Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
Constants/Conversions
C=3.00 x 108 m/s
e =1.602 x 10-19 Coul
1 amu= 1.66054 x 10-24 g
NA = 6.02214 x 1023
h = 6.626 x 10-34 JS
R = 8.3145 J/K°mol
= 0.082058 L atm/ K°mol
k = 1.38066 x 1023 J/K°
1 L atm = 101.325 J
1 J = 107 erg
RH = 2.18 x 10-18 J
1atm = 760 torr = 760 mm-Hg = 1.01325 x105 Pa
1 Cal = 4.184 J
1 eV = 96.45 kJ/mol
Equations
E = hv C= vλ
K = °C + 273.15
ΔT = kfm
1
En = (-RH) 2
n
π = MRT
ΔE = q + w
E = hc/λ
EΨ = HΨ
ΔT= kbm
λ = h/mv
Ecell = Ered + Eox
q = CΔT = n CΔT = m s ΔT
ΔH Vap ⎛ 1
P
1
ln ( 1 ) = ⋅ ⎜⎜ −
P2
R
⎝ T1 T2
q
m ⋅ ΔT
Specific Heat =
E ∝ (Q+ Q)/d
R1/R2 = (M1/M2)-1/2
t1/2 = 0.693/k
Ln A = ln A0 -kt
Δn
KP = KC (RT)
KaKb = Kw = 1 x 10-14
F = 96,485 Coul/mol
Cu2+ + 2e- → Cu(S)
[base]
pH = pKa + log(
) ΔG = ΔG° =RT⋅ ln (Q)
[acid]
ΔS°rxn = ΣnΔSf°(products) - ΣmΔSf°(reactants)
ΔH°rxn = ΣnΔH°f(product)-ΣnΔH°(reactant)
nλ = 2d⋅sinθ ΔG = ΔH -TΔS
k = A⋅exp(-Ea/RT)
1/A = 1/A0 -kt
E° = + 0.337
2.303 ⋅ RT
E = E° ⋅log (Q)
nF
ΔG = -nFE
P1 = χ1PTotal
1A
8A
1
1
2
H
He
1.008 2A
3
4
2
Li
3A
5
Na
B
K
Mg
Ca
5A
7
C
6A
8
N
7A
4.003
10
F
Ne
9
O
10.81 12.01 14.01 16.00 19.00 20.18
13
14
15
16
17
18
Al
22.99 24.31
3B
19
20
21
4
4A
6
Be
6.941 9.012
11
12
3
⎞
⎟⎟
⎠
Sc
4B
22
5B
23
6B
24
Ti
V
Cr
7B
25
Mn
26
Fe
8B
27
Co
28
Ni
1B
29
2B
30
Cu
Zn
Si
P
S
Cl
Ar
26.98 28.09 30.97 32.07 35.45 39.95
31
32
33
34
35
36
Ga
Ge
As
Se
Br
Kr
39.10 40.08 44.96 47.90 50.94 52.00 54.94 55.85 58.93 58.70 63.55 65.39 69.72 72.59 74.92 78.96 79.90 83.80
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
5
Rb
Sr
Y
Zr
Nb
Mo
Tc
85.47 87.62 88.91 91.22 92.91 95.94 (98)
55
56
57
72
73
74
75
6
Cs
Ba
La
Hf
Ta
W
Re
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 192.2 195.1 197.0 200.6 204.4 207.2 209.0 (209) (210)
87
88
89
104
105
106
107
108
109
110
111
7
Fr
Ra
(223) (226)
Ac
Rf
Ha
Sg
Ns
(227) (261) (262) (266) (262)
58
6
Ce
59
Pr
60
Nd
61
Pm
Xe
101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3
76
77
78
79
80
81
82
83
84
85
86
Hs
Rn
(222)
Mt
(265) (266)
62
Sm
63
Eu
64
Gd
65
Tb
66
Dy
67
Ho
68
Er
69
Tm
70
Yb
71
Lu
140.1 140.9 144.2 (145) 150.4 152.0 157.3 158.9 162.5 164.9 167.3 168.9 173.0 175.0
90
91
92
93
94
95
96
97
98
99
100
101
102
103
7
Th
Pa
U
Np
232.0 (231) 238.0 (244)
Pu
Am
Cm
Bk
Cf
(242) (243) (247) (247) (251)
Es
Fm
Md
No
Lw
(252) (257) (258) (259) (260)
1
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
2
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
molecule
CH4(g)
HCl(g)
CHCl3(l)
HF(g)
CH3OH(l)
CO(g)
HNO3(l)
CO2(g)
H2O(g)
H2O(l)
ΔHf˚
-74.8
-92.3
-131.8
-268.6
-238.6
-110.5
-173.2
-393.5
-241.8
-285.8
3
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
4
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
MULTIPLE CHOICE QUESTIONS (60)
0. Your Section number is
A. 01 (Monday Lab)
B. 02 (Wednesday Lab)
1. Potassium chloride, KCl, is the product of the reaction of elemental potassium (K) and
elemental chlorine (Cl2). Potassium chloride is best described as
A. an element.
B. a homogeneous mixture.
C. a heterogeneous mixture.
D. a chemical compound.
2. Which of the following are physical properties of aluminum?
1) Aluminum conducts electricity.
2) In the presence of oxygen, a thin layer of aluminum oxide forms on its surface.
3) Hydrochloric acid reacts with aluminum, releasing hydrogen gas as one product.
A.
B.
C.
D.
1 only.
2 only.
3 only.
1 and 2.
