General Chemistry PHS 1015 Practice Exam 4
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which of the following statements about pressure is FALSE?
A) Pressure is caused by gas molecules colliding with surfaces.
B) The atmosphere has a pressure as the components of air collide with surfaces.
C) After creating a pressure difference, the atmospheric pressure can push liquid up a straw.
D) A deep well dug in the ground must have the pump located at the bottom of well in order to
have the water come to the surface.
E) All of the above statements are true.
1)
2) Which of the following is NOT part of the Kinetic Molecular Theory?
A) Gas particles do not repel each other.
B) There is a large distance between gas particles as compared to their relative size.
C) The size of the actual gas particles is small compared to the volume of the whole gas.
D) The average energy of the particles is dependent on the molecular mass of the particle.
E) All of the above statements are part of the Kinetic Molecular Theory.
2)
3) Which of following statements are consistent with the Kinetic Molecular Theory?
A) Gases are compressible because the volume taken up by the gas is almost entirely open space.
B) Gases assume the shape and volume of their container because they are in constant,
straight-line motion.
C) Gases have a low density because there is so much empty space between the particles.
D) Gas particles collide with each other and surfaces without losing any energy.
E) All of the above statements are consistent with the Kinetic Molecular Theory.
3)
4) All of the following statements are consistent with the kinetic molecular theory of gases EXCEPT:
A) The size of the gas molecules is negligible compared to the total volume of the gas.
B) The average kinetic energy of the molecules of a gas is proportional to the temperature of the
gas in kelvins.
C) The gas molecules collide with each other and with the surfaces around them.
D) Strong attractive forces hold the gas molecules together.
E) none of the above
4)
5) 1 atm is equal to:
A) 760 mm Hg.
B) 760 torr.
C) 101,325 Pa.
D) 14.7 psi.
E) all of the above
5)
6) 1 torr is equal to:
A) 760 mm Hg.
B) 1 mm Hg.
C) 1 Pa.
D) 14.7 psi.
E) all of the above
6)
1
7) A barometer uses mercury because:
A) it is a convenient, safe, lightweight material.
B) the density of mercury is very large which allows the barometer to be short.
C) it is the traditional substance used, water could be as easily used.
D) it is the only liquid metal at room temperature.
E) All of the above are true.
7)
8) What is the equivalent pressure of 0.905 atm in units of mm Hg?
A) 688
B) 840
C) 0.905
D) 13.3
E) none of the above
8)
9) What is the equivalent pressure of 1520 torr in units of atm?
A) 203,000
B) 380.
C) 2.00
D) 1520
E) none of the above
9)
10) What is the equivalent pressure of 760 torr in units of mm Hg?
A) 760
B) 1
C) 14.7
D) 29.92
E) none of the above
10)
11) What is the equivalent pressure of 968 mm Hg in units of atm?
A) 1.27 atm
B) 0.785 atm
C) 968 atm
D) 1.30 atm
E) none of the above
11)
12) Boyle's Law is expressed as:
1
A) V is proportional to
P
12)
B) P is proportional to V
1
C) V is proportional to
T
D) V is proportional to T
E) none of the above
2
13) To solve problems using Boyle's Law, which mathematical equation should be used?
P1
P2
=
A)
V1 V2
13)
B) P1 V1 = P2 V2
C)
V1 V2
=
P1
P2
D) P2 V1 = P1 V2
E) none of the above
14) One liter of a gas is in a sealed chamber containing a moveable piston. If the piston is moved so that
the volume of the gas is compressed to a volume of one-half liter, what will happen to the pressure
on the gas? (Assume the temperature is constant and no gas particles are lost.)
A) The pressure will remain the same.
B) The pressure will be half of the original value.
C) The pressure will be twice the original value.
D) It would be impossible to move the piston since gases are not compressible.
E) none of the above
14)
15) A balloon filled with 0.500 L of air at sea level is submerged in the water to a depth that produces a
pressure of 3.25 atm. What is the volume of the balloon at this depth?
A) 1.63 L
B) 0.154 L
C) 6.50 L
D) 0.615 L
E) none of the above
15)
16) Divers often inflate heavy duty balloons attached to salvage items on the sea floor. If a balloon is
filled to a volume of 3.00 L at a pressure of 2.50 atm, what is the volume of the balloon when it
reaches the surface?
A) 7.50 L
B) 1.20 L
C) 0.833 L
D) 5.50 L
E) none of the above
16)
17) The initial volume of a gas cylinder is 750.0 mL. If the pressure of a gas inside the cylinder changes
from 840.0 mm Hg to 360.0 mm Hg, what is the final volume the gas occupies?
A) 3.151 L
B) 630.0 mL
C) 1.750 L
D) 321.4 mL
E) none of the above
17)
3
18) Charles's Law is expressed as:
1
A) V is proportional to
P
18)
B) P is proportional to V
1
C) V is proportional to
T
D) V is proportional to T
E) none of the above
19) To solve problems using Charles's Law, which mathematical equation should be used?
