Liquids and SolidsN–1
SECTION N: LIQUIDS AND SOLIDS
INDEX: N001LEVEL: (U)ANSWER: (A)KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (TF)
The equilibrium vapor pressure of a few liters of a liquid is dependent on . Use each response in a separate question. / The equilibrium vapor pressure of a few liters of a liquid is dependent on
(A)the temperature only.
(B)the mass of the liquid.
(C)the volume of the liquid.
(D)the surface area of the liquid.
INDEX: N002LEVEL: (U)ANSWER: (E)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (SA)
What affects the equilibrium vapor pressure of a liquid? / The vapor pressure of a given liquid depends on
(A)volume of the container.
(B)barometric pressure.
(C)partial pressure of oxygen in the air.
(D)relative humidity of the air.
(E)temperature.
INDEX: N003LEVEL: (U)ANSWER: (C)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (FR)
When is a liquid considered to be boiling? / A liquid is considered to be boiling when
(A)it begins to vaporize.
(B)its vapor pressure equals one atmosphere.
(C)its vapor pressure equals the pressure applied on the liquid.
(D)equilibrium between the liquid and vapor phase exists.
INDEX: N004LEVEL: (U)ANSWER: (C)
KEYWORDS: bonding
ALTERNATIVE FORMAT: (TF)
has a higher boiling point than . Use pairs of responses in separate questions. / Which substance has the highest boiling point?
(A)CH4(B)He(C)HF(D)Cl2
INDEX: N005LEVEL: (A)ANSWER: (C)
KEYWORDS: thermochemistry
ALTERNATIVE FORMAT: (FR)
Given the cooling curve of one gram of a pure liquid, what determines the length of the line AB?
/ Given the cooling curve of one gram of a pure liquid, the length of the line AB depends on
(A)the specific heat of the pure solid.
(B)the specific heat of the pure liquid.
(C)the heat of fusion of the pure substance.
(D)the melting point of the pure substance.
INDEX: N006LEVEL: (A)ANSWER: (A)
KEYWORDS:
ALTERNATIVE FORMAT: (TF)
The normal boiling point of SO2 is 263.1 K and that of NH3 is 239.7 K. At –40 °C it is most likely that . Use each response in a separate question. / The normal boiling point of SO2 is 263.1 K and that of NH3 is 239.7 K. At –40 °C which would you predict?
(A)Ammonia has the greater vapor pressure.
(B)Sulfur dioxide has the greater vapor pressure.
(C)The vapor pressures would be equal.
(D)The vapor pressure of NH3 is 760 mmHg.
(E)The relative vapor pressures are not predictable from the data given.
INDEX: N007LEVEL: (A)ANSWER: (A)
KEYWORDS: laboratory, equilibrium
ALTERNATIVE FORMAT: (SA)
The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. What are the normal boiling points of A and B?
/ The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. Select the choice that best indicates the degree of correctness of this statement: “The normal boiling point of liquid B is 78 °C.”
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N008LEVEL: (A)ANSWER: (D)
KEYWORDS: laboratory, equilibrium
ALTERNATIVE FORMAT: (SA)
The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. What are the vapor pressures of A and B at 50 °C?
/ The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. Select the choice that best indicates the degree of correctness of this statement:
“At 60 °C, the vapor pressure of liquid A is about
1000 mmHg.”
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N009LEVEL: (A)ANSWER: (C)
KEYWORDS: laboratory, equilibrium
ALTERNATIVE FORMAT: (FR)
The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. A student needs to know the freezing point of both liquids. Can this graph be used, and, if so, what are their respective freezing points? If the graph cannot be used, what additional information is needed?
/ The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. Select the choice that best indicates the degree of correctness of this statement: “The freezing point of liquid B is 8 °C.”
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N010LEVEL: (A)ANSWER: (A)
KEYWORDS: laboratory, equilibrium
ALTERNATIVE FORMAT: (SA)
The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. Under the same conditions of temperature, atmospheric pressure, and surface exposed, which liquid will evaporate faster?
/ The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. Select the choice that best indicates the degree of correctness of this statement: “Liquid A will evaporate faster than liquid B under the same conditions of temperature, atmospheric pressure, and surface exposed.”
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N011LEVEL: (A)ANSWER: (E)
KEYWORDS: laboratory, equilibrium
ALTERNATIVE FORMAT: (FR)
Discuss the significance of the graph in terms of the physical properties of A and B that can be discerned from the data.
