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AP Chemistry
Term 3, 2017
Bonding and Molecular Geometry Exam
Name
Date
Exam: Unit 6 Multiple Choice Bonding
AP Chemistry
Chemist: _____________________________________
Date: ___________________
Select the most appropriate response for the following prompts:
____ 1. What type of bonding is present in (NH4)2SO4?
A. Ionic Only
B. Covalent Only
C. Metallic and Covalent
D. Ionic and Covalent
____ 2. A set of terms and definitions is given below:
W. Ionic bond
1. Attraction between two different elements for each other due to
very large difference in electronegativities
X. Polar bond
2. Formed from unequal sharing of electrons within a molecule
Y. Covalent bond
3. Tendency of a neutral atom to attract electrons
Z. Electronegativity
4. Mutual sharing of two or more electrons by nuclei of different atoms
The correct sequence that matches the terms in order of W, X, Y, Z is:
A) 1, 2, 3, 4
B) 1, 2, 4, 3
C) 1, 4, 3, 2
D) 1, 4, 2, 3
____ 3. Listed below are several ionic compounds. Which of the following compounds will have the same
Lewis Dot structure as that provided?
A.
B.
C.
D.
Calcium chloride
Aluminum sulfide
Potassium phosphide
Zinc nitride
____ 4. Which of the following best describes the hybridization and VSEPR geometry for SCl2?
A. sp, linear, 180 bond angle
B. sp2, bent, less than 120 bond angle
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C. sp , bent, less than 109 bond angle
D. sp3, linear, 180 bond angle
____ 5. Which of the following molecules contains a bond order of 1.5?
A. N2
B. O3
C. NH3
D. CO
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Refer to the structures below for questions 6-10:
____ 6. Which of the structures above has/have a bond order of 1?
A. A, B, C, and D
B. C and D only
C. A and B only
D. E only
____ 7. Based on the structures above, which has/have no overall dipole?
A. A, B, and E
B. C and D only
C. A, B, C, and E
D. D only
____ 8. Of the structures shown above, which has an electron pair (Lewis Dot) geometry that is based on
an octahedral shape?
A. B only
B. C only
C. B and C
D. A only
___ 9. In which of the structures above does the central atom have a VSEPR (Molecular) Geometry of
“tetrahedral”?
A. A only
B. A and D only
C. A, C, and D only
D. A, C, D, and E
____ 10. These structures have a hybridization of sp3.
A. A, D, and E
B. D only
C. A and D only
D. A and E only
--------------------------------------------------------------------------------------------------------------------------------------____ 11. Which of the following bonds would you expect to be the MOST polar, based on the periodic table?
A. I – Cl
B. I – Br
C. I – S
D. I – I
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Refer to the Lewis structure below for questions 12-15:
____ 12. What is the bond angle that corresponds to the geometry associated with C1 in the structure?
A. 120o
B. 90o
C. 180p
D. 109.5o
____ 13. Between which bonded elements in the above structure is there the strongest dipole moment?
A. Carbon to Carbon
B. Hydrogen to Carbon
C. Oxygen to Carbon
D. Oxygen to Hydrogen
____ 14. What is the geometry associated with the C2 molecule in the structure?
A. linear
B. trigonal planar
C. bent
D. tetrahedral
____ 15. Among the choices below, which correctly describes the bonding taking place in the above structure?
A. 6 sigma bonds, 1 pi bond
B. 7 sigma bonds, 1 pi bond
C. 6 sigma bonds, 2 pi bonds
D. 7 sigma bonds, 2 pi bonds
____ 16. Of the compounds listed, which would have the strongest lattice energy?
A. NaCl
B. K2S
C. MgO
D. SrBr2
____ 17. Based on the Lewis dot structure below, which bond would be the shortest?
A. Carbon to Hydrogen
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B. Carbon to Carbon
C. Carbon to Nitrogen
D. Nitrogen to Oxygen
Refer to the Lewis Dot structures below, which represents dinitrogen monoxide, for the next two
questions.
____ 18. What is the formal charge associated with the central atom in the Lewis dot structure on the left?
A. +1
B. -1
C. 4
D. 5
____ 19. Based on formal charges of atoms, which of the two Lewis structures is more plausible?
A. The structure on the left
B. The structure on the right
C. Both are equally likely
D. Impossible to determine
Refer to the bond length diagrams below for Questions 20-21.