V1 V2
=
A)
T1
T2
19)
B) T1 V1 = T2 V2
C)
P1
V2
=
P2
V1
D) P2 V1 = P1 V2
E) none of the above
20) Which one of the following is impossible for an ideal gas?
T1 1
1
=
(
)
A)
V2 T2 V1
B)
20)
V1 V2
=
T1
T2
T2
C) V2 = ( ) V1
T1
D) V1 T1 = V2 T2
E) none of the above
21) When must temperature values in gas law calculations be expressed in kelvin units?
A) only for Charles's law
B) only for the Ideal Gas law
C) only for the Combined Gas law
D) never
E) always
21)
22) A 5.00 liter balloon of gas at 25°C is cooled to 0°C. What is the new volume (liters) of the balloon?
A) 0 liters
B) 22.4 liters
C) 5.46 liters
D) 4.58 liters
E) none of the above
22)
4
23) A gas sample occupies 3.50 liters of volume at 20.°C. What volume will this gas occupy at 100°C
(reported to three significant figures)?
A) 0.224 L
B) 2.75 L
C) 4.46 L
D) 17.5 L
E) none of the above
23)
24) What is the final volume of a balloon that was initially 500.0 mL at 25°C and was then heated to
50°C?
A) 461 mL
B) 193 mL
C) 1.00 L
D) 542 mL
E) none of the above
24)
25) If the volume of a gas container at 32.0°C changes from 1.55 L to 755 mL, what will the final
temperature be?
A) 149°C
B) 353°C
C) 273°C
D) -124°C
E) none of the above
25)
26) What is the initial temperature of a gas if the volume changed from 1.00 L to 1.10 L and the final
temperature was determined to be 255.0°C?
A) 480°C
B) -41°C
C) 232°C
D) 207°C
E) none of the above
26)
27) A balloon originally had a volume of 0.439 L at 44°C and a pressure of 729 torr. To what
temperature must the balloon be cooled to reduce its volume to 378 mL if the pressure remained
constant?
A) 0°C
B) 38°C
C) 95°C
D) 273°C
E) none of the above
27)
28) Gas density can be calculated by dividing the mass of gas by its volume. If you took a balloon of
gas and then warmed the balloon in a sunny window, what can now be said about the density of
the gas in the balloon?
A) The gas density will remain the same.
B) The gas density will increase.
C) The gas density will decrease.
D) The density of gases is independent of temperature.
E) none of the above
28)
5
29) Which of the following statements is TRUE for gases?
1. The temperature of a gas is inversely proportional to its pressure.
2. The volume of a gas is directly proportional to the pressure in torr.
3. The pressure of a gas is due to collisions of the gas molecules.
A) 1 only
B) 2 only
C) 3 only
D) 1 and 2 only
E) 1 and 3 only
29)
30) What is the proper form of the combined gas law?
P 1 T1 P 2 T 2
=
A)
V1
V2
30)
B)
C)
V1 T1 V2 T2
=
P1
P2
P1 V1
T1
=
P2 V2
T2
D) P1 V1 T1 = P2V2 T2
E) none of the above
31) A certain volume of gas was confined in a rigid container. If the pressure of the gas sample in the
container was doubled, what happened to the temperature?
A) The Kelvin temperature decreased by one-half.
B) The Kelvin temperature doubled.
C) The Kelvin temperature increased four times.
D) The Kelvin temperature decreased one-third.
E) not enough information
31)
32) Suppose a balloon was released from the ground and rose to such a height that both the
atmospheric pressure and atmospheric temperature decreased. Which statement is TRUE?
A) Both the temperature and pressure changes act to increase the balloon's volume.
B) Both the temperature and pressure changes act to decrease the balloon's volume.
C) The temperature change acts to increase the balloon's volume.
D) The pressure change acts to decrease the balloon's volume.
E) none of the above
32)
33) If the initial pressure of a system was 1.00 atm and the volume was halved and the kelvin
temperature was tripled, what is the final pressure?
A) 2.00 atm
B) 0.667 atm
C) 1.50 atm
D) 6.00 atm
E) not enough information
33)
6
34) A 325 mL sample of gas is initially at a pressure of 721 torr and a temperature of 32°C. If this gas is
compressed to a volume of 286 mL and the pressure increases to 901 torr, what will be the new
temperature of the gas (reported to three significant figures in °C)?
A) 35.2°C
B) 335°C
C) 62.4°C
D) 215°C
E) none of the above
34)
35) A sample of helium gas initially at 37.0°C, 785 torr and 2.00 L was heated to 58.0°C while the
volume expanded to 3.24 L. What is the final pressure in atm?
A) 517
B) 0.681
C) 1.79
D) 3.21
E) none of the above
35)
36) What is the final volume of a 500.0 mL gas container that increased in temperature from 299 K to
333 K while the pressure increased from 1.00 atm to 1.54 atm?
A) 0.691 L
B) 2.77 L
C) 0.362 L
D) 1.45 L
E) none of the above
36)
37) What is the initial temperature (°C) of a system that has the pressure decreased by 10 times while
the volume increased by 5 times with a final temperature of 150 K?