/ The graph shows how the vapor pressure of liquid A and of liquid B change with the temperature. Select the choice that best indicates the degree of correctness of this statement:
“At 80 °C, the vapor pressure of liquid B is 1200 mmHg.”
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N012LEVEL: (A)ANSWER: (B)
KEYWORDS: periodic properties
ALTERNATIVE FORMAT: (TF)
will not conduct electric current in the liquid state. Use each response in a separate question.
/ Which will not conduct electric current in the liquid state?
(A)Atom A
(B)Atom C
(C)Atom D
(D)A compound between Atom D and Atom E
(E)A compound between Atom A and Atom E
INDEX: N013LEVEL: (A)ANSWER: (A)
KEYWORDS: laboratory, equilibrium
ALTERNATIVE FORMAT: (SA)
If the opposing pressure were reduced to 90 mmHg by means of a vacuum pump, at approximately what temperatures would water, normal propanol, and turpentine boil?
Vapor Pressure of Substances in mmHg
/ Which choice best indicates the degree of correctness of this statement? “Water at 50° C would boil if the opposing pressure were reduced to 90 mmHg by means of a vacuum pump.”
Vapor Pressure of Substances in mmHg
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because the data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N014LEVEL: (A)ANSWER: (B)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (SA)
What are the normal boiling points of normal propanol, water, and turpentine?
Vapor Pressure of Substances in mmHg
/ Which choice best indicates the degree of correctness of this statement? “The boiling point of normal propanol is
97 °C.”
Vapor Pressure of Substances in mmHg
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because the data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N015LEVEL: (A)ANSWER: (E)
KEYWORDS:
ALTERNATIVE FORMAT: (TF)
If two open vessels, one containing normal propanol and the other containing water, both at the same temperature, are placed side by side and, if the alcohol and the water each have the same surface area, it is reasonable to believe that the volume of normal propanol will diminish at the same rate as the water.
Vapor Pressure of Substances in mmHg
/ Which choice best indicates the degree of correctness of this statement? “If two open vessels, one containing normal propanol and the other containing water, both at the same temperature, are placed side by side and, if the alcohol and the water each have the same surface area, it is reasonable to believe that the volume of normal propanol will diminish at the same rate as the water.”
Vapor Pressure of Substances in mmHg
(A)The statement is true.
(B)The statement is probably true; additional data would be needed for a final decision.
(C)It is impossible to judge the statement because the data are insufficient.
(D)The statement is probably false; additional data would be needed for a final decision.
(E)The statement is false.
INDEX: N016LEVEL: (A)ANSWER: (D)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (SA)
Consider the phase diagram of a pure compound. Sketch a path that represents sublimation.
/ Consider the phase diagram of a pure compound. Which statement applies?
(A)The path AC represents sublimation.
(B)Following the path ABC the compound would first liquefy and then vaporize.
(C)If the compound is in state A, continued reduction of the pressure (at constant temperature) will cause it to melt.
(D)None of these statements is correct.
INDEX: N017LEVEL: (A)ANSWER: (B)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (SA)
For CO2, the critical temperature is 31.1 °C and the critical pressure is 73 atm. Under what conditions is it possible to liquefy CO2? / For CO2, the critical temperature is 31.1 °C and the critical pressure is 73 atm. These data imply that CO2 can be liquified at
(A)31.l °C and 72.0 atm.(C)32.0 °C and 73.0 atm.
(B)30.0 °C and 73.0 atm.(D)32.0 °C and 74.0 atm.
INDEX: N018LEVEL: (A)ANSWER: (B)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (SA)
Omit responses. / In the phase diagram, which transition represents the condensation of a gas to a liquid?
(A)B to A(B)D to B(C)C to D(D)A to D
INDEX: N019LEVEL: (A)ANSWER: (C)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (SA)
On this phase diagram, where are vapor and liquid in equilibrium?
/ Which point represents a liquid-vapor equilibrium in this phase diagram?
(A)A(B)B(C)C(D)D
INDEX: N020LEVEL: (A)ANSWER: (A)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (SA)
Omit responses. / According to the phase diagram for xenon, what change, if any, occurs as the pressure on a Xe sample is reduced from 760 mmHg to 1 mmHg at –l23 °C?
(A)solid to gas
(B)solid to liquid to gas
(C)liquid to gas
(D)no phase change
INDEX: N021LEVEL: (U)ANSWER: (D)
KEYWORDS: equilibrium, thermochemistry
ALTERNATIVE FORMAT: (TF)
At the melting point of ice, 0 °C at 1 atm pressure, . Use each response in a separate question. / At the melting point of ice, 0 °C at 1 atm pressure,
(A)no heat is required to melt ice.
