Question 1

The coordination number of sodium and chloride ions in the NaCl lattice,are,respectively:

Accepted Answer

A) 10 and 10 
B) 8 and 8 
C) 6 and 6 
D) 4 and 4 
E) None of these choices is correct. 
A) 10 and 10 
B) 8 and 8 
C) 6 and 6 
D) 4 and 4 
E) None of these choices is correct.

Question 2

The strongest intermolecular interactions between hydrogen fluoride (HF)molecules arise from

Accepted Answer

A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) ionic bonds. 
A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) ionic bonds.

Question 3

The strongest intermolecular interactions between hydrogen sulfide (H2S)molecules arise from

Accepted Answer

A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) disulfide linkages. 
A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) disulfide linkages.

Question 4

Octane has a vapor pressure of 40.torr at 45.1°C and 400.torr at 104.0°C.What is its heat of vaporization?

Accepted Answer

A) 39.0 kJ/mol 
B) 46.0 kJ/mol 
C) 590 kJ/mol 
D) 710 kJ/mol 
E) None of these choices is correct. 
A) 39.0 kJ/mol 
B) 46.0 kJ/mol 
C) 590 kJ/mol 
D) 710 kJ/mol 
E) None of these choices is correct.

Question 5

a.Name the two unit cells which occur in close packing of identical atoms.
b.Briefly explain how the two types of close-packed lattices of identical atoms differ,in terms of atomic arrangements.

Accepted Answer

a.face-centered cubic;hexagonal
b.Cubic

Question 6

A sample of octane in equilibrium with its vapor in a closed 1.0-L container has a vapor pressure of 50.0 torr at 45°C.The container's volume is increased to 2.0 L at constant temperature and the liquid/vapor equilibrium is reestablished.What is the vapor pressure?

Accepted Answer

A) > 50.0 torr 
B) 50.0 torr 
C) 25.0 torr 
D) The mass of the octane vapor is needed to calculate the vapor pressure. 
E) The external pressure is needed to calculate the vapor pressure. 
A) > 50.0 torr 
B) 50.0 torr 
C) 25.0 torr 
D) The mass of the octane vapor is needed to calculate the vapor pressure. 
E) The external pressure is needed to calculate the vapor pressure.

Question 7

Which of the following is true about kinetic energy,Ek,and potential energy,Ep,when ethyl alcohol at 40°C is compared with ethyl alcohol at 20°C?

Accepted Answer

A) Ek(40°
C) k(20°
C) ;Ep(40°
C)  $\approx$ Ep(20°
C)  
B) Ek(40°
C) > Ek(20°
C) ;Ep(40°
C)  $\approx$ Ep(20°
C)  
C) Ep(40°
C) p(20°
C) ;Ek(40°
C)  $\approx$ Ek(20°
C)  
D) Ep(40°
C) > Ep(20°
C) ;Ek(40°
C)   $\approx$ Ek(20°
C)  
E) Ep(40°
C) > Ep(20°
C) ;Ek(40°
C) > Ek(20°
C)  
A) Ek(40°
C) k(20°
C) ;Ep(40°
C)  $\approx$ Ep(20°
C)  
B) Ek(40°
C) > Ek(20°
C) ;Ep(40°
C)  $\approx$ Ep(20°
C)  
C) Ep(40°
C) p(20°
C) ;Ek(40°
C)  $\approx$ Ek(20°
C)  
D) Ep(40°
C) > Ep(20°
C) ;Ek(40°
C)   $\approx$ Ek(20°
C)  
E) Ep(40°
C) > Ep(20°
C) ;Ek(40°
C) > Ek(20°
C)

Question 8

When the electron cloud of a molecule is easily distorted,the molecule has a high

Accepted Answer

A) polarity. 
B) polarizability. 
C) dipole moment. 
D) van der Waals radius. 
E) compressibility. 
A) polarity. 
B) polarizability. 
C) dipole moment. 
D) van der Waals radius. 
E) compressibility.

Question 9

Which of the following should have the highest surface tension at a given temperature?

Accepted Answer

A) a 
B) b 
C) c 
D) d 
E) e 
A) a 
B) b 
C) c 
D) d 
E) e

Question 10

The maximum number of phases of a single substance which can coexist in equilibrium is two.

Accepted Answer

A) True 
 B)False

Question 11

The strongest intermolecular interactions between pentane (C5H12)molecules arise from

Accepted Answer

A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) carbon-carbon bonds. 
A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) carbon-carbon bonds.

Question 12

Only molecules which do not have dipole moments can experience dispersion forces.

Accepted Answer

A) True 
 B)False

Question 13

The strongest intermolecular interactions between ethyl alcohol (CH3CH2OH)molecules arise from

Accepted Answer

A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) carbon-oxygen bonds. 
A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) ion-dipole interactions. 
E) carbon-oxygen bonds.

Question 14

A single water molecule can participate in at most two hydrogen bonds at any instant.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following factors contributes to a low viscosity for a liquid?

