Question 1

Consider a lake that is uniformly 10°C. What happens to the oxygen-rich surface water as it cools down to   ?

Accepted Answer

A)  The oxygen gets squeezed out as the microcrystals form. 
B)  Its rate of evaporation decreases which has the effect of increasing the oxygen concentration. 
C)  It grows less dense and remains at the surface. 
D)  It grows more dense and sinks towards the bottom. 
A)  The oxygen gets squeezed out as the microcrystals form. 
B)  Its rate of evaporation decreases which has the effect of increasing the oxygen concentration. 
C)  It grows less dense and remains at the surface. 
D)  It grows more dense and sinks towards the bottom. D

Question 2

Heat is given off by a substance when that substance ________.

Accepted Answer

A)  evaporates 
B)  freezes 
C)  melts 
D)  boils 
E)  C and D 
A)  evaporates 
B)  freezes 
C)  melts 
D)  boils 
E)  C and D B

Question 3

Like water, hydrogen fluoride, HF, and ammonia, N   , have relatively high boiling points. Explain.

Accepted Answer

A)  Even though HF and N   have ionic bonds, like water they have a strong attraction for themselves. 
B)  Since these are all relatively small molecules, they can compact more tightly together, and will require more energy to be separated from each other. 
C)  The polar molecules of each of these materials have relatively strong attractions for themselves, which translates to relatively high boiling points. 
D)  Since these molecules interact with each other in long chains, they have many regions of attraction and are held together relatively tightly, thus, they are harder to pull apart when boiling. 
A)  Even though HF and N   have ionic bonds, like water they have a strong attraction for themselves. 
B)  Since these are all relatively small molecules, they can compact more tightly together, and will require more energy to be separated from each other. 
C)  The polar molecules of each of these materials have relatively strong attractions for themselves, which translates to relatively high boiling points. 
D)  Since these molecules interact with each other in long chains, they have many regions of attraction and are held together relatively tightly, thus, they are harder to pull apart when boiling. C

Question 4

What is the boiling temperature of a single water molecule? Does this question make sense?

Accepted Answer

A)  Boiling involves the separation of many molecules (plural). With only one molecule, the concept of boiling is meaningless. 
B)  Yes, this question does make sense because temperature measures the average kinetic energy of a molecule, which is 100°C for water. 
C)  100°C indicates when the covalent bonds of the water molecule has been broken to give rise to hydrogen and oxygen atoms which are released into atmosphere. 
D)  No, this question does not make sense because you need at least two molecules to get the average kinetic energy. 
A)  Boiling involves the separation of many molecules (plural). With only one molecule, the concept of boiling is meaningless. 
B)  Yes, this question does make sense because temperature measures the average kinetic energy of a molecule, which is 100°C for water. 
C)  100°C indicates when the covalent bonds of the water molecule has been broken to give rise to hydrogen and oxygen atoms which are released into atmosphere. 
D)  No, this question does not make sense because you need at least two molecules to get the average kinetic energy.

Question 5

From the diagram above describing the phase of water relative to temperature and pressure, at which point is water boiling?

Accepted Answer

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

Question 6

If the specific heat of aluminum is 0.90 J/(g°C), how much heat is needed to raise the temperature of a 10.0-gram piece of aluminum from 21°C to 61°C?

Accepted Answer

A)  360 J 
B)  180 J 
C)  540 J 
D)  900 J 
E)  90 J 
A)  360 J 
B)  180 J 
C)  540 J 
D)  900 J 
E)  90 J

Question 7

Why is calcium chloride,   , more effective at melting ice than sodium chloride, NaCl?

