Question 1

Which compound cannot be liquefied by compression, at a temperature of 25.0°C?

Accepted Answer

A) C2H4, critical point: 9.9°C, 50.5 atm 
B) CH3Cl, critical point: 144.0°C, 66.0 atm 
C) C2H2, critical point: 35.5°C, 61.6 atm 
D) C2H6, critical point: 32.2°C, 48.2 atm 
E) SO2, critical point: 158.0°C, 78.0 atm 
A) C2H4, critical point: 9.9°C, 50.5 atm 
B) CH3Cl, critical point: 144.0°C, 66.0 atm 
C) C2H2, critical point: 35.5°C, 61.6 atm 
D) C2H6, critical point: 32.2°C, 48.2 atm 
E) SO2, critical point: 158.0°C, 78.0 atm

Question 2

Substances with higher vapor pressures at room temperature will have a ________ boiling point than substances with lower vapor pressures.

Accepted Answer

The answer of Substances with higher vapor pressures at room...

Question 3

Portions of how many different atoms are in one simple cubic unit cell?

Accepted Answer

A) 2 
B) 3 
C) 4 
D) 6 
E) 8 
A) 2 
B) 3 
C) 4 
D) 6 
E) 8

Question 4

The following questions refer to the diagram below.  
-Does the curvature of the lines on this phase diagram look similar to those on the phase diagram of water? Why or why not?

Accepted Answer

The lines are not similar to the phase d

Question 5

Viscosity is determined only by the intermolecular attractive forces in a liquid.

Accepted Answer

A) True 
 B)False

Question 6

Supercooling is defined as

Accepted Answer

A) the extremely rapid cooling of a vapor to form a liquid. 
B) the use of extremely cold refrigerants to achieve smaller crystal size when liquids are frozen. 
C) the extremely rapid cooling of a liquid to form a softer crystalline solid. 
D) the cooling of a liquid to a temperature below its melting point without solidification. 
E) the cooling of a substance to absolute zero. 
A) the extremely rapid cooling of a vapor to form a liquid. 
B) the use of extremely cold refrigerants to achieve smaller crystal size when liquids are frozen. 
C) the extremely rapid cooling of a liquid to form a softer crystalline solid. 
D) the cooling of a liquid to a temperature below its melting point without solidification. 
E) the cooling of a substance to absolute zero.

Question 7

Benzene, C6H8, has an enthalpy of fusion of 127.4 J g-1 and its melting point temperature is 5.53°C. How much heat is required to transform 80.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?

Accepted Answer

A) 705 J 
B) 10.2 kJ 
C) 14.4 kJ 
D) 19.3 kJ 
E) 22.3 kJ 
A) 705 J 
B) 10.2 kJ 
C) 14.4 kJ 
D) 19.3 kJ 
E) 22.3 kJ

Question 8

The following questions refer to the basic phase diagram below with gas, liquid, and solid phases present and labeled.  
-If the substance starts at a pressure of 330 torr and -20°C and is heated at constant pressure to 20°C, what phase transition will occur?

Accepted Answer

The answer of The following questions refer to the basic...

Question 9

When a liquid undergoes a change of state to a gas, the process is called

Accepted Answer

A) condensation. 
B) deposition. 
C) fusion. 
D) sublimation. 
E) evaporation. 
A) condensation. 
B) deposition. 
C) fusion. 
D) sublimation. 
E) evaporation.

Question 10

What are the characteristics that distinguish solids, liquids, and gases? A complete answer will include a discussion of intermolecular forces and retention of shape and volume.

Accepted Answer

Gases have the weakest intermolecular fo

Question 11

When a gas undergoes a change of state to a liquid, the process is called

Accepted Answer

A) condensation. 
B) deposition. 
C) fusion. 
D) sublimation. 
E) evaporation. 
A) condensation. 
B) deposition. 
C) fusion. 
D) sublimation. 
E) evaporation.

Question 12

Explain how you could cause pure water to boil at a temperature of 25°C.

Accepted Answer

If it was possible to lower the external

Question 13

A solid with a molecular weight of 174.0 g/mol is at its melting point. If this solid requires 21.3 kJ of heat to melt 34.0 g, what is the molar heat of fusion of this solid (in kJ/mol)

Accepted Answer

A) 3.60 × 10-3 kJ/mol 
B) 4.16 kJ/mol 
C) 2.40 × 10-1 kJ/mol 
D) 109 kJ/mol 
E) 1.26 × 105 kJ/mol 
A) 3.60 × 10-3 kJ/mol 
B) 4.16 kJ/mol 
C) 2.40 × 10-1 kJ/mol 
D) 109 kJ/mol 
E) 1.26 × 105 kJ/mol

Question 14

Evaporation

Accepted Answer

A) is an endothermic process. 
B) is an exothermic process. 
C) involves breaking intermolecular forces. 
D) decreases the temperature on the surface where it occurs. 
E) A, C, and D 
A) is an endothermic process. 
B) is an exothermic process. 
C) involves breaking intermolecular forces. 
D) decreases the temperature on the surface where it occurs. 
E) A, C, and D

Question 15

Given this set of phase changes: condensation, freezing, fusion, sublimation, vaporization, which of these phase changes is/are exothermic?

