SAMPLE FINAL EXAMINATION Dr. Slaughter, Instructor NOTE:

Transcription

SAMPLE FINAL EXAMINATION Dr. Slaughter, Instructor NOTE:
SAMPLE FINAL EXAMINATION
Dr. Slaughter, Instructor
NOTE:
This Sample Exam is from a previous General Chemistry
for Engineers class taught by Dr. Slaughter at a different
institution. Some topics on this Exam may not be
covered in 1410, and some topic covered in 1410 may
not be on this Final Exam.
This Sample Exam is intended to give you a general idea
of the type and difficulty of questions I tend to use for
different chemistry topics. It is NOT intended to be a
study guide or a substitute for studying the lecture
notes or problem sets.
FINAL EXAMINATION
Record your answers on the UNMARKED SCANTRON SHEET
F-1.
Using the rules of significant figures, calculate the following:
8.925 8.905
8.925
A)
B)
C)
D)
E)
F-2.
Steam reforming of methane to produce hydrogen
Polymerization of ethene to polyethylene
Crystallization of rock salt from seawater
Production of biodiesel from soybean oil
Incineration of trash to produce energy
The systematic name for Al2O3 is:
A)
B)
C)
D)
E)
F-4.
2.240 x 10−3
0.2241
0.224
0.22
2. x 10−1
Which of the following involves only physical changes?
A)
B)
C)
D)
E)
F-3.
100.
aluminum oxide
aluminum trioxide
dialuminum trioxide
aluminum(III) oxide
aluminum(II) trioxide
What mass of calcium chloride, CaCl2, is needed to prepare 2.850 L of a 1.56 M solution?
A)
B)
C)
D)
E)
25.9 g
111 g
203 g
336 g
493 g
1
(Questions F-5 to F-6):
The reusable booster rockets on the U.S. Space Shuttle use a solid
fuel composed of aluminum powder and ammonium perchlorate,
which react according to the following equation:
3Al (s) + 3NH4ClO4 (s)  Al2O3 (s) + AlCl3 (s) + 3NO (g) + 6H2O (g)
F-5.
How many moles are there in 1000. kg of ammonium perchlorate?
A)
B)
C)
D)
E)
F-6.
8.511 x 103 mol
1.439 x 104 mol
1.175 x 105 mol
6.949 x 107 mol
1.175 x 108 mol
How many grams of water are released in the rocket exhaust when 1000. kg of
ammonium perchlorate react completely with excess aluminum powder ?
A)
B)
C)
D)
E)
944.6 g
1.702 x 103 g
7.668 x 104 g
3.067 x 105 g
9.202 x 105 g
(Questions F-7 to F-9):
Balance the following oxidation-reduction reaction, assuming it
occurs in acidic aqueous solution:
Cl− (aq) + MnO4− (aq)  Cl2 (g) + Mn2+ (aq)
F-7.
The oxidation state of manganese in MnO4− is:
A)
B)
C)
D)
E)
F-8.
−1
+3
+5
+7
+8
In the balanced equation, the coefficient of H2O is:
A)
B)
C)
D)
E)
2
4
8
16
There is no H2O in the balanced equation
2
F-9.
In the balanced equation, the coefficient of Cl− is:
A)
B)
C)
D)
E)
2
5
7
10
14
F-10. A helium balloon has a volume of 12.4 L with the gas at 23.0 °C and 0.956 atm. When
the gas temperature rises to 40.0 °C and its pressure changes to 1.20 atm, what is the new
volume of the balloon?
A)
B)
C)
D)
E)
0.488 L
6.28 L
12.4 L
10.4 L
17.2 L
F-11. Which of the following gases would have a higher rate of effusion than C2H2 (acetylene)?
A)
B)
C)
D)
E)
N2
O2
Cl2
CH4
CO2
F-12. In a particular atom, what is the maximum number of electrons that can have the quantum
numbers n = 4, ℓ = 3, ms = +½?
A)
B)
C)
D)
E)
1
2
5
7
10
F-13. What is the correct electron configuration for the Mn3+ ion?
A)
B)
C)
D)
E)
[Ar]3d4
[Ar]4s24d5
[Ar]4s23d5
[Ar] 4s23d3
[Ar] 4s23d2
3
F-14. List the elements Al, Si, and C in order of increasing atomic radius.
A)
B)
C)
D)
E)
Al, Si, C
Al, C, Si
C, Al, Si
C, Si, Al
Si, Al, C
(Questions F-15 to F-16):
Draw a correct Lewis structure for ClF3.
F-15. What is the electron pair geometry around the central atom?
A)
B)
C)
D)
E)
Trigonal planar
Tetrahedral
Square planar
Trigonal bipyramidal
See-saw
F-16. According to VSEPR, what is the molecular geometry of ClF3?
A)
B)
C)
D)
E)
Trigonal planar
Tetrahedral
Trigonal pyramidal
See-saw
T-shaped
(Questions F-17 to F-19):
Draw a correct Lewis structure for sulfur dioxide, SO2 (remember
that “correct” means with formal charges minimized).
F-17. What is the hybridization of the sulfur atom?
A)
B)
C)
D)
E)
sp
sp2
sp3
sp3d
sp3d2
F-18. Which of the following statements is correct regarding formal charges in SO2?
A)
B)
C)
D)
E)
No atom in SO2 has a formal charge
Sulfur has no formal charge but both oxygens have −1 formal charges
Sulfur has a +1 formal charge and one oxygen has a −1 formal charge
Sulfur has a +2 formal charge and both oxygens have −1 formal charges
Sulfur has a −2 formal charge and both oxygens have +1 formal charges
4
F-19. How many  and  bonds are present in SO2?
A)
B)
C)
D)
E)
2  bonds, 1  bond
no  bonds, 2  bonds
1  bond, 1  bond
2  bonds, no  bonds
2  bonds, 2  bonds
F-20. Given the following standard enthalpies of formation:
ΔH°f
SiCl4(ℓ)
SiO2(s)
HCl(aq)
H2O(ℓ)
−687 kJ/mol
−911 kJ/mol
−167 kJ/mol
−286 kJ/mol
Calculate ΔH°rxn for the following balanced reaction (as written). This reaction is used in
the production of industrial high-grade quartz (SiO2):
SiCl4(ℓ) + 2H2O(ℓ)
A)
B)
C)
D)
E)

