Question 1

Based on the phase diagram shown below, how will the melting point of the substance change if the pressure is increased above 1 atm?

Accepted Answer

A) The melting point will decrease. 
B) The melting point will remain the same. 
C) The melting point will increase. 
D) The substance will not melt at pressures of 1 atm and above; instead, the solid sublimes to form the gas phase. 
A) The melting point will decrease. 
B) The melting point will remain the same. 
C) The melting point will increase. 
D) The substance will not melt at pressures of 1 atm and above; instead, the solid sublimes to form the gas phase.

Question 2

Find the temperature at which water boils on a day in the mountains when the barometric pressure is 593 mmHg.(Given: the heat of vaporization of water is 40.79 kJ/mol)

Accepted Answer

A) 41.5°C 
B) 68.1°C 
C) 93.1°C 
D) 97.0°C 
E) 117°C 
A) 41.5°C 
B) 68.1°C 
C) 93.1°C 
D) 97.0°C 
E) 117°C

Question 3

Iron crystallizes in a body-centered cubic unit.The edge of this cell is 287 pm.Calculate the density of iron.

Accepted Answer

The answer of Iron crystallizes in a body-centered cubic unit.The...

Question 4

Osmium tetroxide, OsO4, is a soft crystal that melts at 40°C.The liquid does not conduct electricity.What kind of crystal is this?

Accepted Answer

Question 5

Crystals of elemental sulfur are easily crushed, and melt at 113°C.Liquid sulfur does not conduct electricity.What kind of crystal is this?

Accepted Answer

The answer of Crystals of elemental sulfur are easily crushed,...

Question 6

The triple point of iodine is at 0.12 atm and 115°C.Thus, liquid I2

Accepted Answer

A) is more dense than I2 (s). 
B) cannot exist above 115°C. 
C) is liquid at room temperature. 
D) cannot have a vapor pressure less than 91 torr. 
A) is more dense than I2 (s). 
B) cannot exist above 115°C. 
C) is liquid at room temperature. 
D) cannot have a vapor pressure less than 91 torr.

Question 7

The number of atoms in a face-centered cubic unit cell is

Accepted Answer

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

Question 8

Which of the following phase changes is endothermic?

Accepted Answer

A) Sublimation 
B) Condensation 
C) Freezing 
D) Deposition 
A) Sublimation 
B) Condensation 
C) Freezing 
D) Deposition

Question 9

The molar enthalpy of vaporization of hexane (C6H14)is 28.9 kJ/mol, and its normal boiling point is 68.73°C.What is the vapor pressure of hexane at 25°C?

Accepted Answer

A) 4.44 torr 
B) 117 torr 
C) 171 torr 
D) 759 torr 
E) 3370 torr 
A) 4.44 torr 
B) 117 torr 
C) 171 torr 
D) 759 torr 
E) 3370 torr

Question 10

Suppose the atoms in a two-dimensional crystal have the following arrangement:   On the drawing above, sketch the unit cell of this crystal.

Accepted Answer

The answer of Suppose the atoms in a two-dimensional crystal...

Question 11

Calculate the amount of enthalpy required to heat 25.0 g of solid benzene (C6H6)at -10°C to liquid benzene at 20.0°C.Thermodynamic data for benzene: specific heat of solid benzene = 1.52 J/g·°C; specific heat of liquid benzene = 1.73 J/g·°C; melting point = 5.5°C; $\Delta$Hfus = 9.9 kJ/mol.

Accepted Answer

Question 12

The intermolecular forces present in HSCH2CH2SH include which of the following? I.dipole-dipole
II.ion-dipole
III.dispersion
IV.hydrogen bonding

Accepted Answer

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

Question 13

A face-centered cubic unit cell is the repeating unit in which type of crystal packing?

Accepted Answer

A) hexagonal close-packed 
B) cubic close-packed 
C) body centered 
D) simple 
E) all of the above 
A) hexagonal close-packed 
B) cubic close-packed 
C) body centered 
D) simple 
E) all of the above

Question 14

Magnesium oxide, MgO, melts at 2,800°C and is very hard.The liquid conducts electricity very well.What kind of crystal is this?

Accepted Answer

The answer of Magnesium oxide, MgO, melts at 2,800°C and...

Question 15

Which property of water allows a razor blade to float on it without sinking?