A) 27
B) 75
C) -198
D) 300
E) none of the above
37)
38) Avogadro's Law is expressed as:
1
A) V is proportional to
n
38)
B) P is proportional to n
1
C) n is proportional to
T
D) V is proportional to n
E) none of the above
7
39) To solve problems using Avogadro's Law, which mathematical equation should be used?
n1 n2
=
A)
P1 P2
39)
B) n 1 V1 = n 2 V2
C)
V1 V2
=
n1
n2
D) P1 V1 = P2 V2
E) none of the above
40) What happens to the volume of a gas when you double the number of moles of gas while keeping
the temperature and pressure constant?
A) The volume is halved.
B) The volume doubles.
C) The volume decreases, but more information is needed.
D) The volume increases, but more information is needed.
E) none of the above
40)
41) How many moles of gas were added to a balloon that started with 2.3 moles of gas and a volume of
1.4 L given that the final volume was 7.2 L?
A) 9.5
B) 4.4
C) 12
D) 0.085
E) none of the above
41)
42) If each of the following gas samples have the same temperature and pressure, which sample has
the greatest volume?
A) 1 gram of O2
42)
B) 1 gram of Ar
C) 1 gram of H2
D) all have the same volume
E) not enough information
43) Which of the following gas law relationships is true?
A) V 1/P
B) V T
C) V n
D) all of the above are true
E) none of the above are true
43)
44) For an ideal gas, which of the following pairs of variables are inversely proportional to each other
(if all other factors remain constant)?
A) P, V
B) P, T
C) V, T
D) n, P
E) none of the above
44)
8
45) The ideal gas law is:
A) PV = nRT
nRT
B) P =
V
C) T =
PV
nR
D) V =
nRT
P
45)
E) All of the above are forms of the ideal gas law.
46) A sample of 0.255 mole of gas has a volume of 748 mL at 28°C. Calculate the pressure of this gas.
(R= 0.0821 L · atm / mol · K)
A) 8.42 atm
B) 0.784 atm
C) 0.00842 atm
D) 7.84 × 10-4 atm
46)
47) What is the pressure of a 3.00 L gas vessel that has 18.0 grams of helium at 25°C?
(R= 0.0821 L atm/ mol K)
A) 147 atm
B) 36.7 atm
C) 32.6 atm
D) 1.81 atm
E) none of the above
47)
48) What is the temperature (°C) of 2.48 moles of gas stored in a 30.0 L container at 1559 mm Hg?
(R= 0.0821 L atm/ mol K)
A) 302
B) 189
C) 29
D) -84
E) none of the above
48)
49) Which conditions can cause nonideal gas behavior by 1) decreasing the space between gas particles
or 2) by slowing gas particles so that interactions are significant?
A) 1) high pressure; 2) high temperature
B) 1) high pressure; 2) low temperature
C) 1) low pressure; 2) high temperature
D) 1) low pressure; 2) low temperature
E) none of the above
49)
50) A 3.76 g sample of a noble gas is stored in a 2.00 L vessel at 874 torr and 25°C. What is the noble
gas?
(R= 0.0821 L atm/ mol K)
A) He
B) Ne
C) Ar
D) Kr
E) not enough information
50)
E) none of the above
9
51) Which of the following diatomic elements would have a mass of 19.08 grams stored in a 3.82 L
container at 3,632 mm Hg and 100°C? (R= 0.0821 L atm/ mol K)
A) H2
51)
B) Br2
C) F2
D) O2
E) not enough information.
52) What is the major component of the air we breathe?
A) nitrogen
B) oxygen
C) argon
D) carbon dioxide
E) smog
52)
53) What is the third most abundant component of dry air?
A) carbon dioxide
B) oxygen
C) nitrogen
D) argon
E) smog
53)
54) If a mixture of gases contained 78% nitrogen at a pressure of 984 torr and 22% carbon dioxide at
345 torr, what is the total pressure of the system?
A) 1,329 atm
B) 17.5 cm Hg
C) 639 torr
D) 1.75 atm
E) none of the above
54)
55) A gas cylinder contains only the gases radon, nitrogen, and helium. The radon has a pressure of 222
torr while the nitrogen has a pressure of 446 torr. If the total pressure inside the cylinder is 771 torr,
what is the pressure that is due to the helium?
A) 771 torr
B) 668 torr
C) 549 torr
D) 103 torr
E) none of the above
55)
56) A "shielding gas" mixture of argon and carbon dioxide is sometimes used in welding to improve
the strength of the weld. If a gas cylinder of this two-part mixture was at 4.0 atm pressure and this
mixture was 90.% argon, what would be the pressure due to the carbon dioxide gas component?
A) 3.6 atm
B) 0.40 atm
C) 10. atm
D) 4.0 atm
E) none of the above
56)
10
57) What problem could happen if deep sea divers used pure oxygen in their tanks?