(B)the vapor pressure of ice is greater than the vapor pressure of liquid water.
(C)water cannot freeze.
(D)the solid and liquid states of water can coexist.
(E)a piece of ice in a thermos bottle turns to water.
INDEX: N022LEVEL: (A)ANSWER: (B)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (FR)
The graph (not drawn to scale) illustrates the pressure–temperature relations for water.
What are the effects of (1) decreasing the temperature at constant pressure and (2) decreasing the pressure at constant temperature on a sample of liquid water? / The graph (not drawn to scale) illustrates the pressure–temperature relations for water.
The areas labeled indicate the presence of only one phase, whereas the lines represent equilibrium states between the two adjoining phases. From this graph determine which of the following statements is true.
(A)Increasing the temperature decreases the vapor pressure of liquid water.
(B)Decreasing the temperature decreases the vapor pressure of ice.
(C)Decreasing the pressure increases the boiling point of pure water.
(D)Increasing the pressure increases the freezing point of pure ice.
(E)From the point of intersection of the three curves, decreasing the pressure will cause the formation of a liquid.
INDEX: N023LEVEL: (A)ANSWER: (C)
KEYWORDS: laboratory, equilibrium
ALTERNATIVE FORMAT: (FR)
A pure substance, above its melting point, is in a high pressure cylinder. Upon opening a valve on the cylinder a gas escapes. A pressure gauge on the cylinder shows a pressure of 56.5 atm. at 20 °C before opening the valve. After removing 10 ft3 of the gas, measured at standard conditions, the pressure in the cylinder reads 56.5 atm at
20 °C. The pressure gauge is in good working order. How can these observations be explained? / A pure substance, above its melting point, is in a high pressure cylinder. Upon opening a valve on the cylinder a gas escapes. A pressure gauge on the cylinder shows a pressure of 56.5 atm. at 20 °C before opening the valve. After removing 10 ft3 of the gas, measured at standard conditions, the pressure in the cylinder reads 56.5 atm at
20 °C. The pressure gauge is in good working order. Which best explains these observations?
(A)The cylinder and contents will weigh the same before and after opening the valve.
(B)The substance in the cylinder is in the gaseous state.
(C)The substance in the cylinder is mostly in the liquid state.
(D)The substance in the cylinder has diatomic molecules when in the gaseous state.
(E)The substance in the cylinder is oxygen.
INDEX: N024LEVEL: (U)ANSWER: (D)
KEYWORDS: equilibrium
ALTERNATIVE FORMAT: (TF)
A gas or vapor may be liquefied only at temperatures . Use each response in a separate question. / A gas or vapor may be liquefied only at temperatures
(A)equal to the normal boiling point.
(B)at or below the normal boiling point.
(C)above the normal boiling point.
(D)at or below the critical temperature.
(E)above the critical temperature.
INDEX: N025LEVEL: (A)ANSWER: (C)
KEYWORDS: introductory concepts, molecular geometry
ALTERNATIVE FORMAT: (SA)
Omit responses. / The edge of a unit cube of an element Y, containing two atoms per unit cube, was found (by X–ray diffraction) to be 3.16 10–8 cm. The density of the metal is 19.35 g·cm–3. What is the approximate atomic molar mass of Y?
(A)65.4(B)92.0(C)184(D)238
INDEX: N026LEVEL: (U)ANSWER: (A)
KEYWORDS: bonding
ALTERNATIVE FORMAT: (TF)
has a crystal structure containing discrete molecules. Use each response in a separate question. / Which one of these solid substances has a crystal structure containing discrete molecules?
(A)dry ice(C)quartz
(B)graphite(D)silver bromide
INDEX: N027LEVEL: (U)ANSWER: (B)
KEYWORDS: molecular geometry
ALTERNATIVE FORMAT: (SA)
Omit responses. / What is the number of closest neighbors in a body–centered cubic lattice?
(A)12(B)8(C)6(D)4
INDEX: N028LEVEL: (A)ANSWER: (A)
KEYWORDS: bonding, laboratory
ALTERNATIVE FORMAT: (TF)
is a cubic solid, a poor electrical conductor in the solid state, and a good conductor when fused. Use each response in a separate question. / Which substance meets the requirements: cubic solid; poor electrical conductor in the solid state; good conductor when fused?