Accepted Answer

A) viscosity 
B) surface tension 
C) density 
D) specific heat 
E) triple point 
A) viscosity 
B) surface tension 
C) density 
D) specific heat 
E) triple point

Question 16

The intermolecular forces present in CH3NH2 include which of the following? I.dipole-dipole
II.ion-dipole
III.dispersion
IV.hydrogen bonding

Accepted Answer

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

Question 17

A liquid boils when its

Accepted Answer

A) vapor pressure is exactly 1 atmosphere. 
B) vapor pressure is equal to, or greater than, the external pressure pushing on it. 
C) temperature is equal to 273 K (standard temperature). 
D) temperature is greater than room temperature. 
A) vapor pressure is exactly 1 atmosphere. 
B) vapor pressure is equal to, or greater than, the external pressure pushing on it. 
C) temperature is equal to 273 K (standard temperature). 
D) temperature is greater than room temperature.

Question 18

Which would have the higher boiling point CH3Cl or CH4?

Accepted Answer

Question 19

The zincblende structure of ZnS has the relatively large sulfide ions arranged at the lattice points of a face-centered cubic structure.The edge length of this cubic unit cell is 540.9 pm.Determine the density of zincblende.

Accepted Answer

A) 1.023 g/cm3 
B) 2.032 g/cm3 
C) 2.046 g/cm3 
D) 3.081 g/cm3 
E) 4.091 g/cm3 
A) 1.023 g/cm3 
B) 2.032 g/cm3 
C) 2.046 g/cm3 
D) 3.081 g/cm3 
E) 4.091 g/cm3

Question 20

Use the graph of vapor pressure to determine the normal boiling point of CHCl3.

Accepted Answer

A) 19°C 
B) 52°C 
C) 60°C 
D) 64°C 
E) 70°C 
A) 19°C 
B) 52°C 
C) 60°C 
D) 64°C 
E) 70°C

Exam 11: Intermolecular Forces and Liquids and Solids

Based on the phase diagram shown below, how will the melting point of the substance change if the pressure is increased above 1 atm?

Find the temperature at which water boils on a day in the mountains when the barometric pressure is 593 mmHg.(Given: the heat of vaporization of water is 40.79 kJ/mol)

Iron crystallizes in a body-centered cubic unit.The edge of this cell is 287 pm.Calculate the density of iron.

Osmium tetroxide, OsO4, is a soft crystal that melts at 40°C.The liquid does not conduct electricity.What kind of crystal is this?

Crystals of elemental sulfur are easily crushed, and melt at 113°C.Liquid sulfur does not conduct electricity.What kind of crystal is this?

The triple point of iodine is at 0.12 atm and 115°C.Thus, liquid I2

The number of atoms in a face-centered cubic unit cell is

Which of the following phase changes is endothermic?

The molar enthalpy of vaporization of hexane (C6H14)is 28.9 kJ/mol, and its normal boiling point is 68.73°C.What is the vapor pressure of hexane at 25°C?

Suppose the atoms in a two-dimensional crystal have the following arrangement: On the drawing above, sketch the unit cell of this crystal.

The intermolecular forces present in HSCH2CH2SH include which of the following? I.dipole-dipole II.ion-dipole III.dispersion IV.hydrogen bonding

A face-centered cubic unit cell is the repeating unit in which type of crystal packing?

Magnesium oxide, MgO, melts at 2,800°C and is very hard.The liquid conducts electricity very well.What kind of crystal is this?

Which property of water allows a razor blade to float on it without sinking?

The intermolecular forces present in CH3NH2 include which of the following? I.dipole-dipole II.ion-dipole III.dispersion IV.hydrogen bonding

A liquid boils when its

Which would have the higher boiling point CH3Cl or CH4?

The zincblende structure of ZnS has the relatively large sulfide ions arranged at the lattice points of a face-centered cubic structure.The edge length of this cubic unit cell is 540.9 pm.Determine the density of zincblende.

Use the graph of vapor pressure to determine the normal boiling point of CHCl3.

Chemistry: the Study of Change

Atoms, Molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solutions

Gases

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy Free Energy and Equilibrium

Electrochemistry

Nuclear Chemistry

Chemistry in the Atmosphere

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

Osmium tetroxide, OsO₄, is a soft crystal that melts at 40°C.The liquid does not conduct electricity.What kind of crystal is this?

The triple point of iodine is at 0.12 atm and 115°C.Thus, liquid I₂

The molar enthalpy of vaporization of hexane (C₆H₁₄)is 28.9 kJ/mol, and its normal boiling point is 68.73°C.What is the vapor pressure of hexane at 25°C?

The intermolecular forces present in HSCH₂CH₂SH include which of the following? I.dipole-dipole II.ion-dipole III.dispersion IV.hydrogen bonding

The intermolecular forces present in CH₃NH₂ include which of the following? I.dipole-dipole II.ion-dipole III.dispersion IV.hydrogen bonding

Which would have the higher boiling point CH₃Cl or CH₄?

Use the graph of vapor pressure to determine the normal boiling point of CHCl₃.