1. (7 points) Two barometers are to be constructed using the liquids mercury and
bromoform (CHBr3), which have densities of 13.6 and 2.89 g/mL, respectively.
What height of columns must be used so that each barometer may measure an
atmospheric pressure as high as 825 torr?
a.
b.
c.
d.
e.
825 mm Hg, 3880 mm CHBr3
3880 mm Hg, 825 mm CHBr3
825 mm Hg, 175 mm CHBr3
1.09 mm Hg, 14.69 mm CHBr3
3880 mm Hg, 175 mm CHBr3
a.
b.
c.
d.
e.
1 x 103 breaths
2 x 103 breaths
3 x 103 breaths
4 x 103 breaths
5 x 103 breaths
a.
b.
c.
d.
e.
0.404 L
9.91 L
2.61 L
1.52 L
3.67 L
a.
b.
c.
d.
e.
963 torr
440 torr
240 torr
363 torr
545 torr
2. (6 points) An adult human breathes 0.5 L of air at 1.0 atm with each breath. If a
50 L gas cylinder containing air at 1.93 x 103 kPa is available, how many breaths
may be taken from the cylinder?
3. (5 points) A 2.00 L sample of air at 23°C is warmed to 114°C. What is the new
volume (in L) if the pressure remains constant?
4. (6 points) A 2.00 L sample of air at –55°C has a pressure of 725 torr. What will
the new pressure (in torr) be if the temperature is raised to 55°C and the volume
is increased to 4.00 L with the amount of gas held constant?
1
5. (6 points) The Goodyear blimp contains 5.1 x 106 liters of helium at 24°C and
770 torr. How much helium does the blimp contain (in kg)?
a.
b.
c.
d.
e.
6.4 x 108 kg
6.4 x 105 kg
8.5 x 105 kg
8.5 x 102 kg
1.9 x 102 kg
a.
b.
c.
d.
e.
120 g/L
10 g/L
1.3 g/L
1.1 g/L
0.12 g/L
6. (6 points) Air is comprised primarily of N2, O2, and Ar with mole fractions of
0.78, 0.21, and 0.009 respectively. What is the density of air (in g/L) at STP?
7. (7 points) Oxygen gas is generated by the reaction the decomposition reaction:
2 KClO3 (s) 2 KCl (s) + 3 O2 (g)
The oxygen gas is collected over water at 27°C in a 2.00-L vessel a total pressure
of 753 torr. Given that the vapor pressure of H2O at 27°C is 26.0 torr, how many
grams of KClO3 were consumed in the reaction?
a.
b.
c.
d.
e.
0.0777 g
6.41 g
9.52 g
11.6 g
0.0513 g
a.
b.
c.
d.
e.
599 m/s
7.59 x 105 m/s
86.5 m/s
759 m/s
871 m/s
8. (5 points) What is the rms speed (in m/s) of NH3 at 245°C?
2
9. (6 points) Which of the following properties of a real gas is related to the
definition of the "b" coefficient in the van der Waals equation?
a. Real gases consist of molecules or atoms which have a finite volume.
b. The average speed of the molecules of a real gas increases with
temperature.
c. There are attractive forces between atoms or molecules of a real gas.
d. The rate of effusion of a gas which is inversely proportional to the square
root of the molar mass of the gas.
e. None of the above statements are related to the “b” constant.
10. (5 points) Which of the following has the highest normal boiling point?
a.
b.
c.
d.
e.
GeH4
SnH4
CH4
SiH4
H2
11. (5 points) Which of the following molecules can form intermolecular hydrogen
bonds as a pure liquid?
CH3CH2OH
(I)
a.
b.
c.
d.
e.
CH3CH2F
(II)
CH3CH2NH2
(III)
I, II, and III
II and IV
I and III
All molecules form hydrogen bond interactions
None of the molecules form hydrogen bond interactions
CH3CH2SH
(IV)
12. (6 points) Which of the following DECREASES as the strength of the
intermolecular forces INCREASES?
a.
b.
c.
d.
e.
The heat of vaporization.
The normal boiling temperature.
The extent of deviations from the ideal gas law.
The sublimation temperature of a solid.
The vapor pressure of a liquid.
