PE3b.pdf

CHM 111 Exam 3 Name___________________________________
Do not remove staple
Periodic Table on Back Multiple Choice (50%)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Two resonance forms for SOCl2 are given below.
Which is favored by the octet rule and which by formal charge considerations?
A) I is favored by the octet rule and II by formal charge considerations.
B) I is favored by the octet rule and by formal charge considerations.
C) II is favored by the octet rule and by formal charge considerations.
D) II is favored by the octet rule and I by formal charge considerations.
2) Which type of bond produces a charge cloud with a nodal plane containing the bond axis?
A) σ B) π C) σ and π D) neither σ nor π
3) What is the geometry around the central atom in the following molecular model of SCl 4?
A) trigonal bipyramidal B) seesaw
C) T-shaped D) linear
4) Which element can expand its valence shell to accommodate more than eight electrons?
A) C B) O C) He D) P
5) What orbital hybridization is expected for the central atom in a molecule with a square planar
geometry?
A) sp3d2 B) sp3 C) sp3d D) sp2
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6) A triple bond is generally composed of
A) three π bonds. B) three σ bonds.
C) one π bond and two σ bonds. D) two π bonds and one σ bond.
7) Which of the following would be expected to have sp2 hybridization on atom A?
A) I and IV B) II C) I and III D) I, II, and III
8) How many lone pairs of electrons are on the P atom in PF3?
A) 2 B) 1 C) 0 D) 3
9) Of the following elements, which has the lowest electronegativity?
A) Mg B) Br C) Ca D) Cl
10) What is the geometry around the central atom in the following molecular model of PF 6 -?
A) trigonal bipyramidal B) octahedral
C) square pyramidal D) square planar
11) Which one of the following is expected to exhibit resonance?
A) CO2 B) HCN C) NO2- D) NH4 +
12) What is the molecular geometry of AsCl3?
A) T-shaped B) trigonal planar
C) tetrahedral D) trigonal pyramidal
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13) Which bond should have the longest length?
A) N=N
B) NN
C) NN
D) All three bond lengths should be about the same.
14) What is the molecular geometry of IF5?
A) trigonal bipyramidal B) seesaw
C) octahedral D) square pyramidal
15) Covalent bonding is a
A) loss of electrons. B) transfer of electrons.
C) gain of electrons. D) sharing of electrons.
16) Which is the most acceptable electron dot structure for carbonyl fluoride, COF2?
A) B)
C) D)
17) Which orbital hybridization is associated with a tetrahedral charge cloud arrangement?
A) sp2 B) sp3d2 C) sp3 D) sp
18) What is the geometry around the central atom in the following molecular model of PH3?
A) linear B) bent
C) trigonal pyramidal D) tetrahedral
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19) Which bond should have the highest bond dissociation energy?
A) NN
B) NN
C) NN
D) All three bonds should have about the same dissociation energy.
20) Based on the indicated electronegativities, arrange the following in order of increasing ionic
character: CsBr, LaBr3, PBr3, MgBr2.
Element Electronegativity
Br 2.8
P 2.1
Mg 1.2
La 1.0
Cs 0.7
A) PBr3, LaBr3, MgBr2, CsBr B) CsBr, MgBr2, PBr3, LaBr3
C) PBr3, MgBr2, LaBr3, CsBr D) CsBr, LaBr3, MgBr2, PBr3
21) The electronegativity for both sulfur and carbon is 2.5. Therefore the compound CS 2 would be
expected to
A) be ionic with C as the cation.
B) have polar covalent bonds between C and S.
C) be ionic with C as the anion.
D) have nonpolar covalent bonds between C and S.
22) In the best Lewis structure for NO+, what is the formal charge on the N atom?
A) 0 B) -1 C) +1 D) +2
23) Assign formal charges to each atom in the resonance form for SOCl2 given below.
A) -1 for Cl, -2 for S, and -2 for O B) -1 for Cl, +4 for S, and -2 for O
C) 0 for Cl, 0 for S, and 0 for O D) 0 for Cl, +1 for S, and -1 for O
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24) What is the geometry around the central atom in the following molecular model of CCl 4?
A) linear B) bent
C) trigonal pyramidal D) tetrahedral
25) Based on VSEPR theory, which should have the smallest XAX bond angle?
A) B) C) D)
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CHM 111 Exam 3 Molecular Structure (50%)
1. In the space below, draw all of the acceptable Lewis Structures for POF3 where P is the
only central atom.
2. Circle the most favored resonance form (or forms).
3. Name the shape of POF3
4. Give the hybridization for the P atom
5. Which bond, if any, do you expect to be shortest? Explain.
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CHM 111 Exam 3 Name___________________________________
Do not remove staple
Periodic Table on Back Multiple Choice (50%)
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Two resonance forms for SOCl2 are given below.