A) hypoxia
B) oxygen toxicity
C) nitrogen narcosis
D) rapture of oxygen
E) none of the above
57)
58) Human lungs have evolved to breathe oxygen at a pressure as that in the atmosphere, 0.21 atm. If a
particular heliox mixture to be carried by a scuba diver is at a pressure of 7.00 atm, what should be
the partial pressure due to helium in order to maintain the pressure due to oxygen at 0.21 atm?
A) 0.21 atm
B) 7.00 atm
C) 6.79 atm
D) 7.21 atm
E) none of the above
58)
59) The vapor pressure of water at 20.0°C is 17.5 mm Hg. If the pressure of a gas collected over water
was measured to be 453.0 mm Hg. What is the pressure of the pure gas?
A) 0.0230 atm
B) 0.619 atm
C) 0.573 atm
D) 0.596 atm
E) none of the above
59)
60) Hydrogen gas produced in the laboratory by the reaction of zinc and hydrochloric acid was
collected over water at 25°C. The barometric pressure at the time was 742.5 mm Hg. What is the
pressure of dry hydrogen gas if the vapor pressure of water at 25°C is 23.8 mm Hg?
A) 742.5 mm Hg
B) 718.7 mm Hg
C) 766.3 mm Hg
D) 760.0 mm Hg
E) none of the above
60)
61) Suppose a chemical reaction generated a 50% nitrogen/50% oxygen (by volume) mixture of gas that
had a total volume of 22.4 liters at STP. This gas sample is composed of:
A) 1 mole of nitrogen and 1 mole of oxygen.
B) 0.5 mole of nitrogen and 0.5 mole of oxygen.
C) 50 mole of nitrogen and 50 mole of oxygen.
D) 28 mole of nitrogen and 32 mole of oxygen.
E) none of the above
61)
62) Which set of conditions reflect STP?
A) 298 K, 1 atm
B) 25°C, 14.7 psi
C) 373 K, 760 torr
D) 273 K, 1 Pa
E) 273 K, 760 mm Hg
62)
11
63) At STP, 12.69 g of a noble gas occupies 14.09 L. What is the identity of the noble gas?
(R= 0.0821 L atm/ mol K)
A) He
B) Ne
C) Ar
D) Kr
E) not enough information
63)
64) Suppose you had a balloon containing 1 mole of helium at STP and a balloon containing 1 mole of
oxygen at STP. Which statement is TRUE?
A) The balloons will have the same volume.
B) The balloons will have the same mass.
C) Both A) and B) are true.
D) Neither A) nor B) are true.
E) not enough information
64)
65) Ammonia gas decomposes according to the equation:
2NH3 (g) N2 (g) + 3H2 (g)
65)
66) Water can be formed according to the equation:
2H2 (g) + O2 (g) 2H2 O (g)
66)
67) How many liters of O2 (g) are needed to react completely with 56.0 L of CH4 (g) at STP to produce
67)
If 15.0 L of nitrogen is formed at STP, how many liters of hydrogen will be produced (also
measured at STP)?
A) 15.0 L
B) 30.0 L
C) 45.0 L
D) 90.0 L
E) not enough information
If 8.0 L of hydrogen is reacted at STP, exactly how many liters of oxygen at STP would be needed to
allow complete reaction?
A) 4.0 L
B) 2.0 L
C) 1.0 L
D) 8.0 L
E) none of the above
CO2 (g) and H2 O (g)?
Given: CH4 (g) + 2O2 (g)
A) 28.0 L
B) 56.0 L
C) 84.0 L
D) 112. L
E) none of the above
CO2 (g) + H2 O (g)
12
68) What is the pressure of 760 mm Hg when expressed in units of in Hg?
A) 29.92 in Hg
B) 101,325 in Hg
C) 760 in Hg
D) 1 in Hg
E) none of the above
68)
69) What is the final pressure of a system (atm) that has the volume increased from 0.75 L to 1.1 L with
an initial pressure of 1.25 atm?
A) 1.1
B) 0.85
C) 1.8
D) 1.2
E) none of the above
69)
70) What is the final volume (L) of a 10.0 L system that has the pressure quartered?
A) 0.250
B) 17.1
C) 2.50
D) 40.0
E) none of the above
70)
71) What is the final volume of a gas that initially occupies 2.50 L at 298 K and is subsequently heated
to 321 K?
A) 2.69 L
B) 2.96 L
C) 2.23 L
D) 2.32 L
E) none of the above
71)
72) What is the change in temperature of a 2.50 L system when its volume is reduced to 1.75 L if the
initial temperature was 298 K?
A) 209 K
B) 290 K
C) -89 K
D) -98 K
E) none of the above
72)
73) What is the final volume (L) of a 1.00 L system at 315 K and 1.10 atm if STP conditions are
established?
