Question 1

If substance X has stronger intermolecular attractions than substance Y,which of the following is most apt to be false?

Accepted Answer

A)  Y has the lower boiling point and higher vapor pressure
B)  Y has the higher vapor pressure and lower molar heat of vaporization
C)  Y has the higher boiling point and higher molar heat of vaporization
D)  X has the higher boiling point and higher molar heat of vaporization
E)  X has the lower vapor pressure and higher molar heat of vaporization C

Question 2

Calculate the heat of fusion of an unknown pure substance if 5.33 × 103 kJ of heat is required to melt a 17.2 kg sample.

Accepted Answer

A)  1.09 × 10-5 J/g
B)  3.23 × 10-3 J/g
C)  3.10 × 102 J/g
D)  9.17 × 104 J/g
E)  3.10 × 105 J/g C

Question 3

Consider the open-ended manometer shown below.In this apparatus the arm on the right is open to the atmosphere and feels the full effect of atmospheric pressure.The pressure in the chemistry lab at the time of this experiment is 755 mm Hg.The flask contains O2,N2 and Ne.  Which of the following correctly applies to this apparatus?

Accepted Answer

A)   2,N2 and Ne.   Which of the following correctly applies to this apparatus? 
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E)  none of the above B

Question 4

Predict the order in which boiling points of the following hydrides decrease (highest boiling point first,lowest last): PH3,AsH3,SbH3 (As is atomic number 33; Sb is atomic number 51).

Accepted Answer

A)  PH3, AsH3, SbH3
B)  AsH3, SbH3, PH3
C)  SbH3, AsH3, PH3
D)  PH3, SbH3, AsH3
E)  SbH3, PH3, AsH3

Question 5

Acetone,a highly volatile liquid,is placed in an open container.The liquid disappears.The vapor pressure of the acetone in the open container...

Accepted Answer

A)  is higher than the equilibrium vapor pressure
B)  is lower than the equilibrium vapor pressure
C)  is the same as the equilibrium vapor pressure
D)  is equal to the vapor pressure of acetone in a closed container
E)  cannot be compared to the equilibrium vapor pressure without more information

Question 6

What is the total heat flow if 18 grams of water at 12°C is heated to become steam at 109°C? The specific heat of liquid water is 4.18 J/g • 0°C; the specific heat of steam is 2.0 J/g • 0°C.The heat of vaporization of water is 2.26 kJ/g,and the boiling point of water is 100°C.

Accepted Answer

A)  0.32 kJ
B)  6.6 kJ
C)  48 kJ
D)  41 kJ
E)  7.0 × 103 kJ

Question 7

How are network solids,such as diamond,C,and quartz,SiO2,distinguished from molecular crystals such as I2?

Accepted Answer

A)  Network solids have very high melting points
B)  Network solids are ionic, while molecular ones are covalent substances
C)  Network solids dissolve in water; molecular ones do not
D)  Network solids are excellent conductors of electricity, while molecular crystals are nonconductors
E)  Network solids have individual molecules of fixed size; molecular crystals do not

Question 8

Among the following,identify the sentence that states a fact about equilibrium vapor pressure,followed by an acceptable explanation or reason for the fact.

Accepted Answer

A)  Vapor pressure decreases with temperature because the liquid expands and molecules are farther apart
B)  Vapor pressure increases with temperature because intermolecular attractions are weaker at higher temperatures
C)  Vapor pressure decreases with temperature because molecules stick together better when they are hot
D)  Vapor pressure increases with temperature because energy is distributed more efficiently at higher temperatures
E)  Vapor pressure increases with temperature because at higher temperatures a larger fraction of the molecules has sufficient energy to escape from the liquid state

Question 9

Which of the following statements is correct?

Accepted Answer

A)  There is long-range order in a crystalline solid
B)  Graphite is an example of an amorphous solid.
C)  Glass, rubber, and plastic are examples of crystalline solids
D)  Particles in an amorphous solids are arranged in a distinct geometric order
E)  In a crystalline solid particles can move past the closest neighboring particles.

Question 10

Closed system A consists of liquid acetone in equilibrium with its own vapor at 30°C.System B is like System A,except that the volume of liquid,the area of the liquid surface,and the volume of the vapor space above the liquid are all twice as large as System A,and the temperature is only 15°C.Identify the statement among the following that is positively false.

