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Swamy
Fall 2013
CHM 1045
Practice Exam 3
1. All the following statements about electron dot formula for NO3- are true except
A.
B.
C.
D.
E.
It has three resonance structures
The structure has 26 electrons.
The structure has 2 single bonds and 1 double bond
The structure has four bonding electron pairs
The structure has sixteen unpaired electrons
2. The molecular geometry of the ClF3 molecule is best described as:
A.
B.
C.
D.
E.
see-saw
trigonal planar
trigonal bipyramidal
T-shaped
trigonal pyramidal
3. An atom of vanadium has ___ unpaired electrons and is _____.
A.
B.
C.
D.
E.
0, diamagnetic
2, diamagnetic
3, paramagnetic
5, paramagnetic
4, diamagnetic
4. Estimate the enthalpy change (ΔH) for the production of ethanol (C2 H5 OH) from the gas
phase hydration of ethylene (C2 H4 ) according to the following reaction
C2 H4 (g) + H2O (g) → C2 H5 OH (l)
BE(C=C) = 615 kJ/mol
BE(C-H) = 410 kJ/mol
BE(C-C) = 350 kJ/mol
BE(C-O) = 350 kJ/mol
BE(O-H) = 462 kJ/mol
A.
B.
C.
D.
E.
- 580 kJ
- 33 kJ
+ 33 kJ
+ 580 kJ
-1509 kJ
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Swamy
Fall 2013
5. Which one of the following compounds does not follow the octet rule?
A.
B.
C.
D.
E.
NF3
CO2
CF4
Br2
NO
6. According to the VSEPR theory, the F -As -F bond angles in the AsF4- ion are predicted to
be
A.
B.
C.
D.
E.
109.5°
90° and 120°
180°
< 109.5°
< 90° & < 120°
7. How many liters of oxygen gas at 153°C and 0.820 atm can be produced by the reaction of
22.4 g of KClO3?
2KClO3(s) →
A.
B.
C.
D.
E.
2KCl(s) + 3O2(g)
3.0 L
0.085 L
4.20 L
7.79 l
11.7 L
8. Which of the following gas molecules have the highest average kinetic energy at 25°C?
A.
B.
C.
D.
E.
NH3
NO2
N2O5
PCl3
All the gases have the same average kinetic energy.
9. Which of the following is the electron configuration of a sulfide ion, S2-?
A. [Ne]3s23p4
B. [Ne]
C. [Ne]3s23p1
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D. [Ar]
E. [Ne]3s23p2
Swamy
Fall 2013
10. The ground state electron configuration for an atom of Selenium is
A.
B.
C.
D.
E.
[Kr] 4s0 3d10 4p6
[Ar] 4s2 3d10 4p4
[Ar] 4s2 4d10 4p4
[Kr] 5s2 5d10 5p4
[Kr] 5s2 4d10 5p4
11. Which one of the following sets of quantum numbers is not possible?
A.
B.
C.
D.
E.
n
l
ml
ms
4
3
3
2
2
3
0
0
1
0
-2
1
0
1
0
+ 1/2
- 1/2
+ 1/2
- 1/2
+ 1/2
12. What is the hybridization of the As atom in the AsF5 molecule?
A.
B.
C.
D.
E.
sp
sp2
sp3
sp3d
sp3d2
13. According to VSEPR theory, which one of the following molecules should be a bent shape?
A.
B.
C.
D.
E.
Cl2O
CO2
HCN
CCl4
none of them
14. The Lewis structure for a chlorate ion, ClO3− should show ____ single bond(s), ____
double bond(s), and ____ lone pair(s).
A.
B.
C.
D.
E.
2, 1, 10
3, 0, 9
2, 1, 8
3, 0, 10
3, 1, 10
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Swamy
Fall 2013
15. Calculate the density of Br2(g) at 59.0°C and 1.00 atm pressure.
A.
B.
C.
D.
E.
27.2 g/L
5.86 g/L
769 g/L
22.4 g/L
3.45 g/L
16. Which gas has molecules with the lowest average molecular speed at 25°C?
A.
B.
C.
D.
E.
C3H8
Kr
N2
H2S
Ar
17. Which one of the following molecules is polar?
A.
B.
C.
D.
E.
PBr5
SnCl4
CHCl3
XeF2
XeF4
18. A mixture of three gases has a total pressure of 1,380 mmHg at 298 K. The mixture is
analyzed and is found to contain 1.27 mol CO2, 3.04 mol CO, and 1.50 mol Ar. What is the
partial pressure of Ar?
A.
B.
C.
D.
E.
0.258 atm
301 mmHg
356 mmHg
5,345 mmHg
8,020 mmHg
19. Arrange the following ions in order of increasing ionic radius, K+ , P3- , S2- , Cl- .
Increasing radius
A.
B.
C.
D.
E.
K+ , Cl- , S2- , P3K+ , P3- , S2- , ClP3- , S2- , Cl- , K+
Cl- , S2- , P3- , K+
Cl- , S2- , K+ , P3-
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Swamy
Fall 2013
20. The maximum number of electrons in a atom that have the following set of quantum numbers
is
n=4
A.
B.
C.
D.
E.
l=+3
ml = -2
ms = + 1/2
0
1
2
6
10
21. Four identical flasks contain three different gases at standard temperature and pressure. Flask
A contains C2 H2 , Flask B contains CO2 , Flask C contains N2 and Flask D contains Ar.
Which flask contains the most number of atoms?
A.
B.
C.
D.
E.
Flask A
Flask B
Flask C
Flask D
They all contain the same number of atoms.
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Answer Key for Test “CHM 1045 Swamy Practice Exam 2”, 11/20/13
No. in No. on
Q-Bank Test Correct Answer
9 115
10 6
7 44
9 101
9 60
10 17
5 47
5 104
8 36
7 120
7 19
10 28
10 11
9 47
5 25
5 137
10 78
5 38
8 49
7 21
5 111
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
B
D
C
B
E
E
E
E
D
B
B
D
A
D
B
B
C
C
A
B
A
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