A) 1.05
B) 0.935
C) 1.50
D) 0.953
E) none of the above
73)
13
74) What is the final pressure (expressed in atm) of a 3.05 L system initially at 724 mm Hg and 298 K,
that is compressed to a final volume of 2.51 L at 273 K?
A) 1.06
B) 1.60
C) 806
D) 860
E) none of the above
74)
75) A rigid cylinder contains 2.00 liters of gas at a temperature of 25°C. If the pressure of this gas is
changed from 0.500 atmospheres to 1.50 atmospheres, what will be the new temperature (in Kelvin,
reported to three significant figures) of the gas? (The volume is constant.)
A) 99.3 K
B) 75.0 K
C) 8.33 K
D) 894 K
E) none of the above
75)
76) If the number of moles of a gas initially contained in a 2.10 L vessel is doubled, what is the final
volume of the gas in liters? (Assume the pressure and temperature remain constant.)
A) 6.30
B) 1.05
C) 4.20
D) 8.40
E) none of the above
76)
77) What is the volume (in liters) of 1.00 mole of krypton gas that has a pressure of 1140 mm Hg and a
temperature of 25.0°C? (R= 0.0821 L atm/ mol K)
A) 1.37
B) 16.3
C) 0.0215
D) 0.00180
E) none of the above
77)
78) What is the molecular weight of a gas if a 21.0 g sample has a pressure of 836 mm Hg at 25.0°C in a
2.00 L flask? (R= 0.0821 L atm/ mol K)
A) 243 amu
B) 1.89 amu
C) 234 amu
D) 11.1 amu
E) none of the above
78)
79) What is the pressure of a 1.0 L flask containing 0.60 g of He at 25°C? (R= 0.0821 L atm/ mol K)
A) 98 atm
B) 3.7 atm
C) 7.3 atm
D) 15 atm
E) none of the above
79)
14
80) What is the volume of 28.0 g of nitrogen gas at STP?
A) 33.6 L
B) 11.2 L
C) 22.4 L
D) 44.8 L
E) none of the above
80)
81) Intermolecular forces are responsible for:
A) the taste sensations.
B) the shape of protein molecules.
C) the function of DNA.
D) the existence of liquids and solids.
E) all of the above
81)
82) Which state of matter has a high density and an indefinite shape?
A) solids
B) liquids
C) gases
D) both solids and liquids
E) none of the above
82)
83) Which state of matter has a high density and a definite volume?
A) solids
B) liquids
C) gases
D) both solids and liquids
E) none of the above
83)
84) Which state of matter has a low density and an indefinite volume?
A) solids
B) liquids
C) gases
D) both solids and liquids
E) none of the above
84)
85) Which state of matter has a low density and is easily compressed?
A) solids
B) liquids
C) gases
D) both solids and liquids
E) none of the above
85)
86) Which statement about surface tension is FALSE?
A) Liquids tend to minimize their surface area.
B) Molecules on the surface of the liquid have fewer molecules to interact with.
C) Increased intermolecular forces increase surface tension.
D) Items with densities lower than water will sink due to surface tension.
E) All of the above statements are true.
86)
15
87) The tendency of a liquid to minimize its surface area is called:
A) capillary action.
B) viscosity.
C) surface tension.
D) vaporization.
E) none of the above
87)
88) The measure of the resistance to the flow of a liquid is called:
A) vapor pressure.
B) sublimation.
C) viscosity.
D) condensation.
E) none of the above
88)
89) The change of a substance from a liquid to a gaseous form is called:
A) dynamic equilibrium.
B) heat of fusion.
C) condensation.
D) vaporization.
E) volatile.
89)
90) A situation where two opposite processes are occurring at equal rates, and no net change is taking
place, is called:
A) vaporization.
B) condensation.
C) evaporation.
D) dynamic equilibrium.
E) none of the above
90)
91) Increasing the intermolecular forces of a liquid will do which of the following?
A) increase the viscosity
B) decrease the evaporation rate
C) increase the surface tension
D) decrease the vapor pressure
E) all of the above
91)
92) You can increase the vapor pressure of a liquid by:
A) increasing temperature.
B) increasing the viscosity.
C) establishing dynamic equilibrium.
D) using a nonvolatile compound.
E) all of the above
92)
93) Which statement about boiling point is FALSE?
A) The boiling point is higher for compounds with strong intermolecular forces.
B) The boiling point is higher for compounds with a high viscosity.
C) The boiling point of a compound is an absolute constant.
D) The boiling point of a compound is higher for nonvolatile compounds.
E) All of the above statements are true.
93)
16
94) Evaporation is:
A) increased by increasing temperature.
B) an endothermic process.
C) the opposite process to condensation.
D) a cooling process for humans when they sweat.
E) all of the above
94)
95) Which of the following statements is FALSE?
A) Evaporation is an endothermic process.
B) A puddle of water cools down as it evaporates.
C) As a liquid is converted into a gas, the liquid absorbs heat.
D) All of the above are true.
E) None of the above are true.
95)
96) The opposite process of freezing is:
A) evaporation.