Accepted Answer

A)  Evaporation and condensation rates are equal in A
B)  Evaporation and condensation rates are equal in B
C)  Evaporation rate in A is greater than evaporation rate in B
D)  Vapor pressure in B is greater than vapor pressure in A
E)  Condensation rate in A is greater than condensation rate in B

Question 11

Compared to a substance with induced dipole forces,a substance with hydrogen bond generally has:

Accepted Answer

A)  a higher normal boiling point and vapor pressure, but a lower heat of vaporization
B)  a lower normal boiling point, but higher vapor pressure and heat of vaporization
C)  higher heat of vaporization but lower normal boiling point and vapor pressure
D)  a lower normal boiling point and heat of vaporization, but higher vapor pressure
E)  lower vapor pressure, but higher normal boiling point and heat of vaporization

Question 12

A sample of solid silver releases 476 J of heat when cooled from 98.3°C to 21.2°C.The specific heat of silver is 0.24 J/g • °C.What is the mass of the sample?

Accepted Answer

A)  8.8 × 103 g
B)  1.5 × 105 g
C)  0.039 g
D)  1.5 g
E)  25.7 g

Question 13

Acetone,a highly volatile liquid,is placed in a closed container.The amount of liquid decreases,but eventually becomes stable.The volume of the closed space above the liquid is increased.The amount of liquid then...

Accepted Answer

A)  May or may not change, but no prediction can be made without additional information about temperature
B)  May or may not change, but no prediction can be made without additional information about the magnitude of the volume increase
C)  Remains the same
D)  Increases
E)  Decreases

Question 14

The graph below represents a temperature versus energy plot for a pure substance.Identify the point(s)...(i)where only liquid exists and (ii)is associated with the heat of vaporization

Accepted Answer

A)  (i)  7 (ii)  2 and 3
B)  (i)  7 (ii)  5 and 6
C)  (i)  4 (ii)  2 and 3
D)  (i)  4 (ii)  5 and 6
E)  (i)  1 (ii)  5 and 6

Question 15

Hydrogen gas can be collected by water displacement when magnesium reacts with hydrochloric acid.When the container is filled with the hydrogen gas,which of the following is true of the total pressure (P)inside the container?

Accepted Answer

A)   
B)   
C)   
D)   
E)  P = atmospheric pressure

Question 16

Which of the following statements is correct?

Accepted Answer

A)  Intermolecular forces are weaker in liquids than in gases because the particles are closer to each other
B)  Smaller intermolecular distances in liquids result in stronger intermolecular forces, when compared to intermolecular distances and forces in gases
C)  Compared to liquids, large distances between gaseous molecules yield large intermolecular attractions
D)  The smaller the distance between molecules the smaller the intermolecular attractions, therefore attractions are weaker in liquids than gases
E)  All statements are correct

Question 17

A sample of lead releases 221 kJ of heat when freezing.What is the mass of the sample? 
 Hfus = 23 J/g

Accepted Answer

A)  9.6 g
B)  9.6 × 103 g
C)  5.1 × 106 g
D)  2.0 × 10-7 g
E)  1.0 × 10-4 g

Question 18

What is the total heat flow if 27 grams of steam at 143°C is cooled to become water at 34°C? The specific heat of water is 4.18 J/g • °C; the specific heat of steam is 2.0 J/g • °C.The heat of vaporization of water is 2.26 kJ/g,and the boiling point of water is 100°C.

Accepted Answer

A)  2.3 kJ
B)  7.4 kJ
C)  61 kJ
D)  71 kJ
E)  9.8 × 103 kJ

Question 19

Calculate the heat of vaporization of zinc if 393 kJ is required to vaporize a 223-gram sample.

Accepted Answer

A)  1.14 × 10-5 kJ/g
B)  8.76 × 104 kJ/g
C)  0.567 kJ/g
D)  1.76 kJ/g
E)  2.26 kJ/g

Question 20

The main reason equilibrium vapor pressure is greater at higher temperatures is that...

Accepted Answer

A)  A larger fraction of the molecules in the sample has sufficient kinetic energy to move from the liquid phase to the vapor phase
B)  The average kinetic energy is greater
C)  Intermolecular attractions are weaker
D)  The particles are moving at higher speeds
E)  The escape energy is decreased

Exam 15: Gases, Liquids, and Solids

If substance X has stronger intermolecular attractions than substance Y,which of the following is most apt to be false?

Calculate the heat of fusion of an unknown pure substance if 5.33 × 10³ kJ of heat is required to melt a 17.2 kg sample.

Predict the order in which boiling points of the following hydrides decrease (highest boiling point first,lowest last) : PH₃,AsH₃,SbH₃ (As is atomic number 33; Sb is atomic number 51) .

Acetone,a highly volatile liquid,is placed in an open container.The liquid disappears.The vapor pressure of the acetone in the open container...

What is the total heat flow if 18 grams of water at 12°C is heated to become steam at 109°C? The specific heat of liquid water is 4.18 J/g • 0°C; the specific heat of steam is 2.0 J/g • 0°C.The heat of vaporization of water is 2.26 kJ/g,and the boiling point of water is 100°C.