Which is favored by the octet rule and which by formal charge considerations?
A) I is favored by the octet rule and II by formal charge considerations.
B) I is favored by the octet rule and by formal charge considerations.
C) II is favored by the octet rule and by formal charge considerations.
D) II is favored by the octet rule and I by formal charge considerations.
2) Which type of bond produces a charge cloud with a nodal plane containing the bond axis?
A) σ B) π C) σ and π D) neither σ nor π
3) What is the geometry around the central atom in the following molecular model of SCl 4?
A) trigonal bipyramidal B) seesaw
C) T-shaped D) linear
4) Which element can expand its valence shell to accommodate more than eight electrons?
A) C B) O C) He D) P
5) What orbital hybridization is expected for the central atom in a molecule with a square planar
geometry?
A) sp3d2 B) sp3 C) sp3d D) sp2
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2)
3)
4)
5)

6) A triple bond is generally composed of
A) three π bonds. B) three σ bonds.
C) one π bond and two σ bonds. D) two π bonds and one σ bond.
7) Which of the following would be expected to have sp2 hybridization on atom A?
A) I and IV B) II C) I and III D) I, II, and III
8) How many lone pairs of electrons are on the P atom in PF3?
A) 2 B) 1 C) 0 D) 3
9) Of the following elements, which has the lowest electronegativity?
A) Mg B) Br C) Ca D) Cl
10) What is the geometry around the central atom in the following molecular model of PF 6 -?
A) trigonal bipyramidal B) octahedral
C) square pyramidal D) square planar
11) Which one of the following is expected to exhibit resonance?
A) CO2 B) HCN C) NO2- D) NH4 +
12) What is the molecular geometry of AsCl3?
A) T-shaped B) trigonal planar
C) tetrahedral D) trigonal pyramidal
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13) Which bond should have the longest length?
A) N=N
B) NN
C) NN
D) All three bond lengths should be about the same.
14) What is the molecular geometry of IF5?
A) trigonal bipyramidal B) seesaw
C) octahedral D) square pyramidal
15) Covalent bonding is a
A) loss of electrons. B) transfer of electrons.
C) gain of electrons. D) sharing of electrons.
16) Which is the most acceptable electron dot structure for carbonyl fluoride, COF2?
A) B)
C) D)
17) Which orbital hybridization is associated with a tetrahedral charge cloud arrangement?
A) sp2 B) sp3d2 C) sp3 D) sp
18) What is the geometry around the central atom in the following molecular model of PH3?
A) linear B) bent
C) trigonal pyramidal D) tetrahedral
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19) Which bond should have the highest bond dissociation energy?
A) NN
B) NN
C) NN
D) All three bonds should have about the same dissociation energy.
20) Based on the indicated electronegativities, arrange the following in order of increasing ionic
character: CsBr, LaBr3, PBr3, MgBr2.
Element Electronegativity
Br 2.8
P 2.1
Mg 1.2
La 1.0
Cs 0.7
A) PBr3, LaBr3, MgBr2, CsBr B) CsBr, MgBr2, PBr3, LaBr3
C) PBr3, MgBr2, LaBr3, CsBr D) CsBr, LaBr3, MgBr2, PBr3
21) The electronegativity for both sulfur and carbon is 2.5. Therefore the compound CS 2 would be
expected to
A) be ionic with C as the cation.
B) have polar covalent bonds between C and S.
C) be ionic with C as the anion.
D) have nonpolar covalent bonds between C and S.
22) In the best Lewis structure for NO+, what is the formal charge on the N atom?
A) 0 B) -1 C) +1 D) +2
23) Assign formal charges to each atom in the resonance form for SOCl2 given below.
A) -1 for Cl, -2 for S, and -2 for O B) -1 for Cl, +4 for S, and -2 for O
C) 0 for Cl, 0 for S, and 0 for O D) 0 for Cl, +1 for S, and -1 for O
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24) What is the geometry around the central atom in the following molecular model of CCl 4?
A) linear B) bent
C) trigonal pyramidal D) tetrahedral
25) Based on VSEPR theory, which should have the smallest XAX bond angle?
A) B) C) D)
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CHM 111 Exam 3 Molecular Structure (50%)
1. In the space below, draw all of the acceptable Lewis Structures for POF3 where P is the
only central atom.
2. Circle the most favored resonance form (or forms).
3. Name the shape of POF3
4. Give the hybridization for the P atom
5. Which bond, if any, do you expect to be shortest? Explain.
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