Question 1

At a temperature of 27 K,neon condenses due to

Accepted Answer

A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) covalent bonding. 
E) intramolecular forces. 
A) dipole-dipole forces. 
B) London dispersion forces. 
C) hydrogen bonding. 
D) covalent bonding. 
E) intramolecular forces.

Question 2

The molar enthalpy of vaporization of boron tribromide is 30.5 kJ/mol,and its normal boiling point is 91°C.What is the vapor pressure of BBr3 at 20.°C? (R = 8.314 J/K • mol)

Accepted Answer

A) 11.5 torr 
B) 659 torr 
C) 255 torr 
D) 66.2 torr 
E) 167 torr 
A) 11.5 torr 
B) 659 torr 
C) 255 torr 
D) 66.2 torr 
E) 167 torr

Question 3

Which one of the following substances does not exist in the indicated solid type?

Accepted Answer

A) graphite-covalent crystals 
B) Na-metallic crystals 
C) SiO2-molecular crystals 
D) NaCl-ionic crystals 
E) diamond-covalent crystals 
A) graphite-covalent crystals 
B) Na-metallic crystals 
C) SiO2-molecular crystals 
D) NaCl-ionic crystals 
E) diamond-covalent crystals

Question 4

In a sample of hydrogen iodide,__________________ are the most important intermolecular forces.

Accepted Answer

A) dipole-dipole forces 
B) London dispersion forces 
C) hydrogen bonding 
D) covalent bonds 
E) polar covalent bonds 
A) dipole-dipole forces 
B) London dispersion forces 
C) hydrogen bonding 
D) covalent bonds 
E) polar covalent bonds

Question 5

Which of the following factors can contribute to the viscosity for a liquid?

Accepted Answer

A) Temperature 
B) Hydrogen bonding 
C) Molecular entanglements 
D) London forces 
E) All of the answers are correct. 
A) Temperature 
B) Hydrogen bonding 
C) Molecular entanglements 
D) London forces 
E) All of the answers are correct.

Question 6

Which of the responses includes all of the following that can form hydrogen bonds with water molecules? I.Na+,II.CH3COOH,III.C2H6,IV.CH3NH2

Accepted Answer

A) I and II 
B) I and III 
C) II and III 
D) II and IV 
E) III and IV 
A) I and II 
B) I and III 
C) II and III 
D) II and IV 
E) III and IV

Question 7

Which has the highest surface tension at room temperature?

Accepted Answer

A) CH4 
B) CF4 
C) CCl4 
D) CBr4 
E) CI4 
A) CH4 
B) CF4 
C) CCl4 
D) CBr4 
E) CI4

Question 8

Identify the dominant (strongest)type of intermolecular force present in NH3(l).

Accepted Answer

Question 9

If a molecule at the surface of a liquid has enough kinetic energy to escape the liquid phase and enter the gas phase,then which of the following terms is used to describe this phenomenon?

Accepted Answer

A) Boiling point 
B) Condensation 
C) Vaporization 
D) Sublimation 
E) Gasification 
A) Boiling point 
B) Condensation 
C) Vaporization 
D) Sublimation 
E) Gasification

Question 10

Molecular crystals are held together by the intermolecular forces of dispersion and dipole-dipole forces and by hydrogen bonding.

Accepted Answer

A) True 
 B)False

Question 11

Liquid sodium can be used as a heat transfer fluid.Its vapor pressure is 40.0 torr at 633°C and 400.0 torr at 823°C.What is its heat of vaporization?

Accepted Answer

A) 43.4 kJ/mol 
B) 52.5 kJ/mol 
C) 70.6 kJ/mol 
D) 1.00 × 102 kJ/mol 
E) 3.64 kJ/mol 
A) 43.4 kJ/mol 
B) 52.5 kJ/mol 
C) 70.6 kJ/mol 
D) 1.00 × 102 kJ/mol 
E) 3.64 kJ/mol

Question 12

Helium atoms do not combine to form He2 molecules,yet He atoms do attract one another weakly through

Accepted Answer

A) dipole-dipole forces. 
B) ion-dipole forces. 
C) dispersion forces. 
D) dipole-induced dipole forces. 
E) hydrogen bonding. 
A) dipole-dipole forces. 
B) ion-dipole forces. 
C) dispersion forces. 
D) dipole-induced dipole forces. 
E) hydrogen bonding.

Question 13

Krypton has a higher melting point than argon because of its

Accepted Answer

A) hydrogen bonding. 
B) stronger dispersion forces. 
C) permanent dipole moment. 
D) ionic bonds. 
E) greater ionization energy. 
A) hydrogen bonding. 
B) stronger dispersion forces. 
C) permanent dipole moment. 
D) ionic bonds. 
E) greater ionization energy.

Question 14

Based on the phase diagram of a pure substance given below,what is the significance of the point labeled B?