SiO2(s)
−105 kJ
−320. kJ
+105 kJ
−606 kJ
−2.84 x 103 kJ
5
+
4HCl(aq)
HELP SHEET
Periodic Table of the Elements
1
18
1
2
H
1.008
2
13
14
15
16
17
He
4.003
3
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
6.941 9.012
11
10.81 12.01 14.01 16.00 19.00 20.18
12
Na Mg
22.99 24.31
3
4
5
6
7
8
9
10
11
12
25
13
14
15
16
17
18
Al
Si
P
S
Cl
Ar
26.98 28.09 30.97 32.07 35.45 39.95
19
20
21
22
23
24
26
27
28
29
30
31
32
33
34
35
36
K
Ca
Sc
Ti
V
Cr Mn Fe
Co
Ni
Cu
Zn
Ga Ge
As
Se
Br
Kr
39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.93 58.69 63.55 65.38 69.72 72.59 74.92 78.96 79.90 83.80
37
38
39
40
41
Rb
Sr
Y
Zr
Nb Mo Tc
42
43
45
46
47
48
49
50
51
52
53
54
Ru Rh
44
Pd
Ag Cd
In
Sn
Sb
Te
I
Xe
85.47 87.62 88.91 91.22 92.91 95.94 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3
55
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au Hg
Tl
Pb
Bi
Po
At
Rn
132.9 137.3 138.9 178.5 108.9 183.9 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 (209) (210) (222)
87
88
89
Fr
Ra
Ac
(223) (226) (227)
Electronegativities of the Elements (For Compounds, In Pauling Units)
1
H
2.1
2
Li
Be
B
C
N
O
F
1.0
1.5
2.0
2.5
3.0
3.5
4.0
13
Na Mg
0.9
1.2
3
K
Ca
Sc
0.8
1.0
1.3
4
14
15
16
17
18
He
-Ne
--
Al
Si
P
S
Cl
9
10
11
12
1.5
1.8
2.1
2.5
3.0
Cr Mn Fe
Co
Ni
Cu
Zn
Ga Ge
As
Se
Br
1.6
1.9
1.9
1.9
1.6
1.6
1.8
2.0
2.4
2.8
Kr
--
5
6
Ti
V
1.5
1.6
7
1.5
8
1.8
Ar
--
Rb
Sr
Y
Zr
Nb Mo Tc
Ru Rh
Pd
Ag Cd
In
Sn
Sb
Te
I
Xe
0.8
1.0
1.2
1.4
1.6
1.8
1.9
2.2
2.2
1.9
1.7
1.8
1.9
2.1
2.5
--
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au Hg
Tl
Pb
Bi
Po
At
0.7
0.9
1.1
1.3
1.5
1.7
1.9
2.2
2.2
2.2
2.4
1.8
1.9
1.9
2.0
2.2
Rn
--
Fr
Ra
Ac
0.7
0.9
1.1
2.2
6
1.7
1.9
Electron Pair Geometries
# e- Pairs*
e- Pair
Geometry
Ideal Angle
Between e- Pairs
Hybridization
2
Linear
180°
sp
3
Trigonal
planar
120°
sp2
4
Tetrahedral
109.5°
sp3
5
Trigonal
bipyramidal
axial-equatorial:
90°
sp3d
equatorialequatorial:
120°
6
Octahedral
sp3d2
90°
7
Conversion Factors
Prefixes for Compound Names
(Inorganic Compounds)
Prefix
# of Atoms
mono1
di2
tri3
tetra4
penta5
hexa6
hepta7
octa8
nona9
deca10
1 atm = 760 Torr
1 J = 1 kg·m2/s2
1 cm = 10-2 m
1 nm = 10-9 m
1 kJ = 1000 J
1 Hz = 1 s-1
T(K) = T(°C) + 273.15
Constants
R = 0.08206 L·atm/mol·K (pressure units)
= 8.31451 J/mol·K
(energy units)
Prefixes for Organic Compound
Names
Prefix
# of Carbons
meth1
eth2
prop3
but4
pent5
hex6
hept7
oct8
non9
dec10
Avogadro’s Number 6.022 x 1023 mol-1
Molar gas volume
22.4 L
Gas Laws
Boyle’s Law P1V1 = P2V2
Charles’s Law
V1 V2

T1 T2
Ideal Gas Law PV = nRT
Graham’s Law of Effusion
r1
M2

r2
M1
8