Question 1

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 2

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 3

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 4

The phase diagram of a substance can be used to obtain the vapor pressure of that substance at a given temperature.

Accepted Answer

A) True 
 B)False

Question 5

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

Accepted Answer

A) True 
 B)False

Question 6

The Clausius-Clapeyron equation is used in calculations of

Accepted Answer

A)  melting and freezing points. 
B)  vapor pressures of liquids. 
C)  osmotic pressures of solutions. 
D)  heats of vaporization at different temperatures. 
E)  crystal structure. 
A)  melting and freezing points. 
B)  vapor pressures of liquids. 
C)  osmotic pressures of solutions. 
D)  heats of vaporization at different temperatures. 
E)  crystal structure.

Question 7

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

Accepted Answer

A)  C7H16, C5H12 
B)  CCl4, CBr4 
C)  H2O, H2S 
D)  CH3CH2OH, CH3-O-CH3 
E)  Xe, Kr 
A)  C7H16, C5H12 
B)  CCl4, CBr4 
C)  H2O, H2S 
D)  CH3CH2OH, CH3-O-CH3 
E)  Xe, Kr

Question 8

a. Explain what is meant by the term "unit cell".
b. Copper metal has a face-centered cubic unit cell. The edge length of the unit cell is 361 pm, and the atomic weight of copper is 63.55 amu. Calculate the density of the copper in g/cm3.
(1 amu = 1.661 × 10-24 g.)
c. From the data in (b), calculate the radius of a copper atom in pm.

Accepted Answer

a. A unit cell is the smallest repeating

Question 9

Crystal structures may be conveniently measured using

Accepted Answer

A)  X-ray diffraction. 
B)  infrared spectroscopy. 
C)  ultraviolet-visible spectroscopy. 
D)  microwave spectroscopy. 
E)  magnetic resonance imaging. 
A)  X-ray diffraction. 
B)  infrared spectroscopy. 
C)  ultraviolet-visible spectroscopy. 
D)  microwave spectroscopy. 
E)  magnetic resonance imaging.

Question 10

Which of the following has a boiling point which does not fit the general trend?

Accepted Answer

A)  NH3 
B)  PH3 
C)  AsH3 
D)  SbH3 
E)  BiH3 
A)  NH3 
B)  PH3 
C)  AsH3 
D)  SbH3 
E)  BiH3

Question 11

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 12

Octane is a component of fuel used in internal combustion engines. The dominant intermolecular forces in octane are

Accepted Answer

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

Question 13

Strontium metal crystallizes in a cubic unit cell which has an edge length of 612 pm. If the mass of an atom of Sr is 87.62 amu, and the density of Sr metal is 2.54 g/cm3, calculate the number of atoms per unit cell. (1 amu = 1.661 × 10-24 g.)

Accepted Answer

Question 14

Assuming that atoms are spherical, calculate the fraction of space which is occupied by atoms (i.e., the packing efficiency) in a metal with a face-centered cubic unit cell.

Accepted Answer

The answer of Assuming that atoms are spherical, calculate the...

Question 15

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 16

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

Accepted Answer

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

Question 17

In cubic closest packing, the unit cell is body-centered cubic.

Accepted Answer

A) True 
 B)False

Question 18

In the packing of identical atoms with cubic unit cells, the packing efficiency increases as the coordination number increases.

Accepted Answer

A) True 
 B)False

Question 19

Germanium is a semiconductor. With the aid of diagrams showing bands of molecular orbital, explain why it is a poor conductor and how doping it with phosphorus increases its conductivity.

Accepted Answer

@#IMG-DLM& In pure Ge, very few electrons have suf

Question 20

The highest temperature at which superconductivity has been achieved is approximately

Accepted Answer

A)  4 K. 
B)  30 K. 
C)  70 K. 
D)  100 K. 
E)  130 K. 
A)  4 K. 
B)  30 K. 
C)  70 K. 
D)  100 K. 
E)  130 K.

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

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?

The phase diagram of a substance can be used to obtain the vapor pressure of that substance at a given temperature.

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

The Clausius-Clapeyron equation is used in calculations of

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

Crystal structures may be conveniently measured using

Which of the following has a boiling point which does not fit the general trend?

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

Octane is a component of fuel used in internal combustion engines. The dominant intermolecular forces in octane are

Strontium metal crystallizes in a cubic unit cell which has an edge length of 612 pm. If the mass of an atom of Sr is 87.62 amu, and the density of Sr metal is 2.54 g/cm3, calculate the number of atoms per unit cell. (1 amu = 1.661 × 10-24 g.)

Assuming that atoms are spherical, calculate the fraction of space which is occupied by atoms (i.e., the packing efficiency) in a metal with a face-centered cubic unit cell.

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

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

In cubic closest packing, the unit cell is body-centered cubic.

In the packing of identical atoms with cubic unit cells, the packing efficiency increases as the coordination number increases.

Germanium is a semiconductor. With the aid of diagrams showing bands of molecular orbital, explain why it is a poor conductor and how doping it with phosphorus increases its conductivity.

The highest temperature at which superconductivity has been achieved is approximately

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

The 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: Bonding, Structure, and Reactivity

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 Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

What adjective best describes the solid compound IF₇?

Strontium metal crystallizes in a cubic unit cell which has an edge length of 612 pm. If the mass of an atom of Sr is 87.62 amu, and the density of Sr metal is 2.54 g/cm³, calculate the number of atoms per unit cell. (1 amu = 1.661 × 10^-24 g.)