Question 1

Examine the following phase diagram and determine what phase exists at point F.

Accepted Answer

A) Vapor + Liquid 
B) Vapor 
C) Liquid 
D) Solid 
E) Supercritical fluid 
A) Vapor + Liquid 
B) Vapor 
C) Liquid 
D) Solid 
E) Supercritical fluid

Question 2

If the solid form of a pure substance is denser than its liquid form, an increase in pressure will cause the melting point to decrease.

Accepted Answer

A) True 
 B)False

Question 3

The energy of a hydrogen bond is greater than that of a typical covalent bond.

Accepted Answer

A) True 
 B)False

Question 4

Polonium crystallizes in the simple cubic lattice. What is the coordination number for Po?

Accepted Answer

A) 3 
B) 4 
C) 6 
D) 8 
E) 12 
A) 3 
B) 4 
C) 6 
D) 8 
E) 12

Question 5

When identical particles pack in a simple cubic lattice, there is/are __________ particle(s) per unit cell.

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 8 
A) 1 
B) 2 
C) 3 
D) 4 
E) 8

Question 6

All gases can be liquefied at room temperature simply by increasing the pressure on the gas.

Accepted Answer

A) True 
 B)False

Question 7

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. Calculate its heat of vaporization.

Accepted Answer

A) 43.4 kJ/mol 
B) 52.5 kJ/mol 
C) 70.6 kJ/mol 
D) 1.00 × 10 2 kJ/mol 
E) None of these choices are correct. 
A) 43.4 kJ/mol 
B) 52.5 kJ/mol 
C) 70.6 kJ/mol 
D) 1.00 × 10 2 kJ/mol 
E) None of these choices are correct.

Question 8

Liquid ammonia (boiling point = −33.4°C) can be used as a refrigerant and heat transfer fluid. How much energy is needed to heat 25.0 g of NH3(l) from −65.0°C to −12.0°C?

Accepted Answer

A) 5.5 kJ 
B) 6.3 kJ 
C) 39 kJ 
D) 340 kJ 
E) 590 kJ 
A) 5.5 kJ 
B) 6.3 kJ 
C) 39 kJ 
D) 340 kJ 
E) 590 kJ

Question 9

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 10

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 11

The normal boiling point of ether is 307.8 K. Calculate the temperature at which its vapor pressure is exactly half of that at its normal boiling point. The heat of vaporization for ether is 26.69 kJ/mol.

Accepted Answer

A) 305 K 
B) 302 K 
C) 295 K 
D) 289 K 
E) 281 K 
A) 305 K 
B) 302 K 
C) 295 K 
D) 289 K 
E) 281 K

Question 12

Which of the following should have the highest boiling point?

Accepted Answer

A) CF 4 
B) CCl 4 
C) CBr 4 
D) CI 4 
E) CH 4 
A) CF 4 
B) CCl 4 
C) CBr 4 
D) CI 4 
E) CH 4

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

Ammonia's unusually high melting point is the result of

Accepted Answer

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

Question 15

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

Accepted Answer

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

Question 16

What adjective best describes the solid compound IF7?

Accepted Answer

A) metallic 
B) amorphous 
C) covalent network 
D) molecular 
E) ionic 
A) metallic 
B) amorphous 
C) covalent network 
D) molecular 
E) ionic

Question 17

When liquid bromine is cooled to form a solid, which of the following types of solid would it form?

Accepted Answer

A) atomic 
B) metallic 
C) molecular 
D) ionic 
E) covalent network 
A) atomic 
B) metallic 
C) molecular 
D) ionic 
E) covalent network

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

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

Accepted Answer

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

Question 20

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.

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

Examine the following phase diagram and determine what phase exists at point F.

If the solid form of a pure substance is denser than its liquid form, an increase in pressure will cause the melting point to decrease.

The energy of a hydrogen bond is greater than that of a typical covalent bond.

Polonium crystallizes in the simple cubic lattice. What is the coordination number for Po?

When identical particles pack in a simple cubic lattice, there is/are __________ particle(s) per unit cell.

All gases can be liquefied at room temperature simply by increasing the pressure on the gas.

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. Calculate its heat of vaporization.

Liquid ammonia (boiling point = −33.4°C) can be used as a refrigerant and heat transfer fluid. How much energy is needed to heat 25.0 g of NH3(l) from −65.0°C to −12.0°C?

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

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

The normal boiling point of ether is 307.8 K. Calculate the temperature at which its vapor pressure is exactly half of that at its normal boiling point. The heat of vaporization for ether is 26.69 kJ/mol.

Which of the following should have the highest boiling point?

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

Ammonia's unusually high melting point is the result of

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

What adjective best describes the solid compound IF7?

When liquid bromine is cooled to form a solid, which of the following types of solid would it form?

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

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

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

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

Liquid ammonia (boiling point = −33.4°C) can be used as a refrigerant and heat transfer fluid. How much energy is needed to heat 25.0 g of NH₃(l) from −65.0°C to −12.0°C?

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

What adjective best describes the solid compound IF₇?

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