3. The radius of a lithium atom is 152 pm. What is this radius in cm?
A. 1.52 × 10-12 cm
B. 1.52 × 10-10 cm
C. 1.52 × 10-8 cm
D. 1.52 × 10-9 cm
4. cube of lead with 25.4 mm dimensions on each side is submerged in a beaker of water. What
volume of water (in liters) is displaced?
A. 0.0164 L
B. 0.0254 L
C. 0.254 L
D. 1.64 L
2-
5. How many protons, neutrons and electrons are in an O atom?
A. 8 protons, 8 neutrons, 10 electrons
B. 8 protons, 10 neutrons, 10 electrons
C. 8 protons, 10 neutrons, 8 electrons
D. 10 protons, 8 neutrons, 10 electrons
6. Vodka is a mixture of ethanol (C2H5OH) and water (H2O). Vodka is best described as
A. an element.
B. a heterogeneous mixture.
C. a homogenous mixture.
D. a chemical compound.
7. What alkaline earth metal is located in the second period?
5
Foothill College
Chem25 Exam1A
A.
B.
C.
D.
Oct. 14, 2009
Name:
Be
Mg
Li
B
8. When methane is burned with oxygen, the products are carbon dioxide and water. If you
produce 9 grams of water and 11 grams of carbon dioxide from 16 grams of oxygen, how many
grams of methane were needed for the reaction?
A. 20
B. 40
C. 4
D. 31
9. Which grouping of elements is composed entirely of nonmetals?
A. hydrogen, bismuth, and radon
B. helium, nitrogen, and chlorine
C. cadmium, bromine, and neon
D. silicon, fluorine, and argon
10. Which of the following statements about atoms is FALSE?
A. Atoms are responsible for the sensation of smell.
B. Atoms are the basic building block of nature.
C. An atom is the smallest identifiable unit of an element.
D. All of the above statements are true.
11. Which statement below accurately describes the contributions of Thomson?
A. ancient Greek philosopher who proposed that matter was continuous
B. created the modern periodic table
C. proposed the modern Atomic Theory
D. discovered the existence of electrons
12. Cr is a member of which family?
A. noble gases
B. halogens
C. alkaline earth metals
D. transition metals
13. Which of the following statements about matter is FALSE?
A. Matter occupies space and has mass.
B. Matter is smooth and continuous.
C. Matter exists in either a solid, liquid or gas state.
D. Matter is ultimately composed of atoms.
14. Which of the following statements about matter is FALSE?
A. Matter occupies space and has mass.
B. Matter exists in either a solid, liquid or gas state.
C. Matter is ultimately composed of atoms.
6
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
D. Matter is smooth and continuous.
15. Which of the following statements about the nature of electrical charge is FALSE?
A. Positive and negative electrical charges attract each other.
B. Positive-positive or negative-negative charges repel each other.
C. Positive and negative charges cancel each other so that a proton and electron, when
paired, are charge neutral.
D. All of the above statements are true.
16. A 15.0 gram lead ball at 25.0 °C was heated with 40.5 joules of heat. Given the specific heat of
lead is 0.128 J / g °C , what is the final temperature of the lead?
A. 21.1 °C
B. 77.8 °C
C. 46.1 °C
D. 0.844 °C
17. All of the following statements about different elements are true EXCEPT:
A. Ba is an alkaline earth metal.
B. Mn is a transition metal.
C. S is considered a metalloid.
D. Kr is one of the noble gases.
18. Ions are formed when atoms
A. gain or lose protons
B. gain or lose electrons
C. gain or lose neutrons
D. Each of these results in ion formation
19. Which of the following statements are correct?
1) An atomic mass unit equals 1/12 the mass of a carbon-12 atom.
2) Mass number equals the number of protons plus neutrons.
3) Elements with identical mass number are isotopes.
A.
B.
C.
D.
1 only.
1 and 3.
3 only.
1 and 2.
20. What is the best answer to report for
A.
B.
C.
D.
3.478 x 1.164
2.00
+ 0.354?
2.3782
2.378
2.38
2.4
7
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
LONG ANSWER （10 pts each）
1. There are only two naturally occurring isotopes of copper, 63Cu (AM= 52.9855) and 65Cu (AM=
64.9277). The average atomic mass of Cu is 63.5463 a.m.u. The natural abundance of the 65Cu
must be about
64.9277X + 52.9855(1-X) = 63.5463
X = 88.4%
2. Butanol is a permitted artificial flavorant used in butter, cream, fruit, rum, whiskey, and ice
cream. Its boiling point is 243.15 °F. Please convert its boiling point to °C.
117.2 °C, 390 K
8
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
SHORT ANSWER (20 pts)
1. Definition. (5 pts)
A. Heat capacity
B. Isotopes
C. Chemical property:
D. Mass number
E. Conservation of mass
2. The density of lead is 11.35 g/cm3. What is the mass of a 10.0 cm diameter lead sphere in kg?
D= 5.94 kg
3. Five successive determinations of the density of an alloy gave the following results:
Mass (g)
31.25
Volume (mL)
3.06
Density (g/mL)
42.68
4.29
27.89
2.73
33.65
3.31
24.31
2.45
The best value to report for the density of the alloy is
Density:
Average:
10.2
10.1
9.95
10.2
10.2
9.92
9
Foothill College
Chem25 Exam1A
Oct. 14, 2009
Name:
4. Please briefly describe the observation of Rutherford’s experiment and his conclusion
5. Please briefly describe the characteristics of three phases of matter and explain the differences
10