1. The density of liquid cesium at 30°C is 1.87 g/mL. Because of its wide liquid range (28 to 678°C), cesium could be used as a barometer fluid at high temperatures. What height of cesium will be supported on a day when the temperature is 30 °C and a mercury barometer reads 740 torr? (The density of mercury is 13.6 g/mL.) (a) 7.27 m (b) 0.040 m (c) 5.38 m (d) 5380 m (e) 0.740 m 2. A cylinder with a moveable piston contains 26.4 cm3 of a gas at 21 °C. If the maximum capacity of the cylinder is 56.8 cm3, what is the temperature to which the cylinder must be heated to extend the piston to its maximum position? (a) 360 °C (b) 462 °C (c) 633 °C (d) 532 °C (e) 280 °C 3. A weather balloon is filled with helium to a volume of 31.5 L at 20 °C and 1.3 atm. In the stratosphere the temperature and pressure are −23 °C and 3.00 × 10−3 atm respectively. What will be the volume of the balloon in the stratosphere? (a) 1.48 × 103 L (b) 2.54 × 103 L (c) 1.00 × 104 L (d) 1.16 × 104 L (e) 1.48 × 104 L 4. A 4.40 g piece of solid CO2 (dry ice) is allowed to sublime in a balloon. The final volume of the balloon is 1.00 L at 300 K. What is the pressure of the gas? (a) 246 atm (b) 2.46 atm (c) 0.122 atm (d) 122 atm (e) 24.6 atm 5. Four identical 1.0-­‐L flasks contain the following gases each at 0°C and 1 atm pressure. Which gas has the lowest density? (a) HCl (b) Cl2 (c) CH4 (d) SO2 (e) C2H4 6. Which of the following samples contains molecules with the greatest average kinetic energy? (a) 1.0 mol N2 at 580 K (b) 0.3 mol CO2 at 440 K (c) 2.0 mol CO at 298 K (d) 0.5 mol O2 at 480 K (e) 2.5 mol N2O at 140 K 7. A mixture of neon and argon is 25.0% neon by mass. What is the partial pressure of neon in the mixture at standard temperature and pressure (0 °C and 1 atm)? The atomic masses of Ne and Ar are 20.18 and 39.95 g/mol, respectively. (a) 460 torr (b) 301 torr (c) 520 torr (d) 250 torr (e) 380 torr 8. Which gases, N2O, C2H2, NO, diffuse more slowly than O2 under identical experimental conditions? (a) N2O only (b) C2H2 only (c) NO only (d) NO and C2H2 (e) N2O and C2H2 9. Which of the following gases will exhibit the least ideal behavior? (a) N2 (b)N2H4 (c) CH4 (d) Ne (e) F2 10. Which of the following effects will make PV/RT less than 1 for a 1.0 mole sample of a real gas? (a) The gas molecules are large enough to occupy a substantial amount of space (b) A large number of molecules have speeds greater than the average speed. (c) The gas molecules have very low molecular weights. (d) The gas molecules attract one another (e) The gas molecules are placed in a larger container 11. Which of the following substances has the lowest normal boiling point? (a) H2O (b) H2S (c) H2Se (d) H2Te 12. For each of the following pairs determine the substance with the higher normal boiling
point: (1) Cl2 or Br2, (2) acetic acid CH3COOH or 1-propanol CH3CH2CH2OH, (3) SO2 or
CO2.
(a)
(b)
(c)
(d)
(e)
Higher
Higher
Higher
Higher
Higher
normal
normal
normal
normal
normal
boiling
boiling
boiling
boiling
boiling
point
point
point
point
point
=
=
=
=
=
Cl2, CH3COOH and SO2
Br2, CH3CH2CH2OH and SO2
Cl2, CH3COOH and SO2
Br2, CH3COOH and SO2
Br2, CH3COOH and CO2
13. Three organic molecules are shown below: acetone, 2-methyl propane and
isopropanol.