(A)sodium chloride(C)diamond
(B)sulfur(D)chromium
INDEX: N029LEVEL: (U)ANSWER: (C)
KEYWORDS: molecular geometry, bonding
ALTERNATIVE FORMAT: (SA)
Omit responses. / How many nearest neighboring sodium ions does each chloride ion have in NaCl(s)?
(A)1(B)4(C)6(D)8
INDEX: N030LEVEL: (U)ANSWER: (B)
KEYWORDS: molecular geometry, introductory concepts
ALTERNATIVE FORMAT: (SA)
Omit responses. / The number of vertices (corners) and the number of faces on an octahedron are
(A)6 and 6(C)8 and 8
(B)6 and 8(D)l2 and 8
INDEX: N031LEVEL: (U)ANSWER: (C)
KEYWORDS: molecular geometry
ALTERNATIVE FORMAT: (SA)
A particular compound has a crystal lattice with a cubic unit cell with atoms A in the corner positions and atoms B in the body–centered position. What is the simplest formula for the compound? / A particular compound has a crystal lattice with a cubic unit cell with atoms A in the corner positions and atoms B in the body–centered position. The simplest formula for the compound is
(A)A4B(B)A2B(C)AB(D)A8B
INDEX: N032LEVEL: (U)ANSWER: (B)
KEYWORDS: molecular geometry
ALTERNATIVE FORMAT: (SA)
Omit responses. / When calculating the number of atoms in a unit cell, a given atom may be shared by neighboring unit cells. Calculate the effective number of atoms in a face–centered cubic unit cell of a metallic crystal.
(A)2(B)4(C)8(D)14
INDEX: N033LEVEL: (U)ANSWER: (C)
KEYWORDS: bonding
ALTERNATIVE FORMAT: (TF)
Carbon dioxide, CO2, in the form of dry ice would be classified as . Use each response in a separate question. / Carbon dioxide, CO2, in the form of dry ice would be classified as
(A)an ionic solid.(C)a molecular solid.
(B)a polymeric solid.(D)a metallic solid.
INDEX: N034LEVEL: (A)ANSWER: (C)
KEYWORDS: laboratory
ALTERNATIVE FORMAT: (TF)
Two pure substances, A and B, each melt at 87.5 °C. An unknown pure substance X also melts at 87.5 °C. Melting points are obtained on mixtures of X + A, X + B, and
A + B, and in each case the melting point of the mixture is below 87.5 °C. Therefore, . Use each response in a separate question. / Two pure substances, A and B, each melt at 87.5 °C. An unknown pure substance X also melts at 87.5 °C. Melting points are obtained on mixtures of X + A, X + B, and
A + B, and in each case the melting point of the mixture is below 87.5 °C. Therefore,
(A)X is the same as A but different from B.
(B)X, A and B are all the same.
(C)X is different from both A and B.
(D)A and B are the same, but X is different.
INDEX: N035LEVEL: (U)ANSWER: (B)
KEYWORDS: molecular geometry
ALTERNATIVE FORMAT: (SA)
Omit responses. / How many atoms are in a unit cell of a body-centered crystal?
(A)one(B)two(C)three(D)four
INDEX: N036LEVEL: (U)ANSWER: (E)
KEYWORDS: bonding, periodic properties
ALTERNATIVE FORMAT: (TF)
Anion–anion contact is more likely to occur in a crystal of than in a crystal of . Use pairs of responses in separate questions. / Anion–anion contact is most likely to occur in a crystal of
(A)LiF(B)RbF(C)KCl(D)CsI
(E)LiI
INDEX: N037LEVEL: (A)ANSWER: (E)
KEYWORDS: periodic properties, bonding, thermochemistry
ALTERNATIVE FORMAT: (TF)
When a hypothetical ionic crystal M+X– is heated, it vaporizes to form separate M+(g) and X–(g) ions. The energy required for this vaporization (the lattice energy) will be greatest when . Use each response in a separate question. / When a hypothetical ionic crystal M+X– is heated, it vaporizes to form separate M+(g) and X–(g) ions. The energy required for this vaporization (the lattice energy) will be greatest when
(A)the electron affinity of X is small in magnitude and the ionization potential of M is large in magnitude.
(B)the heat of vaporization of crystalline M is small.
(C)the heat of vaporization of crystalline M is large.
(D)the effective radii of M+ and X– are large.
(E)the effective radii of M+ and X– are small.
INDEX: N038LEVEL: (A)ANSWER: (C)