3
13. (6 points) Which member of each of the following pairs of liquid substances have
the highest surface tension?
(CH3)3CCH2CH3 vs. CH3CH2CH2CH2CH2CH3
CH2Cl2 vs. CH3Cl
H2O at 25˚C vs. H2O at 75˚C
a.
b.
c.
d.
e.
(CH3)3CCH2CH3, CH2Cl2, H2O at 25˚C
(CH3)3CCH2CH3, CH3Cl, H2O at 75˚C
CH3CH2CH2CH2CH2CH3, CH2Cl2, H2O at 25˚C
CH3CH2CH2CH2CH2CH3, CH2Cl2, H2O at 75˚C
CH3CH2CH2CH2CH2CH3, CH3Cl, H2O at 25˚C
a.
b.
c.
d.
e.
1.5 x 102 kJ
4.9 x 104 kJ
1.1 x 103 kJ
49 kJ
61 kJ
14. (7 points) Ethanol (CH3CH2OH) melts at –114˚C and boils at 78˚C. Its heat of
fusion and vaporization are 5.02 and 38.56 kJ/mol, respectively. The heat
capacities of the solid and liquid are 0.97 and 2.3 J/g-K, respectively. How much
heat is required to change 2.25 moles of solid ethanol at –134˚C to ethanol
vapors at 78˚C?
15. (6 points) Given the phase diagram, which of the following statements is FALSE?
a. The solid has a higher density than the liquid.
b. Sublimation and deposition are the only phase changes possible at
temperatures and pressures below point B.
c. When the liquid phase, phase 2, is compressed at constant temperature, no
phase change is possible.
d. When heated at 1 atm, this substance will first melt, then boil.
e. It is possible that this phase diagram is for water.
4
16. (6 points) How many atoms are in a single unit cell of the types simple
(primitive) cubic, body-centered cubic, and face-centered cubic, respectively?
Simple
12
6
4
1
6
a.
b.
c.
d.
e.
Body-centered
8
8
2
2
3
Face-centered
6
12
1
4
2
17. (7 points) The density of face-centered cubic platinum (Pt) is 21.5 g/cm3 at 20°C.
What is the length of an edge of a single unit cell (in pm)?
a.
b.
c.
d.
e.
392
362
515
426
349
18. (6 points) Select the member of each pair of substances that has the highest
melting point.
a.
b.
c.
d.
e.
I. CH4 vs. CCl4
CH4, MgF2, KF
CCl4, MgF2, CaO
CCl4, MgCl2, KF
CCl4, MgCl2, CaO
none of the above
II. MgF2 vs. MgCl2
III. KF vs. CaO
19. (6 points) Rank the following solute-solvent interactions in order of
INCREASING strength of attraction.
a.
b.
c.
d.
e.
I. KCl in H2O
I < II < III
III < II < I
II < III < I
I < III < II
III < I < II
II. CH3CH2OH in H2O
5
III. CO2 in CCl4
20. (5 points) Which of following substances become LESS soluble in water as
temperature DECREASES?
CaCl2 (s)
(I)
a.
b.
c.
d.
e.
K2Cr2O7 (s)
(II)
I and II
III and IV
II, III, and IV
I, II, III, and IV
None of the substances
,
O2 (g)
(III)
CH4 (g)
(IV)
21. (6 points) Which is the following statements about solutions is FALSE?
a. Two liquids that mix in all proportions are miscible with each other.
b. Solubility of a gas solute in a liquid is directly proportional to pressure.
c. A positive value for ∆Ssoln means the solution is more ordered than the
pure solute and pure solvent.
d. The formation of a solution is possible when ∆Hsoln is negative and ∆Ssoln
is positive.
e. The formation of a solution is not possible when ∆Hsoln is positive and
∆Ssoln is negative.
22. (7 points) A bottle containing 0.500 L water is pressurized with a mixture of
77.5% helium in nitrogen (by mass) to a total pressure of 5.50 atm at 30˚C. The
Henry’s law constants for He in water at 30˚C is 3.7x10 -4 M/atm and the constant
for N2 in water at 30˚C is 6.0x10 -4 M/atm. How many mg of helium and nitrogen
dissolve in water at 30˚C?
a.
b.
c.
d.
e.