B) sublimation.
C) boiling.
D) condensation.
E) none of the above
96)
97) The rate of vaporization of a liquid can be increased by:
1. increasing the surface area
2. increasing the temperature
3. increasing the strength of the intermolecular forces
A) 1 only
B) 2 only
C) 3 only
D) 1 and 2 only
E) 2 and 3 only
97)
98) Liquids that have high vapor pressure and low boiling points are called:
A) abnormal liquids.
B) volatile liquids.
C) non-volatile liquids.
D) viscous liquids.
E) none of the above
98)
99) The amount of heat required to melt one mole of a solid is called the:
A) heat of vaporization.
B) heat of fusion.
C) heating curve.
D) cooling curve.
E) none of the above
99)
17
100) Compare a small pot of water that is boiling vigorously to a large pot of water that is boiling gently.
Which statement is TRUE?
A) The small pot is boiling at higher temperature than the large pot.
B) The large pot is boiling at a higher temperature than the small pot.
C) Both pots are boiling at the same temperature.
D) The vapor pressure of the liquid is greater than the pressure above the pot in each case.
E) none of the above
100)
101) When sufficient quantity of heat has been added to reach the boiling point of a solution, what
happens to any additional heat added?
A) Additional heat is used to evaporate the liquid as the process is endothermic and requires
continued input of energy.
B) Additional heat raises the temperature of the liquid which in turn increases the rate at which
boiling occurs.
C) Additional heat lowers the intermolecular forces of the liquid which in turn increases the
volatility of the liquid.
D) Additional heat alters the viscosity and the surface tension of the liquid which raises the
vapor pressure and increases the boiling point which is why you must continually heat the
solution.
E) None of the above are correct statements.
101)
102) What is the heat of vaporization(kJ/mol) if it takes 3,452 J of heat to completely vaporize 2.68 moles
of the liquid at its boiling point?
A) 1288
B) 1.29
C) 0.776
D) 12.2
E) none of the above
102)
103) How many joules of heat are needed to completely vaporize 24.40 grams of water at its boiling
point?
Given Hvap = 40.6 kJ/mol
103)
A) 54.97
B) 5.50 × 104
C) 29.98
D) 3.00 × 104
E) none of the above
104) How many kilojoules of heat are needed to completely vaporize 42.8 grams of C4 H10O at its
boiling point?
Given Hvap = 26.5kJ/mol
A) 74.12
B) 9.49
C) 15.3
D) 16.3
E) none of the above
18
104)
105) What happens as you start to add heat to a solid substance?
A) Thermal energy causes the components of the solid to vibrate faster.
B) When the melting point is reached, the thermal energy is sufficient to overcome
intermolecular forces holding the components at their stationary points.
C) Increasing the rate of heating of a substance at its melting point only causes more rapid
melting.
D) If a liquid forms, continued heating results in increasing the liquid temperature.
E) all of the above
105)
106) If we supply additional heat to a solid in equilibrium with its liquid at the melting point, the
thermal energy added is used to:
A) overcome the intermolecular forces that hold the solid together.
B) expand the solid.
C) change the liquid back to solid.
D) change solid to liquid.
E) raise the temperature of the solid above its melting point.
106)
107) When you make ice cubes:
A) it is an endothermic process.
B) it is an exothermic process.
C) the heat of vaporization must be removed.
D) the process is referred to scientifically as sublimation.
E) none of the above
107)
108) Which statement is TRUE in describing what occurs when a solid melts to a liquid?
A) The process is endothermic and the heat of fusion is positive.
B) The process is endothermic and the heat of fusion is negative.
C) The process is exothermic and the heat of fusion is positive.
D) The process is exothermic and the heat of fusion is negative.
E) not enough information
108)
109) Gaseous water vapor can frost the windows of a car on a cold morning. This process of a gas
changing directly into a solid is known as:
A) deposition.
B) melting.
C) condensation.
D) sublimation.
E) none of the above
109)
110) Paradichlorobenzene, a material used in "moth balls," is known to go directly from a solid form to a
gaseous form. This process is known as:
A) melting
B) evaporation
C) condensation
D) boiling
E) sublimation
110)
19
111) How much energy does it take to melt a 16.87 g ice cube?
Hfus= 6.02 kJ/mol
111)
112) How many grams of C4 H10O can be melted by 2.00 × 103 J?
112)
113) In northern climates, it is common to have a layer of frost form on cars that have been out overnight
in the winter. During the day the frost layer disappears despite the temperature of the ice
remaining below freezing. How?
A) The frost melts due to the sun heating the surface of the car above the melting point.
B) The frost evaporates due to the sun heating the solid.
C) The frost cycles as does the saturation level of moisture in the winter air does from night to
day.
D) The frost sublimes directly from solid ice to water vapor.
E) none of the above
113)
114) Which intermolecular force is present in all molecules and atoms?
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) X-forces
E) none of the above
114)
115) Which intermolecular force is due to the formation of an instantaneous dipole?