Accepted Answer

A) low temperature 
B) spherical molecular shape 
C) hydrogen bonding 
D) high molecular weight 
E) high boiling point 
A) low temperature 
B) spherical molecular shape 
C) hydrogen bonding 
D) high molecular weight 
E) high boiling point

Question 16

Which of the following pairs is arranged with the particle of higher polarizability listed first?

Accepted Answer

A) Se2-,S2- 
B) I,I- 
C) Mg2+,Mg 
D) Br,I 
E) None of these choices is correct. 
A) Se2-,S2- 
B) I,I- 
C) Mg2+,Mg 
D) Br,I 
E) None of these choices is correct.

Question 17

Which one of the following quantities is generally not obtainable from a single heating or cooling curve of a substance,measured at atmospheric pressure?

Accepted Answer

A) melting point 
B) boiling point 
C) triple point 
D) heat of fusion 
E) heat of vaporization 
A) melting point 
B) boiling point 
C) triple point 
D) heat of fusion 
E) heat of vaporization

Question 18

Which one of the following statements about unit cells and packing in solids is incorrect?

Accepted Answer

A) In any unit cell of a solid crystal,each face of the cell must have an opposite face which is equal and parallel to it. 
B) The faces of a unit cell must all be at angles of 90° to each other. 
C) The coordination number of atoms in a close packed metal is 12. 
D) The packing efficiency in fcc structures is higher than in bcc structures. 
E) The packing efficiency in fcc and hcp structures is the same. 
A) In any unit cell of a solid crystal,each face of the cell must have an opposite face which is equal and parallel to it. 
B) The faces of a unit cell must all be at angles of 90° to each other. 
C) The coordination number of atoms in a close packed metal is 12. 
D) The packing efficiency in fcc structures is higher than in bcc structures. 
E) The packing efficiency in fcc and hcp structures is the same.

Question 19

When the adhesive forces between a liquid and the walls of a capillary tube are greater than the cohesive forces within the liquid

Accepted Answer

A) the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a convex meniscus. 
B) the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a concave meniscus. 
C) the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a convex meniscus. 
D) the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a concave meniscus. 
E) None of these will occur. 
A) the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a convex meniscus. 
B) the liquid level in a capillary tube will rise above the surrounding liquid and the surface in the capillary tube will have a concave meniscus. 
C) the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a convex meniscus. 
D) the liquid level in a capillary tube will drop below the surrounding liquid and the surface in the capillary tube will have a concave meniscus. 
E) None of these will occur.

Question 20

Examine the following phase diagram and identify the feature represented by point A.

Accepted Answer

A) melting point 
B) critical point 
C) triple point 
D) sublimation point 
E) boiling point 
A) melting point 
B) critical point 
C) triple point 
D) sublimation point 
E) boiling point

Exam 12: Intermolecular Forces: Liquids,solids,and Phase Changes

The coordination number of sodium and chloride ions in the NaCl lattice,are,respectively:

The strongest intermolecular interactions between hydrogen fluoride (HF)molecules arise from

The strongest intermolecular interactions between hydrogen sulfide (H2S)molecules arise from

Octane has a vapor pressure of 40.torr at 45.1°C and 400.torr at 104.0°C.What is its heat of vaporization?

a.Name the two unit cells which occur in close packing of identical atoms. b.Briefly explain how the two types of close-packed lattices of identical atoms differ,in terms of atomic arrangements.

A sample of octane in equilibrium with its vapor in a closed 1.0-L container has a vapor pressure of 50.0 torr at 45°C.The container's volume is increased to 2.0 L at constant temperature and the liquid/vapor equilibrium is reestablished.What is the vapor pressure?

Which of the following is true about kinetic energy,Ek,and potential energy,Ep,when ethyl alcohol at 40°C is compared with ethyl alcohol at 20°C?

When the electron cloud of a molecule is easily distorted,the molecule has a high

Which of the following should have the highest surface tension at a given temperature?

The maximum number of phases of a single substance which can coexist in equilibrium is two.

The strongest intermolecular interactions between pentane (C5H12)molecules arise from

Only molecules which do not have dipole moments can experience dispersion forces.

The strongest intermolecular interactions between ethyl alcohol (CH3CH2OH)molecules arise from

A single water molecule can participate in at most two hydrogen bonds at any instant.

Which of the following factors contributes to a low viscosity for a liquid?

Which of the following pairs is arranged with the particle of higher polarizability listed first?

Which one of the following quantities is generally not obtainable from a single heating or cooling curve of a substance,measured at atmospheric pressure?

Which one of the following statements about unit cells and packing in solids is incorrect?

When the adhesive forces between a liquid and the walls of a capillary tube are greater than the cohesive forces within the liquid

Examine the following phase diagram and identify the feature represented by point A.

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

The Properties of Solutions

The Main-Group Elements: Applying Principles of Bonding and Structure

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

The strongest intermolecular interactions between hydrogen sulfide (H₂S)molecules arise from

Which of the following is true about kinetic energy,E_k,and potential energy,E_p,when ethyl alcohol at 40°C is compared with ethyl alcohol at 20°C?

The strongest intermolecular interactions between pentane (C₅H₁₂)molecules arise from

The strongest intermolecular interactions between ethyl alcohol (CH₃CH₂OH)molecules arise from