acetone
2-methyl propane
isopropanol
CH3COCH3
CH3CHCH3CH3
CH3CHOHCH3
molar mass = 58 g/mol
molar mass = 57 g/mol
molar mass = 60 g/mol
Which of the following answers correctly arranges these three substances in order of increasing normal boiling point? (a)
(b)
(c)
(d)
(e)
Lowest b.p. CH3COCH3 < CH3CHCH3CH3 < CH3CHOHCH3 highest b.p. Lowest b.p. CH3CHCH3CH3 < CH3COCH3 < CH3CHOHCH3 highest b.p. Lowest b.p. CH3CHOHCH3 < CH3COCH3 < CH3CHCH3CH3 highest b.p. Lowest b.p. CH3CHCH3CH3 < CH3CHOHCH3 < CH3COCH3 highest b.p. Lowest b.p. CH3CHOHCH3 < CH3CHCH3CH3 < CH3COCH3 highest b.p. 14. Given below are the temperatures at which two different liquid compounds with the same empirical formula have a vapor pressure of 400 torr. Compound Temperature (°C) Dimethyl ether, H3COCH3 −37.8 Ethanol, CH3CH2OH 63.5 Which of the following statements is FALSE? (a) Increasing the temperature will increase the vapor pressure of both liquids. (b) Intermolecular attractive forces are stronger in (liquid) ethanol than in (liquid) dimethyl ether. (c) The normal boiling point of dimethyl ether will be higher than the normal boiling point of ethanol. (d) The reason that ethanol reaches a vapor pressure of 400 torr at a higher temperature than dimethylether is that there is strong hydrogen bonding in ethanol, but not in dimethyl ether. 15. Which of the following phase transitions is exothermic? (a) Vaporization (b) Melting (c) Sublimation (d) Freezing (e) None of the above processes are exothermic 16. Which of the following statements regarding viscosity is FALSE? (a) Viscosity increases as the strength of the intermolecular forces increases (b) Viscosity increases as the temperature decreases (c) Viscosity is generally higher for a liquid with large nonpolar molecules than it is for a liquid with small nonpolar molecules (d) All other things being equal viscosity is higher for a liquid with rigid molecules than it is for a liquid with flexible molecules (e) As the number of hydrogen bonds a molecule can form increases the viscosity increases 17. If 40.0 kJ is added to 36.0 g of solid H2O (ice) initially at a temperature of −25.0 °C what is the final temperature of the H2O? The specific heat of solid H2O is 2.03 J/g·∙K, liquid H2O is 4.18 J/g·∙K, and gaseous H2O is 1.84 J/g·∙K. The heat of fusion is 6.01 kJ/mol and the heat of vaporization is 40.67 kJ mol. The melting and boiling points of water are 0 and 100 °C respectively. (a) 273 K (b) 312 K (c) 405 K (d) 373 K (e) 380 K 18. Which of the following descriptions best describes the characteristics of molecules that are prone to form liquid crystalline phases? (a) Nonpolar, rigid molecules with a rodlike shape (b) Polar, rigid molecules with a rodlike shape (c) Nonpolar, flexible molecules with a spherical shape (d) Polar, rigid molecules with a spherical shape (e) Polar, flexible molecules with a rodlike shape 19. The table below gives the temperature and pressure of the triple point for five different substances. Substance Temperature (K) Pressure (atm) Xe 161 0.80 UF6 337 1.50 I2 387 0.12 CO 68 0.15 Zn 693 6.4 × 10−4 On heating from low temperature at 1 atm of pressure which substance is most likely to sublime rather than melt? (a) Xe (b) UF6 (c) I2 (d) CO (e) Zn 20. Consider the properties of ruthenium (IV) oxide and ruthenium (VIII) oxide given in the table below Compound Appearance Melting point Electrical Properties Solubility in H2O RuO2 Black crystalline solid 1300 °C Conducting Insoluble RuO4 Yellow crystalline solid 25 °C Insulating Slightly soluble How would you classify these two solids? a.
b.
c.
d.
e.
