d, sp

D) sp

d

, sp

d E) sp

d

, sp

d

____ 8) The electron-domain geometry of the AsF

molecule is trigonal bipyramidal. The hybrid orbitals used by the As atom for bonding are ____ orbitals.

A) sp

d

B) sp

C) sp

d

D) sp

d E) sp

____ 9) A typical double bond ____.

A) is stronger and shorter than a single bond B) consists of one  bond and one  bond C) imparts rigidity to a molecule

D) consists of two shared electron pairs E) All of the above answers are correct.

____ 10) Which of the following molecules or ions will exhibit delocalized bonding?

SO

SO

SO

A) SO

, SO

, and SO

B) SO

only

C) SO

and SO

D) SO

and SO

E) None of the above will exhibit delocalized bonding.

____ 11) The hybridization of the terminal carbons in the H

C C CH

molecule is ____.

A) sp

B) sp

C) sp

D) sp

d

____ 12) The bond order of any molecule containing equal numbers of bonding and antibonding electrons is ____.

A) 0 B) 1 C) 2 D) 3 E) 1/2

____ 13) Based on molecular orbital theory, the bond order of the H—H bond in the H

+ ion is ____.

A) 0 B) 1/2 C) 1 D) 3/2 E) 2

____ 14) Molecular Orbital theory correctly predicts paramagnetism of oxygen gas, O

. This is because ____.

A) the bond order in O

can be shown to be equal to 2.

B) there are more electrons in the bonding orbitals than in the antibonding orbitals.

C) the energy of the 

MOs is higher than that of the 

MO

D) there are two unpaired electrons in the MO electron configuration of O

E) the O—O bond distance is relatively short

____ 15) Of the following, only ____ appears to gain mass in a magnetic field.

A) C

B) N

C) F

D) O

E) Li

____ 16) The bond order of a homonuclear diatomic molecule can be decreased by ____.

A) removing electrons from a bonding MO or adding electrons to an antibonding MO B) adding electrons to a bonding MO or removing electrons from an antibonding MO C) adding electrons to any MO

D) removing electrons from any MO

E) The bond order of a homonuclear diatomic molecule cannot be decreased by any means.

____ 17) For a molecule with the formula AB

, the molecular shape is ____.

A) linear or bent

B) linear or trigonal planar C) linear or T-shaped D) T-shaped

E) trigonal planar

____ 18) The molecular geometry of the SiH

Cl

molecule is ____.

A) trigonal planar B) tetrahedral

C) trigonal pyramidal D) octahedral

E) T-shaped

Name: ________________________ ID: A

____ 19) The O-S-O bond angle in SO

is slightly less than ____.

A) 90°

B) 109.5°

C) 120°

D) 180°

E) 60°

____ 20) The hybridization of orbitals on the central atom in a molecule is sp. The electron-domain geometry around this central atom is ____.

A) octahedral B) linear

C) trigonal planar D) trigonal bipyramidal E) tetrahedral

____ 21) The electron-domain geometry of the AsF

- ion is octahedral. The hybrid orbitals used by the As atom for bonding are ____ orbitals.

A) sp

d

B) sp

C) sp

d D) sp

d

E) sp

____ 22) There are ____  and ____  bonds in the H—CC—H molecule.

A) 3 and 2 B) 3 and 4 C) 4 and 3 D) 2 and 3 E) 5 and 0

____ 23) There is/are ____  bond(s) in the molecule below.

A) 7

B) 6

C) 2

D) 1

E) 0

____ 24) The central atom in the ICl

- ion has ____ nonbonded electron pair(s) and ____ bonded electron pair(s) in its valence shell.

A) 4, 2 B) 0, 4 C) 2, 4 D) 2, 2 E) 6, 0

____ 25) The electron-domain geometry and molecular geometry of the nitrite ion are ____ and ____, respectively.

A) trigonal bipyramidal, trigonal planar B) tetrahedral, trigonal pyramidal C) trigonal bipyramidal,T-shaped D) trigonal planar, bent

E) T-shaped, trigonal planar

____ 26) Using the VSEPR model, the molecular geometry of the central atom in SO

is ____.

A) linear

B) trigonal planar C) tetrahedral D) bent

E) trigonal pyramidal

____ 27) Of the molecules below, only ____ is polar.

A) CO

B) CH

C) PF

D) SnF

E) H

____ 28) According to valence bond theory, which orbitals overlap in the formation of the bond in Br

? A) 3s

B) 3p C) 4s D) 4p E) 3d

____ 29) There is/are ____ hybridized s atomic orbital(s) in an sp-hybridized carbon atom.

A) 4 B) 0 C) 3 D) 1 E) 2

____ 30) Based on molecular orbital theory, the bond order of the N—N bond in the N

molecule is ____.

