Question 1

What types of forces exist between molecules of CO2?

Accepted Answer

A) Hydrogen bonding only. 
B) Hydrogen bonding and dispersion forces. 
C) Dipole-dipole forces only. 
D) Dipole-dipole and dispersion forces. 
E) Dispersion forces only. 
A) Hydrogen bonding only. 
B) Hydrogen bonding and dispersion forces. 
C) Dipole-dipole forces only. 
D) Dipole-dipole and dispersion forces. 
E) Dispersion forces only.

Question 2

Diethyl ether, used as a solvent for extraction of organic compounds from aqueous solutions, has a high vapor pressure which makes it a potential fire hazard in laboratories in which it is used. How much energy is released when 100.0 g is cooled from 53.0°C to 10.0°C?

Accepted Answer

A) 10.1 kJ 
B) 13.1 kJ 
C) 16.1 kJ 
D) 45.2 kJ 
E) 48.6 kJ 
A) 10.1 kJ 
B) 13.1 kJ 
C) 16.1 kJ 
D) 45.2 kJ 
E) 48.6 kJ

Question 3

The phase diagram of a substance shows the energy changes associated with changes of state.

Accepted Answer

A) True 
 B)False

Question 4

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

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 5

Liquid crystal displays are most commonly constructed of smectic type liquid crystals.

Accepted Answer

A) True 
 B)False

Question 6

Examine the phase diagram for the substance Bogusium (Bo) and select the correct statement.

Accepted Answer

A) Bo( s)has a lower density than Bo( l). 
B) The triple point for Bo is at a higher temperature than the melting point for Bo. 
C) Bo changes from a solid to a liquid as one follows the line from C to D. 
D) Bo changes from a liquid to a gas as one follows the line from C to D. 
E) Point B represents the critical temperature and pressure for Bo. 
A) Bo( s)has a lower density than Bo( l). 
B) The triple point for Bo is at a higher temperature than the melting point for Bo. 
C) Bo changes from a solid to a liquid as one follows the line from C to D. 
D) Bo changes from a liquid to a gas as one follows the line from C to D. 
E) Point B represents the critical temperature and pressure for Bo.

Question 7

The phase diagram for xenon has a solid-liquid curve with a positive slope. Which of the following is true?

Accepted Answer

A) Solid xenon has a higher density than liquid xenon. 
B) Solid xenon has the same density as liquid xenon. 
C) The phase diagram cannot be used to predict which phase of xenon is denser. 
D) Freezing xenon is an endothermic process. 
E) None of these choices are correct. 
A) Solid xenon has a higher density than liquid xenon. 
B) Solid xenon has the same density as liquid xenon. 
C) The phase diagram cannot be used to predict which phase of xenon is denser. 
D) Freezing xenon is an endothermic process. 
E) None of these choices are correct.

Question 8

Hexagonal close packing of identical atoms occurs when close-packed layers are stacked in an abcabc... arrangement.

Accepted Answer

A) True 
 B)False

Question 9

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

Question 10

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

Accepted Answer

A) Melting point 
B) Triple point 
C) Critical point 
D) Sublimation point 
E) Boiling point 
A) Melting point 
B) Triple point 
C) Critical point 
D) Sublimation point 
E) Boiling point

Question 11

Select the pair of substances in which the one with the higher vapor pressure at a given temperature is listed first.

Accepted Answer

A) C 7H 16, C 5H 12 
B) CCl 4, CBr 4 
C) H 2O, H 2S 
D) CH 3CH 2OH, CH 3-O-CH 3 
E) Xe, Kr 
A) C 7H 16, C 5H 12 
B) CCl 4, CBr 4 
C) H 2O, H 2S 
D) CH 3CH 2OH, CH 3-O-CH 3 
E) Xe, Kr

Question 12

A liquid may be made to boil at room temperature, simply by lowering the pressure.

Accepted Answer

A) True 
 B)False

Question 13

Ceramic superconductors often contain copper in unusual oxidation states.

Accepted Answer

A) True 
 B)False

Question 14

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

Question 15

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 16

Lead crystallizes in the face-centered cubic lattice. What is the coordination number for Pb?

Accepted Answer

A) 4 
B) 6 
C) 8 
D) 10 
E) 12 
A) 4 
B) 6 
C) 8 
D) 10 
E) 12

Question 17

Which of the following statements about ceramics is incorrect?

Accepted Answer

A) Silicon carbide has a diamond-like structure. 
B) Boron nitride can exist in both diamond-like and graphite-like forms. 
C) Silicon carbide can be prepared by direct reaction of silicon and carbon. 
D) Superconducting ceramics present manufacturing difficulties owing to their brittleness. 
E) Superconducting ceramic compounds usually incorporate cobalt in a key role. 
A) Silicon carbide has a diamond-like structure. 
B) Boron nitride can exist in both diamond-like and graphite-like forms. 
C) Silicon carbide can be prepared by direct reaction of silicon and carbon. 
D) Superconducting ceramics present manufacturing difficulties owing to their brittleness. 
E) Superconducting ceramic compounds usually incorporate cobalt in a key role.

Question 18

In which of the following compounds will the molecules not form hydrogen bonds with each other?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 19

A metal with a body-centered cubic lattice will have __________ atom(s) per unit cell.

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 9 
A) 1 
B) 2 
C) 3 
D) 4 
E) 9

Question 20

Which of the following statements concerning a face-centered cubic unit cell and the corresponding lattice, made up of identical atoms, is incorrect?

Accepted Answer

A) The coordination number of the atoms in the lattice is 8. 
B) The packing in this lattice is more efficient than for a body-centered cubic system. 
C) If the atoms have radius r, then the length of the cube edge is √8 × r. 
D) There are four atoms per unit cell in this type of packing. 
E) The packing efficiency in this lattice and hexagonal close packing are the same. 
A) The coordination number of the atoms in the lattice is 8. 
B) The packing in this lattice is more efficient than for a body-centered cubic system. 
C) If the atoms have radius r, then the length of the cube edge is √8 × r. 
D) There are four atoms per unit cell in this type of packing. 
E) The packing efficiency in this lattice and hexagonal close packing are the same.

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

What types of forces exist between molecules of CO2?

Diethyl ether, used as a solvent for extraction of organic compounds from aqueous solutions, has a high vapor pressure which makes it a potential fire hazard in laboratories in which it is used. How much energy is released when 100.0 g is cooled from 53.0°C to 10.0°C?

The phase diagram of a substance shows the energy changes associated with changes of state.

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

Liquid crystal displays are most commonly constructed of smectic type liquid crystals.

Examine the phase diagram for the substance Bogusium (Bo) and select the correct statement.

The phase diagram for xenon has a solid-liquid curve with a positive slope. Which of the following is true?

Hexagonal close packing of identical atoms occurs when close-packed layers are stacked in an abcabc... arrangement.

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

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

Select the pair of substances in which the one with the higher vapor pressure at a given temperature is listed first.

A liquid may be made to boil at room temperature, simply by lowering the pressure.

Ceramic superconductors often contain copper in unusual oxidation states.

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?

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

Lead crystallizes in the face-centered cubic lattice. What is the coordination number for Pb?

Which of the following statements about ceramics is incorrect?

In which of the following compounds will the molecules not form hydrogen bonds with each other?

A metal with a body-centered cubic lattice will have __________ atom(s) per unit cell.

Which of the following statements concerning a face-centered cubic unit cell and the corresponding lattice, made up of identical atoms, is incorrect?

Keys to the Study of Chemistry: Definitions, Units, and Problem Solving

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 Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

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 Reaction Direction

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

What types of forces exist between molecules of CO₂?