Both RuO2 and RuO4 are ionic solids Both RuO2 and RuO4 are metallic solids Both RuO2 and RuO4 are molecular solids RuO2 is a covalent-­‐network solid and RuO4 is a molecular solid RuO2 is a ionic solid and GeBr4 is an molecular solid 21. For the 2D crystal structure shown below what is the lattice type and how many atoms are there per unit cell? (a)
(b)
(c)
(d)
(e)
Lattice = rectangular, Atoms per unit cell = 1 A + 2 B Lattice = rectangular, Atoms per unit cell = 1 A + 3 B Lattice = square, Atoms per unit cell = 1 A + 3 B Lattice = square, Atoms per unit cell = 1 A + 1 B Lattice = square, Atoms per unit cell = 1 A + 2 B 22. For the 2D crystal structure shown below what is the lattice type and how many atoms are there per unit cell? (a)
(b)
(c)
(d)
(e)
Lattice = hexagonal, Atoms per unit cell = 1 A + 1 B Lattice = oblique, Atoms per unit cell = 1 A + 2 B Lattice = centered rectangular, Atoms per unit cell = 2 A + 4 B Lattice = rectangular, Atoms per unit cell = 1 A + 1 B Lattice = hexagonal, Atoms per unit cell = 1 A + 2 B 23. Which of the following properties of metals cannot be adequately explained by the electron sea model? (a) The high electrical conductivity of metals (b) The high thermal conductivity of metals (c) The close packed structures of most metals (d) The high melting points of metals in the middle of the transition series, like rhenium (Re) and tungsten (W) (e) The low melting points of metals at the very end of the transition series, like cadmium (Cd) and mercury (Hg) 24. Tantalum crystallizes with a body centered cubic structure. Given the molar mass (180.95 g/mol) and the density of tantalum, ρ = 16.69 g/cm3 at 20 °C, what value would you calculate for the radius of a tantalum atom? (a) 1.16 Å (0.116 nm) (b) 1.25 Å (0.125 nm) (c) 1.35 Å (0.135 nm) (d) 1.42 Å (0.142 nm) (e) 1.54 Å (0.154 nm) 25. Which of the following metals will have the highest melting point: Rb, Re, Sr, Cd or Au? a. Rb b. Re c. Sr d. Cd e. Au 26. One unit cell of the crystal structure of a cubic compound that forms between copper and oxygen is shown below (the black spheres are copper and the gray spheres are oxygen). If the density of this compound is 4.95 g/cm3, and the ionic radius of the oxide ion is 1.26 Å, what is the radius of the copper ion? Assume the atoms touch along the bonds shown in the figure. a. 0.46 Å b. 0.60 Å c. 0.74 Å d. 0.96 Å e. 1.28 Å 27. If you were to take the zinc blende crystal structure and make all of the atoms the same, what structure type would result? (a) Hexagonal close packed metal (e.g. Zn) (b) Face centered cubic metal (e.g. Al) (c) Body centered cubic metal (e.g. Na) (d) Primitive cubic metal (e.g. Po) (e) Diamond structure (e.g. Si) 28. Which of the following statements is false? a. In a semiconductor the molecular orbitals in the valence band are filled and those in the conduction band are empty b. In a semiconductor the molecular orbitals in the conduction band are bonding molecular orbitals and those in the valence band are antibonding molecular orbitals c. Replacing a tiny fraction of silicon atoms with aluminum atoms would produce a p-­‐