A) 0

B) 1/2

C) 3

D) 2

E) 1

Name: ________________________ ID: A

____ 31) In molecular orbital theory, the bond order of the He—He bond in He

is ____.

A) 0 B) 2 C) He—He D) 1 E) 1/2

Short Answer

1) What is the molecular geometry of a molecule that has three bonding and two non-bonding domains?

2) In the valence shell of an atom there are six electron domains. They will be arranged in a(n) ________

geometry.

3) What are the three bond angles in the trigonal bipyramidal structure?

4) Three molecules have similar electron domains, but different molecular shapes. Why?

5) The 1s hydrogen orbital overlaps with the ________ iodine orbital in HI.

6) A covalent bond in which overlap regions lie above and below an internuclear axis is called a(n) ________.

7) The sensation of vision results from a nerve impulse that is triggered by the separation of retinal from ________.

8) In molecular orbital theory, the stability of a covalent body is related to its ________.

9) Each molecular orbital can accommodate, at most, two electrons with their spins paired. This is called the ________.

10) The more unpaired electrons in a species, the stronger is the force of magnetic attraction. This is called ________.

True/False

Indicate whether the statement is true or false.

____ 1) Possible shapes of AB

molecules are linear, trigonal planar, and T-shaped.

____ 2) Boron trifluoride has three bonding domains, and its electron domain geometry is trigonal planar.

____ 3) Electron domains for single bonds exert greater force on adjacent domains than the electron domains for multiple bonds.

____ 4) The quantitative amount of charge separation in a diatomic molecule contributes to the dipole moment of that

molecule.

____ 5) XeF

is a polar molecule.

____ 6) Hybridization is the process of mixing atomic orbitals as atoms approach each other to form a bond.

____ 7) Electrons in core orbitals contribute to atom bonding.

____ 8) Nitrogen is colorless because the minimum energy to excite an electron is in the ultraviolet section of the

spectrum.