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) X-forces
E) none of the above
115)
116) The ability of sodium chloride to mix with water is most likely due to:
A) dispersion force
B) ion-dipole force
C) dipole-dipole force
D) hydrogen bonding
E) none of the above
116)
A) 102 kJ
B) 108 kJ
C) 936 J
D) 5.64 kJ
E) none of the above
Given Hfus=7.27 kJ/mol
A) 14.5
B) 3.64
C) 20.4
D) 74.1
E) none of the above
20
117) Which substance below has dipole-dipole forces?
A) CH4
117)
B) CO2
C) F2
D) H2 S
E) none of the above
118) Which intermolecular force increases with increasing molar mass?
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) X-forces
E) none of the above
118)
119) Which noble gas has the highest boiling point?
A) He
B) Ne
C) Ar
119)
D) Kr
E) Xe
120) Assuming that the molecules carbon monoxide (CO) and nitrogen (N2 ) have similar electron
120)
clouds, which statement below is TRUE?
A) CO has the higher boiling point because it experiences dipole-dipole forces.
B) N2 has the higher boiling point because it experiences dipole-dipole forces.
C) The N2 has the higher boiling point because it has greater dispersion forces.
D) Both CO and N2 must have the same boiling point.
E) none of the above
121) Which intermolecular force is common to all polar molecules but NOT nonpolar molecules?
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) X-forces
E) none of the above
121)
122) Substance A is a molecular compound that dissolves in gasoline but not in water. The molecules of
A are very likely:
A) metallic.
B) nonmetallic.
C) polar.
D) nonpolar.
E) none of the above
122)
123) Which substance is most likely to be miscible with water?
A) CF4
123)
B) Br2
C) CS2
D) CHCl3
E) none of the above
21
124) Which statement below is FALSE?
A) A hydrogen bond is the strongest of the intermolecular forces.
B) A hydrogen atom must be bonded directly to fluorine, oxygen, or nitrogen to exhibit
hydrogen bonding.
C) The large electronegativity difference between hydrogen and an F, O, or N atom is essential
for the formation of a hydrogen bond.
D) A hydrogen bond is only 2-5% the strength of a typical covalent bond.
E) none of the above
124)
125) Which molecule below has hydrogen bonding?
A) CH4
125)
B) HCl
C) H2
D) CH3 CH2 OH
E) all of the above
126) Which molecule below has hydrogen bonding?
A) NH3
126)
B) CH3 OH
C) H2 O
D) HF
E) all of the above
127) Which compound in liquid form will have the highest vapor pressure?
A) CH4
127)
B) CH3 CH3
C) CH3 C(O)CH3
D) CH3 CH2 OH
E) not enough information
128) Which intermolecular force is the strongest?
A) dispersion force
B) dipole-dipole force
C) hydrogen bonding
D) ion-dipole force
E) none of the above
128)
129) Which intermolecular forces are found in CCl4 ?
129)
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) X-forces
E) none of the above
22
130) Which intermolecular forces are found in CO2 ?
130)
131) What types of forces exist between I2 molecules?
131)
132) Which intermolecular force found in CCl2 H2 is the strongest?
132)
133) Consider the three compounds below, then choose the compound(s) that have hydrogen bonding.
1) H2
133)
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) dispersion forces and dipole-dipole forces
E) none of the above
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) ion-dipole forces
E) none of the above
A) dispersion forces
B) dipole-dipole forces
C) hydrogen bonding
D) X-forces
E) none of the above
2) CH4
3) HF
A) Only compound 1 has hydrogen bonding.
B) Only compound 2 has hydrogen bonding.
C) Only compound 3 has hydrogen bonding.
D) All three of these compounds have hydrogen bonding.
E) None of these compounds have hydrogen bonding.
134) Which compound will have the highest boiling point?
A) CH4
134)
B) CH3 CH3
C) CH3 C(O)CH3
D) CH3 CH2 OH
E) not enough information
135) Which substance would be expected to have the highest boiling point?
A) N2
B) O2
C) CO2
D) CO
E) not enough information
23
135)
136) Rank the compounds NH3 , CH4, and PH3 in order of increasing boiling point.
136)
A) NH3 < CH4 < PH3
B) CH4 < NH3 < PH3
C) NH3 < PH3 < CH4
D) CH4 < PH3 < NH3
E) PH3 < NH3 < CH4
137) Dry ice (solid CO2 ) is which type of solid?
137)
138) Which substance below is an ionic solid?
A) Cu (s)
B) H2 O (s)
138)
139) NaCl is which type of solid?
A) molecular solid
B) ionic solid
C) covalent atomic solid
D) nonbonding atomic solid
E) metallic atomic solid
139)
140) Silicon is which type of solid?
A) molecular solid
B) ionic solid
C) covalent atomic solid
D) nonbonding atomic solid
E) metallic atomic solid
140)
141) Copper is which type of solid?