type semiconductor d. As the bond distance in a semiconductor increases the band gap decreases e. Many compound semiconductors have the zinc blende structure 29. Arrange the following compound semiconductors from lowest to highest band gap: GaP, GaN, InSb, InAs (a) Smallest band gap InAs < InSb < GaN < GaP Largest band gap (b) Smallest band gap GaN < GaP < InAs < InSb Largest band gap (c) Smallest band gap InSb < InAs < GaP < GaN Largest band gap (d) Smallest band gap InSb < InAs < GaN < GaP Largest band gap (e) Smallest band gap GaN < GaP < InAs < InSb Largest band gap 30. The first light emitting diodes (LEDs) were made from GaAs which has a band gap of 1.43 eV. What wavelength of light would be emitted from an LED built from GaAs? (a)
(b)
(c)
(d)
(e)
565 nm (green light) 868 nm (infrared light) 477 nm (blue light) 680 nm (red light) None of the above Equations Pressure P = F a Ideal gas law PV = nRT Dalton’s Law of Partial Pressures ⎛ RT ⎞
⎛ RT ⎞
⎛ RT ⎞
PTot = P1 + P2 + P3 + ... = n1 ⎜
⎟ + n2 ⎜
⎟ + n3 ⎜
⎟ + ... ⎝ V ⎠
⎝ V ⎠
⎝ V ⎠
Ekinetic
mu 2
=
2
Root mean square speed of a gas urms =
3RT
M
van der Waals Equation ⎛
n 2 a ⎞
⎜⎜ P + 2 ⎟⎟(V − nb ) = nRT V ⎠
⎝
Kinetic energy Physical Constants and Conversion Factors Avogadro’s Number → N = 6.022 × 1023 Planck’s Constant → h = 6.626 × 10-­‐34 J-­‐s Speed of Light → c = 3.00 × 108 m/s Charge of an Electron → e = 1.602 × 10-­‐19 C Ideal Gas Constant → R = 0.08206 L-­‐atm/mol-­‐K = 8.314 J/mol-­‐K = 63.26 L-­‐torr/mol-­‐K Atmospheric Pressure → 1 atm = 760 torr = 760 mm Hg = 101,325 Pa = 0.9869 bar Temperature Conversions → K = 273 + °C STP → 273 K and 1 atm 1 mL = 1 cm3 1 Å = 1 × 10−8 cm = 1 × 10−10 m 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
IA
18
VIIIA
1
2
H
He
1.008
IIA
IIIA
IVA
VA
VIA
VIIA
3
4
5
6
7
8
9
4.003
10
Li
Be
B
C
N
O
F
Ne
6.941
11
9.012
12
10.811
12.011
14.007
15.999
18.998
20.179
13
14
15
16
17
18
Na
Mg
Al
Si
P
S
Cl
Ar
22.990
19
24.305
20
26.982
31
28.086
32
30.974
33
32.066
34
35.453
35
39.948
36
IIIB
VIB
VB
VIB
VIIB
21
22
23
24
25
26
27
28
IB
IIB
29
30
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
39.098
37
40.078
38
44.956
39
47.88
40
50.942
41
51.996
42
54.938
43
55.847
44
58.933
45
58.69
46
63.546
47
65.39
48
69.723
49
72.61
50
74.922
51
78.96
52
79.904
53
83.80
54
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
85.468
55
87.62
56
88.906
57
91.224
72
92.906
73
95.94
74
(98)
75
101.07
76
102.90
77
106.42
78
107.87
79
112.41
80
114.82
81
118.71
82
121.75
83
127.60
84
126.90
85
131.29
86
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
178.49
180.95
183.85
186.21
190.2
192.22
195.08
196.97
200.59
204.38
207.2
208.98
(209)
(210)
(222)
Cs
Ba
La*
132.90
137.33
138.90
89
87
88
105
106
107
108
109
Ra
Ac†
104
Fr
Unq
Unp
Unh
Uns
Uno
Une
(223)
(226)
(227)
(261)
(262)
(263)
(262)
58
59
60
*
Lanthanide
Ce
Pr
Nd
Series
140.12 140.91 144.24
†
Actinide
Series
61
62
63
64
65
66
67
68
69
70
71
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
(145)
150.36
151.96
157.25
158.92
162.50
164.93
167.26
168.93
173.04
174.97
103
90
91
92
93
94
95
96
97
98
99
100
101
102
Th
Pa
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
232.04
231.04
238.03
(237)
(244)
(243)
(247)
(247)
(251)
(252)
(257)
(258)
(259)
(260)