ID: A

Unit 9 Practice Answer Section

MULTIPLE CHOICE

1) ANS: D PTS: 1 DIF: 1 REF: Page Ref: 9.2

OBJ: 9.2; G2

2) ANS: E PTS: 1 DIF: 2 REF: Page Ref: 9.2

OBJ: 9.2; G2

3) ANS: C PTS: 1 DIF: 2 REF: Page Ref: 9.2

OBJ: 9.2; G2

4) ANS: B PTS: 1 DIF: 2 REF: Page Ref: 9.2

OBJ: 9.2; G2

5) ANS: B PTS: 1 DIF: 2 REF: Page Ref: 9.3

OBJ: 9.3; G2

6) ANS: D PTS: 1 DIF: 1 REF: Page Ref: 9.3

OBJ: 9.3; G2

7) ANS: B PTS: 1 DIF: 1 REF: Page Ref: 9.5

OBJ: 9.5; G2

8) ANS: D PTS: 1 DIF: 1 REF: Page Ref: 9.5

OBJ: 9.5; G2

9) ANS: E PTS: 1 DIF: 1 REF: Page Ref: 9.6

OBJ: 9.6; G2

10) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 9.6

OBJ: 9.6; G2

11) ANS: B PTS: 1 DIF: 2 REF: Page Ref: 9.6

OBJ: 9.6; G2

12) ANS: A PTS: 1 DIF: 3 REF: Page Ref: 9.7

OBJ: 9.7; G2

13) ANS: B PTS: 1 DIF: 4 REF: Page Ref: 9.7

OBJ: 9.7; G2

14) ANS: D PTS: 1 DIF: 4 REF: Page Ref: 9.7-9.8

OBJ: 9.7, 9.8; G2

15) ANS: D PTS: 1 DIF: 4 REF: Page Ref: 9.8

OBJ: 9.8; G2

16) ANS: A PTS: 1 DIF: 4 REF: Page Ref: 9.8

OBJ: 9.8; G2

17) ANS: A PTS: 1 DIF: 1 REF: Page Ref: 9.1

OBJ: 9.2; G2

18) ANS: B PTS: 1 DIF: 1 REF: Page Ref: 9.2

OBJ: 9.2; G2

19) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 9.2

OBJ: 9.2; G2

20) ANS: B PTS: 1 DIF: 1 REF: Page Ref: 9.5

OBJ: 9.5; G2

22) ANS: A PTS: 1 DIF: 1 REF: Page Ref: 9.6 OBJ: 9.6; G2

23) ANS: D PTS: 1 DIF: 1 REF: Page Ref: 9.6

OBJ: 9.6; G2

24) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 9.2

OBJ: 9.2; G2

25) ANS: D PTS: 1 DIF: 1 REF: Page Ref: 9.2

OBJ: 9.2; G2

26) ANS: B PTS: 1 DIF: 1 REF: Page Ref: 9.2

OBJ: 9.2; G2

27) ANS: D PTS: 1 DIF: 2 REF: Page Ref: 9.3

OBJ: 9.3; G2

28) ANS: D PTS: 1 DIF: 1 REF: Page Ref: 9.4

OBJ: 9.4; G2

29) ANS: D PTS: 1 DIF: 1 REF: Page Ref: 9.5

OBJ: 9.5; G2

30) ANS: C PTS: 1 DIF: 4 REF: Page Ref: 9.8

OBJ: 9.7, 9.8; G2

31) ANS: C PTS: 1 DIF: 1 REF: Page Ref: 9.7-9.8

OBJ: 9.7, 9.8; G2

SHORT ANSWER 1) ANS:

T-shaped

PTS: 1 DIF: 4 REF: Page Ref: 9.2

OBJ: 9.2; G2 2) ANS:

octahedral

PTS: 1 DIF: 5 REF: Page Ref: 9.2

OBJ: 9.2; G2 3) ANS:

90°, 120°, 180°

PTS: 1 DIF: 4 REF: Page Ref: 9.2

OBJ: 9.2; G2 4) ANS:

different numbers of non-bonding domains

PTS: 1 DIF: 4 REF: Page Ref: 9.2

OBJ: 9.2; G2 5) ANS:

5p

PTS: 1 DIF: 2 REF: Page Ref: 9.5

ID: A 6) ANS:

 bond

PTS: 1 DIF: 2 REF: Page Ref: 9.6

OBJ: 9.6; G2 7) ANS:

opsin

PTS: 1 DIF: 2 REF: Page Ref: 9.6

OBJ: 9.6; G2 8) ANS:

bond order

PTS: 1 DIF: 2 REF: Page Ref: 9.7

OBJ: 9.7; G2 9) ANS:

Pauli principle

PTS: 1 DIF: 4 REF: Page Ref: 9.8

OBJ: 9.8; G2 10) ANS:

paramagnetism

PTS: 1 DIF: 1 REF: Page Ref: 9.8

OBJ: 9.8; G2

TRUE/FALSE

1) ANS: F PTS: 1 DIF: 2 REF: Page Ref: 9.1

OBJ: 9.2; G2

2) ANS: T PTS: 1 DIF: 2 REF: Page Ref: 9.2

OBJ: 9.2; G2

3) ANS: F PTS: 1 DIF: 1 REF: Page Ref: 9.2

OBJ: 9.2; G2

4) ANS: T PTS: 1 DIF: 1 REF: Page Ref: 9.3

OBJ: 9.3; G2

5) ANS: F PTS: 1 DIF: 3 REF: Page Ref: 9.3

OBJ: 9.3; G2

6) ANS: T PTS: 1 DIF: 1 REF: Page Ref: 9.5

OBJ: 9.5; G2

7) ANS: F PTS: 1 DIF: 1 REF: Page Ref: 9.6

OBJ: 9.6; G2

8) ANS: T PTS: 1 DIF: 3 REF: Page Ref: 9.8

OBJ: 9.8; G2

_____ 1) D

_____ 2) E

_____ 3) C

_____ 4) B

_____ 5) B

_____ 6) D

_____ 7) B

_____ 8) D

_____ 9) E

_____ 10) C

_____ 11) B

_____ 12) A

_____ 13) B

_____ 14) D

_____ 15) D

_____ 16) A

_____ 17) A

_____ 18) B

_____ 19) C

_____ 20) B

_____ 21) D

_____ 22) A

_____ 23) D

_____ 24) C

_____ 25) D

_____ 26) B

_____ 27) D

_____ 28) D

_____ 29) D

_____ 30) C

ID: A Unit 9 Practice [Answer Strip]

_____ 31) C

_____ 1) F _____ 2) T _____ 3) F

_____ 4) T

_____ 5) F

_____ 6) T

_____ 7) F

_____ 8) T