A) molecular solid
B) ionic solid
C) covalent atomic solid
D) nonbonding atomic solid
E) metallic atomic solid
141)
142) Which atomic solid has the highest melting point?
A) Cu
B) Si
C) Xe
D) Fe
E) not enough information
142)
A) molecular solid
B) ionic solid
C) covalent atomic solid
D) nonbonding atomic solid
E) metallic atomic solid
C) MgO (s)
D) C6 H12O6 (s)
E) none of the above
24
143) What are the principal forces holding ice together?
A) dispersion forces only
B) electrostatic attraction
C) intermolecular forces
D) sea of electrons
E) none of the above
143)
144) Why is water considered an unusual molecule?
A) No molecule of similar size is a liquid at room temperature.
B) No molecule of similar size has as high a boiling point.
C) Water can dissolve many polar and ionic compounds.
D) Water expands upon freezing.
E) all of the above
144)
145) The reason for many of the unique properties of water is:
A) dispersion forces.
B) the ability to form hydrogen bonds.
C) high surface tension and low volatility.
D) moderate viscosity and expanding upon freezing.
E) all of the above
145)
146) Which sequence correctly shows the increasing density of the three phases of water?
A) solid < liquid < gas
B) gas < liquid < solid
C) gas < solid < liquid
D) liquid < gas < solid
E) none of the above
146)
147) How many kJ of heat are needed to completely vaporize 3.30 moles of H2 O? The heat of
147)
148) How many kJ of heat are needed to completely vaporize 23.4 g of H2 O? The heat of vaporization
148)
149) A 250 gram sample of water at the boiling point had 45.0 kJ of heat added. How many grams of
water were vaporized? Heat of vaporization for water is 40.6 kJ/mole.
A) 1.11
B) 20.0
C) 0.902
D) 16.2
E) none of the above
149)
vaporization for water at the boiling point is 40.6 kJ/mole.
A) 12.3
B) 134
C) 67.0
D) 2.26
E) none of the above
for water at the boiling point is 40.6 kJ/mole.
A) 31.2
B) 52.8
C) 23.4
D) 2.26
E) none of the above
25
150) How many kJ of heat are needed to completely melt 1.70 moles of H2 O, given that the water is at
150)
151) How many kJ of heat are needed to completely melt 17.3 g of H2 O, given that the water is at its
151)
152) How many kJ of heat are needed to completely melt 95.3 g of copper metal, given that the metal is
at its melting point? The heat of fusion for this metal is 13.1 kJ/mole.
A) 19.6
B) 43.0
C) 1250
D) 0.114
E) none of the above
152)
its melting point? The heat of fusion for water is 6.02 kJ/mole.
A) 30.6
B) 10.2
C) 3.54
D) 63.7
E) none of the above
melting point? The heat of fusion for water is 6.02 kJ/mole.
A) 0.961
B) 5.79
C) 1.04
D) 6.26
E) none of the above
26
Answer Key
Testname: GENERAL CHEMISTRY PHS 1015 PRACTICE EXAM 4
1) E
2) D
3) E
4) D
5) E
6) B
7) B
8) A
9) C
10) A
11) A
12) A
13) B
14) C
15) B
16) A
17) C
18) D
19) A
20) D
21) E
22) D
23) C
24) D
25) D
26) D
27) A
28) C
29) C
30) C
31) B
32) E
33) D
34) C
35) B
36) C
37) A
38) D
39) C
40) B
41) A
42) C
43) D
44) A
45) E
46) A
47) B
48) C
49) B
50) C
27
Answer Key
Testname: GENERAL CHEMISTRY PHS 1015 PRACTICE EXAM 4
51) D
52) A
53) D
54) D
55) D
56) B
57) B
58) C
59) C
60) B
61) B
62) E
63) B
64) A
65) C
66) A
67) D
68) A
69) B
70) D
71) A
72) C
73) D
74) A
75) D
76) C
77) B
78) C
79) B
80) C
81) E
82) B
83) D
84) C
85) C
86) D
87) C
88) C
89) D
90) D
91) E
92) A
93) C
94) E
95) D
96) E
97) D
98) B
99) B
100) C
28
Answer Key
Testname: GENERAL CHEMISTRY PHS 1015 PRACTICE EXAM 4
101)
102)
103)
104)
105)
106)
107)
108)
109)
110)
111)
112)
113)
114)
115)
116)
117)
118)
119)
120)
121)
122)
123)
124)
125)
126)
127)
128)
129)
130)
131)
132)
133)
134)
135)
136)
137)
138)
139)
140)
141)
142)
143)
144)
145)
146)
147)
148)
149)
150)
A
B
B
C
E
D
B
A
A
E
D
C
D
A
A
B
D
A
E
A
B
D
D
E
D
E
A
D
A
A
A
B
C
D
D
D
A
C
B
C
E
B
C
E
B
C
B
B
B
B
29
Answer Key
Testname: GENERAL CHEMISTRY PHS 1015 PRACTICE EXAM 4
151) B
152) A
30