Accepted Answer

Freezing a

Question 16

Paradichlorobenzene is a white crystalline solid which is very soft, has a low melting point, and does not conduct electricity. Which category of substance does it most likely fit under?

Accepted Answer

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

Question 17

The following questions refer to the phase diagram below.  
-What phase should this substance exist as, at a pressure of 2000 torr and a temperature of -70°C?

Accepted Answer

A) solid 
B) liquid 
C) gas 
D) supercritical fluid 
E) unable to tell 
A) solid 
B) liquid 
C) gas 
D) supercritical fluid 
E) unable to tell

Question 18

In a one-element solid with a face-centered cubic structure, how many atoms are in one unit cell?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) 4 
E) 5 
A) 1 
B) 2 
C) 3 
D) 4 
E) 5

Question 19

The following questions refer to the basic phase diagram below with gas, liquid, and solid phases present and labeled.  
-What phase of this substance exists at 2.15 torr and 80°C?

Accepted Answer

The answer of The following questions refer to the basic...

Question 20

Which of the following liquids, at the same temperature, has the highest vapor pressure?

Accepted Answer

A) CH3-Hg-CH3 
B) CH3-O-CH3 
C) CH3-S-CH3 
D) CH3-Se-CH3 
E) CH3-Te-CH3 
A) CH3-Hg-CH3 
B) CH3-O-CH3 
C) CH3-S-CH3 
D) CH3-Se-CH3 
E) CH3-Te-CH3

Exam 12: Intermolecular Attractions and the Properties of Liquids and Solids

Which compound cannot be liquefied by compression, at a temperature of 25.0°C?

Substances with higher vapor pressures at room temperature will have a ________ boiling point than substances with lower vapor pressures.

Portions of how many different atoms are in one simple cubic unit cell?

The following questions refer to the diagram below. -Does the curvature of the lines on this phase diagram look similar to those on the phase diagram of water? Why or why not?

Viscosity is determined only by the intermolecular attractive forces in a liquid.

Supercooling is defined as

Benzene, C6H8, has an enthalpy of fusion of 127.4 J g-1 and its melting point temperature is 5.53°C. How much heat is required to transform 80.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?

The following questions refer to the basic phase diagram below with gas, liquid, and solid phases present and labeled. -If the substance starts at a pressure of 330 torr and -20°C and is heated at constant pressure to 20°C, what phase transition will occur?

When a liquid undergoes a change of state to a gas, the process is called

What are the characteristics that distinguish solids, liquids, and gases? A complete answer will include a discussion of intermolecular forces and retention of shape and volume.

When a gas undergoes a change of state to a liquid, the process is called

Explain how you could cause pure water to boil at a temperature of 25°C.

A solid with a molecular weight of 174.0 g/mol is at its melting point. If this solid requires 21.3 kJ of heat to melt 34.0 g, what is the molar heat of fusion of this solid (in kJ/mol)

Evaporation

Given this set of phase changes: condensation, freezing, fusion, sublimation, vaporization, which of these phase changes is/are exothermic?

Paradichlorobenzene is a white crystalline solid which is very soft, has a low melting point, and does not conduct electricity. Which category of substance does it most likely fit under?

The following questions refer to the phase diagram below. -What phase should this substance exist as, at a pressure of 2000 torr and a temperature of -70°C?

In a one-element solid with a face-centered cubic structure, how many atoms are in one unit cell?

The following questions refer to the basic phase diagram below with gas, liquid, and solid phases present and labeled. -What phase of this substance exists at 2.15 torr and 80°C?

Which of the following liquids, at the same temperature, has the highest vapor pressure?

A Very Brief History of Chemistry

Scientific Measurements

Elements, Compounds, and the Periodic Table

The Mole and Stoichiometry

Molecular View of Reactions in Aqueous Solutions

Oxidation-Reduction Reactions

Energy and Chemical Change

The Quantum Mechanical Atom

The Basics of Chemical Bonding

Theories of Bonding and Structure

Properties of Gases

Mixtures at the Molecular Level: Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases, a Molecular Look

Acid-Base Equilibria in Aqueous Solutions

Solubility and Simultaneous Equilibria

Thermodynamics

Electrochemistry

Nuclear Reactions and Their Role in Chemistry

Metal Complexes

Organic Compounds, Polymers, and Biochemicals

Filters

Benzene, C₆H₈, has an enthalpy of fusion of 127.4 J g^-1 and its melting point temperature is 5.53°C. How much heat is required to transform 80.0 g of solid benzene at 5.53°C into liquid benzene, also at 5.53°C?