Accepted Answer

A) It is the normal melting point. 
B) It is the triple point. 
C) It is the critical point. 
D) It is the normal sublimation point. 
E) It is the normal boiling point. 
A) It is the normal melting point. 
B) It is the triple point. 
C) It is the critical point. 
D) It is the normal sublimation point. 
E) It is the normal boiling point.

Question 15

The atomic planes in a graphite crystal are separated by 335 pm.At what angle would you find the first-order (n = 1)diffraction of 0.154-nm X rays from a graphite crystal?

Accepted Answer

A) 27.4° 
B) 66.8° 
C) 0.232° 
D) 13.3° 
E) 38.0° 
A) 27.4° 
B) 66.8° 
C) 0.232° 
D) 13.3° 
E) 38.0°

Question 16

Which one of the following substances crystallizes as a molecular solid?

Accepted Answer

A) KI 
B) SiO2 
C) Sn 
D) CH3OH 
E) Al2(SO4)3 
A) KI 
B) SiO2 
C) Sn 
D) CH3OH 
E) Al2(SO4)3

Question 17

For the solid forms of the following elements,which one is most likely to be of the molecular type?

Accepted Answer

A) Cs 
B) C 
C) Pb 
D) S 
E) Cr 
A) Cs 
B) C 
C) Pb 
D) S 
E) Cr

Question 18

a.State the essential requirements for hydrogen bonding to be important in a compound.
b.List four properties of water which are significantly influenced by the presence of hydrogen bonding.
a.The compound must contain hydrogen bonded to an atom which is small,electronegative,and has lone pairs of electrons.The atoms which meet these criteria are N,O,and F.

Accepted Answer

b.High specific heat capacity;

Question 19

Identify the dominant (strongest)type of intermolecular force present in Cl2(l).

Accepted Answer

Question 20

One of the crystalline forms of zinc oxide is a structure where the oxygen atoms are at the lattice points in a face-centered cubic lattice.How many atoms are in each unit cell?

Accepted Answer

A) 2 
B) 4 
C) 6 
D) 8 
E) 10 
A) 2 
B) 4 
C) 6 
D) 8 
E) 10

Exam 11: Intermolecular Forces and the Physical Properties of Liquids and Solids

At a temperature of 27 K,neon condenses due to

The molar enthalpy of vaporization of boron tribromide is 30.5 kJ/mol,and its normal boiling point is 91°C.What is the vapor pressure of BBr3 at 20.°C? (R = 8.314 J/K • mol)

Which one of the following substances does not exist in the indicated solid type?

In a sample of hydrogen iodide,__________________ are the most important intermolecular forces.

Which of the following factors can contribute to the viscosity for a liquid?

Which of the responses includes all of the following that can form hydrogen bonds with water molecules? I.Na+,II.CH3COOH,III.C2H6,IV.CH3NH2

Which has the highest surface tension at room temperature?

Identify the dominant (strongest)type of intermolecular force present in NH3(l).

If a molecule at the surface of a liquid has enough kinetic energy to escape the liquid phase and enter the gas phase,then which of the following terms is used to describe this phenomenon?

Molecular crystals are held together by the intermolecular forces of dispersion and dipole-dipole forces and by hydrogen bonding.

Liquid sodium can be used as a heat transfer fluid.Its vapor pressure is 40.0 torr at 633°C and 400.0 torr at 823°C.What is its heat of vaporization?

Helium atoms do not combine to form He2 molecules,yet He atoms do attract one another weakly through

Krypton has a higher melting point than argon because of its

Based on the phase diagram of a pure substance given below,what is the significance of the point labeled B?

The atomic planes in a graphite crystal are separated by 335 pm.At what angle would you find the first-order (n = 1)diffraction of 0.154-nm X rays from a graphite crystal?

Which one of the following substances crystallizes as a molecular solid?

For the solid forms of the following elements,which one is most likely to be of the molecular type?

Identify the dominant (strongest)type of intermolecular force present in Cl2(l).

One of the crystalline forms of zinc oxide is a structure where the oxygen atoms are at the lattice points in a face-centered cubic lattice.How many atoms are in each unit cell?

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The molar enthalpy of vaporization of boron tribromide is 30.5 kJ/mol,and its normal boiling point is 91°C.What is the vapor pressure of BBr₃ at 20.°C? (R = 8.314 J/K • mol)

Which of the responses includes all of the following that can form hydrogen bonds with water molecules? I.Na⁺,II.CH₃COOH,III.C₂H₆,IV.CH₃NH₂

Identify the dominant (strongest)type of intermolecular force present in NH₃(l).

Helium atoms do not combine to form He₂ molecules,yet He atoms do attract one another weakly through

Identify the dominant (strongest)type of intermolecular force present in Cl₂(l).