Chemistry 101
Section 219
Fall 2007
Quiz #6
VERSION B
November 16, 2007
Required: Scantron form 882-E
Instructions:
Do not open this quiz until instructed to do so.
(1) Write your name on your Scantron Form
(2) Write Version B in the box for “Test No.”
(3) Answer all questions on your Scantron Form
(4) When instructed to do so, check to ensure that your quiz has 20
multiple choice questions
You may write on this test, but only the Scantron Form will be scored!
Answer the questions on your Scantron form. Each question is worth 2 points.
Maximum Score: 40 points
MULTIPLE CHOICE. Choose the one alternative that best completes the
statement or answers the question.
1) Choose the bond below that is most polar based on periodic trends.
A) C-F
B) F-F
C) C-C
D) C-N
E) C-O
2) If a central atom is surrounded by one double bond, three single bonds, and one lone
pair, what is the molecular geometry around that atom?
A) Tetrahedral
B) Seesaw
C) Trigonal Bipyramidal
D) Square Pyramidal
E) Trigonal Pyramidal
3) Use the bond energies provided to estimate ΔH°rxn for the reaction below.−
PCl3(g) + Cl2(g) → PCl5(l) ΔH°rxn= ?
Bond Bond Energy (kJ/mol)
Cl-Cl 243
P-Cl 331
A) -905 kJ
B) -662 kJ
C) -67 kJ
D) -419 kJ
E) -243 kJ
4) Which of the following reactions represent the lattice energy of CaS (ΔH°latt)?
A) CaS(s) → Ca2⁺(aq) + S2–(aq)
B) Ca2⁺(aq) + S2–(aq) → CaS(s)
C) Ca(s) + S(s) → CaS(s)
D) CaS(s) → Ca(s) + S(s)
E) Ca2⁺(g) + S2–(g) → CaS(s)
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5) Which of the following statements is FALSE?
A) The enthalpy of formation of an ionic compound can be described by its lattice
energy
B) Breaking bonds is an endothermic process.
C) Ionic compounds form crystal lattices.
D) Both A and B are false
E) None of the above.
6) There are three possible Lewis structures for the thiocyanate ion. The BEST Lewis
structure will have what formal charge on the nitrogen atom?
A) 0
B) 1
C) 2
D) –1
E) –2
7) The Lewis dot structure for CO32– has how many equivalent resonance structures?
A) 0
B) 1
C) 2
D) 3
E) 4
8) The Lewis dot structure of N2H2 shows ___________________. Hint:This molecule
has two central atoms.
A) A nitrogen–nitrogen single bond
B) A nitrogen-nitrogen triple bond
C) Each nitrogen atom has one lone pair of electrons
D) Each nitrogen atom has two lone pairs of electrons
E) Each hydrogen atom has one lone pair of electrons
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9) Consider a molecule with the following connections:
O O
H O C C O H
When a valid Lewis dot structure is written, how many double bonds will the molecule
contain?
A) 0
B) 1
C) 2
D) 3
E) 4
10) Which of the following compounds has the shortest carbon-carbon bond?
A)
B)
C)
D)
E)
HCCH
H2CCH2
H3CCH3
H3CCF3
F3CCF3
11) Which element can expand its valence shell to accommodate more than eight
electrons?
A) C
B) O
C) S
D) He
E) Both B and C
12) Draw the best Lewis structure for the free radical, NO2. What is the formal charge on
the N?
A) +1
B) -1
C) -2
D) +2
E) 0
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13) Choose the best Lewis structure for ICl5.
A)
B)
C)
D)
E)
14) Draw the Lewis formula for IF2+. How many lone pair(s) of electrons are there in the
valence shell of the central atom?
A) 0
B) 1
C) 2
D) 3
E) 4
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15) Which of the following does not follow the octet rule?
A) CO
B) BH3
C) CO2
D) CH4
E) SO3
16) Choose the best Lewis structure for PO43⁻–
A)
B)
C)
D)
E)
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17) What are the bond angles in the following molecular model of BCl3?
A) 90°
B) 109.5°
C) 120°
D) 180°
E) 60°
18) Which of the following statements is TRUE?
A) An atom with octahedral geometry will have approximate bond angles of 109.5°
B) If an atom with two lone pairs has tetrahedral electron geometry, it has a linear
molecular geometry.
C) If an atom with one set of lone pairs has tetrahedral electron geometry, it has a Tshaped molecular geometry.
D) The seesaw geometry derives from a molecule with trigonal bipyrimadal geometry, in
which the lone pair of electrons occupies the axial position.
E) None of the above are true.
19) What is the geometry around the central atom in the following molecular model?
A)
B)
C)
D)
E)
Trigonal Bipyramidal
Square Planar
Square Pyramidal
Tetrahedral
Seesaw
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20) A molecule with the formula AB3 has trigonal pyramidal geometry. How many
electron groups are on the central atom (A)?
A) 1
B) 2
C) 3
D) 4
E) 5
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