How are network solids,such as diamond,C,and quartz,SiO₂,distinguished from molecular crystals such as I₂?

Among the following,identify the sentence that states a fact about equilibrium vapor pressure,followed by an acceptable explanation or reason for the fact.

Which of the following statements is correct?

Compared to a substance with induced dipole forces,a substance with hydrogen bond generally has:

A sample of solid silver releases 476 J of heat when cooled from 98.3°C to 21.2°C.The specific heat of silver is 0.24 J/g • °C.What is the mass of the sample?

Acetone,a highly volatile liquid,is placed in a closed container.The amount of liquid decreases,but eventually becomes stable.The volume of the closed space above the liquid is increased.The amount of liquid then...

The graph below represents a temperature versus energy plot for a pure substance.Identify the point(s) ...(i) where only liquid exists and (ii) is associated with the heat of vaporization

Hydrogen gas can be collected by water displacement when magnesium reacts with hydrochloric acid.When the container is filled with the hydrogen gas,which of the following is true of the total pressure (P) inside the container?

Which of the following statements is correct?

A sample of lead releases 221 kJ of heat when freezing.What is the mass of the sample? H_fus = 23 J/g

What is the total heat flow if 27 grams of steam at 143°C is cooled to become water at 34°C? The specific heat of water is 4.18 J/g • °C; the specific heat of steam is 2.0 J/g • °C.The heat of vaporization of water is 2.26 kJ/g,and the boiling point of water is 100°C.

Calculate the heat of vaporization of zinc if 393 kJ is required to vaporize a 223-gram sample.

The main reason equilibrium vapor pressure is greater at higher temperatures is that...

Exam 15: Gases, Liquids, and Solids

If substance X has stronger intermolecular attractions than substance Y,which of the following is most apt to be false?

Calculate the heat of fusion of an unknown pure substance if 5.33 × 103 kJ of heat is required to melt a 17.2 kg sample.

Predict the order in which boiling points of the following hydrides decrease (highest boiling point first,lowest last) : PH3,AsH3,SbH3 (As is atomic number 33; Sb is atomic number 51) .

Acetone,a highly volatile liquid,is placed in an open container.The liquid disappears.The vapor pressure of the acetone in the open container...

What is the total heat flow if 18 grams of water at 12°C is heated to become steam at 109°C? The specific heat of liquid water is 4.18 J/g • 0°C; the specific heat of steam is 2.0 J/g • 0°C.The heat of vaporization of water is 2.26 kJ/g,and the boiling point of water is 100°C.

How are network solids,such as diamond,C,and quartz,SiO2,distinguished from molecular crystals such as I2?

Among the following,identify the sentence that states a fact about equilibrium vapor pressure,followed by an acceptable explanation or reason for the fact.

Which of the following statements is correct?

Compared to a substance with induced dipole forces,a substance with hydrogen bond generally has:

A sample of solid silver releases 476 J of heat when cooled from 98.3°C to 21.2°C.The specific heat of silver is 0.24 J/g • °C.What is the mass of the sample?

Acetone,a highly volatile liquid,is placed in a closed container.The amount of liquid decreases,but eventually becomes stable.The volume of the closed space above the liquid is increased.The amount of liquid then...

The graph below represents a temperature versus energy plot for a pure substance.Identify the point(s) ...(i) where only liquid exists and (ii) is associated with the heat of vaporization

Hydrogen gas can be collected by water displacement when magnesium reacts with hydrochloric acid.When the container is filled with the hydrogen gas,which of the following is true of the total pressure (P) inside the container?

Which of the following statements is correct?

A sample of lead releases 221 kJ of heat when freezing.What is the mass of the sample? Hfus = 23 J/g

What is the total heat flow if 27 grams of steam at 143°C is cooled to become water at 34°C? The specific heat of water is 4.18 J/g • °C; the specific heat of steam is 2.0 J/g • °C.The heat of vaporization of water is 2.26 kJ/g,and the boiling point of water is 100°C.

Calculate the heat of vaporization of zinc if 393 kJ is required to vaporize a 223-gram sample.

The main reason equilibrium vapor pressure is greater at higher temperatures is that...

Calculate the heat of fusion of an unknown pure substance if 5.33 × 10³ kJ of heat is required to melt a 17.2 kg sample.

Predict the order in which boiling points of the following hydrides decrease (highest boiling point first,lowest last) : PH₃,AsH₃,SbH₃ (As is atomic number 33; Sb is atomic number 51) .

How are network solids,such as diamond,C,and quartz,SiO₂,distinguished from molecular crystals such as I₂?

A sample of lead releases 221 kJ of heat when freezing.What is the mass of the sample? H_fus = 23 J/g