3.9 mg He and 1.8 mg N2
2.0 mg He and 0.13 mg N2
5.3 mg He and 0.22 mg N2
4.2 mg He and 8.7 mg N2
1.3 mg He and 4.2 mg N2
a.
b.
c.
d.
e.
1.63x10-2 M
1.63x10-4 M
1.63x10-6 M
1.63x10-7 M
None of the above
23. (6 points) A recent analysis of drinking water in central Ohio revealed the
presence of chloroform (CHCl3) at a concentration of 19.5 ppb (parts per billion).
What is the molarity of chloroform at 20˚C if the water sample has a density of
0.9983 g/mL at 20˚C?
6
24. (6 points) Concentrated hydriodic acid, HI (aq.), is 47.0% HI by mass and has a
density of 1.50 g/mL. What is the MOLARITY and MOLALITY of this solution?
a.
b.
c.
d.
e.
5.52 M, 3.67 m
5.52 M, 6.93 m
10.4 M, 3.67 m
10.4 M, 6.93 m
2.45 M, 6.93 m
25. (6 points) The vapor pressure of pure carbon tetrachloride (CCl4) at 65°C is 531
mm Hg. 20.0 g of a non-volatile, non-electrolyte but otherwise unknown solute is
added to 154.0 g of CCl4 at 65°C, which reduces the vapor pressure by 27 mm Hg.
What is the molecular weight of the solute?
a.
b.
c.
d.
e.
343 g/mol
359 g/mol
374 g/mol
399 g/mol
415 g/mol
a.
b.
c.
d.
e.
0.138 atm
0.132 atm
0.125 atm
0.117 atm
0.107 atm
a.
b.
c.
d.
e.
1.00 mol NaCl in 2.25 kg water
2.00 mol Na2SO4 in 4.50 kg water
0.500 mol CaCl2 in 1.75 kg water
0.250 mol Mg(OH)2 in 1.00 kg water
None of the above
26. (7 points) A solution at 0°C consists of 40.0 g of CH2Cl2 and 60.0 g of CH2Br2. The
vapor pressures of pure CH2Cl2 and CH2Br2 are 0.175 atm and 0.015 atm
respectively at 0˚C. What is the total pressure of the vapor above the solution?
27. (6 points) Which electrolytic solution has a LOWER freezing point than 1.0 mol
of glucrose (C6H12O6, non-electrolyte) in 1.00 kg water?
7
28. (6 points) What is the freezing point of a solution of 0.640 g of azulene (C10H8) in
100.0 g of camphor (C10H16O)? The molal freezing point constant of camphor is
40.0˚C/m and its freezing point is 179.75˚C.
a.
b.
c.
d.
e.
176.85 ˚C
177.75 ˚C
178.25 ˚C
181.75 ˚C
182.25˚C
a.
b.
c.
d.
e.
1.02 x 103 g/mol
1.39 x 103 g/mol
1.06 x 105 g/mol
1.39 x 104 g/mol
1.06 x 107 g/mol
29. (6 points) Lysozyme is an enzyme that cleaves cell walls. A 0.100 L aqueous
solution of lysozyme that contains 75.0 mg of the enzyme has an osmotic
pressure of 1.00 torr at 25°C. What is the molecular weight of lysozyme?
8
Useful information:
760 mmHg = 760 torr = 1 atm = 1.01325 bar = 101,325 Pa = 101.325 kPa =
14.696 psi
NA = 6.022x1023, R = 0.08206 L-atm/mol-K = 8.314 J/mol-K
T(K) = T(°C) + 273.15
1 inch= 2.54 cm, 1 nm = 10-9 m, 1 pm = 10-12 m
N = kg-m/s2, Pa = N/m2, J = kg-m2/s2
P = F/A, F = ma

n 2a 
PV=nRT, d=m/V,  P + 2 (V − nb) = nRT
V 

v=
3RT
where v is rms speed
M
z2 = x2 + y2 (diagonal of right angle triangle), Vbox = l · w · h
Sgas = kHPgas
PA = XAP˚A
∆Tb = Kfm, ∆Tf = Kfm
Π = (n/V)RT
9