___ 20. What explains the substantial decrease in energy seen in both bond length diagrams above?
A. The atomic nuclei are at a distance from each other such that there is no attraction.
B. The atomic nuclei experience maximum attraction with minimum repulsion.
C. The atomic nuclei experience maximum repulsion with minimum attraction.
D. The atomic nuclei are at a distance from each other such that there is no repulsion.
____ 21. Which statement correctly identifies and rationalizes a correct difference between the two diagrams?
A. Diagram A represents a single bond because there is a shorter distance between bonded atoms.
B. Diagram A represents a double bond because there is a greater bond energy.
C. Diagram B represents a double bond because there is a longer distance between bonded atoms.
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D. Diagram B represents a single bond because there is a greater bond energy
_______22. Which of the following statements is true?
a. The breaking of bonds is exothermic, and therefore has a negative ΔH value.
b. The breaking of bonds is exothermic, and therefore has a positive ΔH value.
c. The breaking of bonds is endothermic, and therefore has a negative ΔH value.
d. The breaking of bonds is endothermic, and therefore has a positive ΔH value.
Consider the table below:
Bond
Br − Br
X−X
Average Bond Length (pm)
228
267
Average Bond Energy
(kJ/mole)
193
151
_______23.
Which atoms are represented by X-X?
a.
O-O
b.
F-F
c.
Cl-Cl
d.
I-I
_______24.
Predict which of the bonds below would be the strongest.
a. N −N
b. N = N
c. N ≡ N
d. All bonds would be the same strength.
_______25. Which statement below correctly explains why carbon and fluorine atoms form a stronger
bond than carbon and bromine atoms?
a. Fluorine atoms are smaller than bromine atoms.
b. Fluorine atoms are more electronegative than bromine atoms.
c. Fluorine atoms have fewer protons than bromine atoms.
d. Fluorine atoms form a higher order bond with carbon than bromine atoms.
_______26.
The carbonate ion has three possible equivalent Lewis structures.
What is the bond order for this ion?
a. 1
6
b. 1.3
c. 1.5
d. 2
_______27. Consider the lattice energy of any ionic compound. What combination of ions and
charges will produce the largest (in magnitude) lattice energies?
a. Small ions and small charges
b. Small ions and large charges
c. Large ions and small charges
d. Large ions and large charges
_______28. Which of the following reactions would represent the reaction with the energy change
equal to the entire lattice energy of the product?
a. Na (s) + ½ Cl2 (g)  NaCl (s)
b. 2Na (s) + Cl2 (g)  2 NaCl (s)
c. Na (g) + Cl (g)  NaCl (s)
d. Na1+ (g) + Cl1-(g)  NaCl (s)
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Exam: Unit 6 Free Response Bonding
Chemist: _____________________________________
Date: ___________________
1. The following questions refer to the bonding associated with the thiocyanate ion:
a.
Draw a possible Lewis Dot Structure for the thiocyanate ion (SCN1-).
b.
Draw a possible resonance structure for the thiocyanate ion.
c.
What are the molecular (VSEPR) geometry for the thiocyanate ion?
d.
Of the two Lewis Dot structures drawn, which structure would be most favorable in terms of formal
charge. Show work to justify your answer.
2.
GeCl4
SeCl4
ICl4+
ICl4The species represented above all have the same number of chlorine atoms attached to the central atom.
(a) Draw the Lewis structure (electron-dot diagram) of each of the four species. Show all valence
electrons in your structures.
(b) On the basis of the Lewis structures drawn in part (a), answer the following questions about the
particular species indicated.
i. What is the Cl – Ge – Cl bond angle in GeCl4?
_______________
ii. Is SeCl4 polar? Explain.
iii. What is the hybridization of the I atom in ICl4-?
iv. What is the geometric shape formed by the atoms in
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_______________
ICl4+?
_______________________
3.
Answer the following questions regarding the organic molecule ethyl amine (C2H7N).
a. Complete the Lewis structure above by adding in appropriate covalent bonds and pairs of electrons,
where appropriate.
b. What is the molecular geometry around the first carbon in the chain, C ? ______________________
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c. Based on the chemical structure and molecular geometry, would the molecule be expected to be
polar or nonpolar overall? Explain.
4.
Provided the following reaction equation, respond to the corresponding prompts.
____ O2 (g) + ____ H2S (g) → ____ H2O (l) + ____ SO2 (g)
a.
b.
Balance the reaction equation above.
Using the below table of bond energies, determine the heat of the reaction.
Bond
Bond Energy
Bond
Bond Energy
O-O
146 kJ/mol
S=O
523 kJ/mol
O=O
495 kJ/mol
H-O
467 kJ/mol
S-O
265 kJ/mol
H-S
347 kJ/mol
c.
Based on the overall enthalpy of reaction, discuss why the reaction is either endothermic or
exothermic based its relationship to bonds being formed and broken. Provide a thorough
explanation for your response.
d.
If 35.0 g of hydrogen sulfide reacted, how much heat would have been involved in the reaction?
Use an appropriate sign to signify whether energy is being absorbed or released.
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