Accepted Answer

A)  Calcium ions are both larger and more highly charged and thus more effective in breaking the ice crystal structure. 
B)  Calcium ions are smaller than sodium ions and thus more able to get in the way of the water molecules attempting to form the solid state lattice. 
C)  Calcium chloride produces three ion particles while sodium chloride produces only two. Greater numbers of ions are more effective at decreasing the number of water molecules entering the solid phase. 
D)  Sodium ion is a natural water softener and therefore not as effective in inhibiting the formation of the solid state of water from the liquid. 
A)  Calcium ions are both larger and more highly charged and thus more effective in breaking the ice crystal structure. 
B)  Calcium ions are smaller than sodium ions and thus more able to get in the way of the water molecules attempting to form the solid state lattice. 
C)  Calcium chloride produces three ion particles while sodium chloride produces only two. Greater numbers of ions are more effective at decreasing the number of water molecules entering the solid phase. 
D)  Sodium ion is a natural water softener and therefore not as effective in inhibiting the formation of the solid state of water from the liquid.

Question 8

Why do ice cubes get smaller when left in the freezer for a long time?

Accepted Answer

A)  The ice cubes melt during the brief warming cycles of auto-defrost and freezer access, thus leaving the ice cubes smaller and making them stick together in clumps. 
B)  The water molecules of the ice sublime from the solid to gaseous phase without ever entering a liquid phase. 
C)  Both A and B occur. 
D)  Neither A nor B accurately explain why ice cubes get smaller in the freezer over time. 
A)  The ice cubes melt during the brief warming cycles of auto-defrost and freezer access, thus leaving the ice cubes smaller and making them stick together in clumps. 
B)  The water molecules of the ice sublime from the solid to gaseous phase without ever entering a liquid phase. 
C)  Both A and B occur. 
D)  Neither A nor B accurately explain why ice cubes get smaller in the freezer over time.

Question 9

What would happen to the oceans if the atmosphere suddenly disappeared?

Accepted Answer

A)  There would be little or no change. Oceans are known to exist on other planets without atmospheres. 
B)  The oceans would completely evaporate filling the void left by the atmosphere with water vapor and leaving behind billions of tons of salt deposit. 
C)  The missing air would be replaced by water vapor as the upper layers of the ocean began to boil. 
D)  The oceans would freeze to a solid ice mass since the temperature of the earth would drop below   . 
A)  There would be little or no change. Oceans are known to exist on other planets without atmospheres. 
B)  The oceans would completely evaporate filling the void left by the atmosphere with water vapor and leaving behind billions of tons of salt deposit. 
C)  The missing air would be replaced by water vapor as the upper layers of the ocean began to boil. 
D)  The oceans would freeze to a solid ice mass since the temperature of the earth would drop below   .

Question 10

Water coming out of volcanic sea vents at the bottom of the ocean can reach temperatures in excess of 300°C without boiling. How is this possible?

Accepted Answer

A)  The heat is immediately transferred to the surrounding, very cold water. 
B)  The heat is immediately transferred to the surrounding volcanic rock. 
C)  The water and water vapor reach equilibrium under the extreme pressure of the ocean. 
D)  The extreme pressure exerted by the miles of ocean water above prevent the formation of any bubbles of water vapor. 
A)  The heat is immediately transferred to the surrounding, very cold water. 
B)  The heat is immediately transferred to the surrounding volcanic rock. 
C)  The water and water vapor reach equilibrium under the extreme pressure of the ocean. 
D)  The extreme pressure exerted by the miles of ocean water above prevent the formation of any bubbles of water vapor.

Question 11

If it takes 200 J to raise the temperature of a 10-gram block of ice by 10°C, what is the specific heat of the ice?

Accepted Answer

A)  2 J/(g°
C)  
B)  200 J/(g°
C)  
C)  200 J 
D)  10 °C 
E)  20,000 J/(g°
C)  
A)  2 J/(g°
C)  
B)  200 J/(g°
C)  
C)  200 J 
D)  10 °C 
E)  20,000 J/(g°
C)

Question 12

Which of the above liquids would most likely have the least capillary action?

Accepted Answer

A)  a 
B)  b 
C)  c 
D)  d 
E)  e 
A)  a 
B)  b 
C)  c 
D)  d 
E)  e

Question 13

Is the food compartment in a refrigerator cooled by evaporation or condensation of the refrigerating coolant?

Accepted Answer

A)  The food compartment of a refrigerator is cooled by evaporation of the refrigerating fluid because vaporization is a cooling process. 
B)  The food compartment of a refrigerator is cooled by condensation of the refrigerating fluid because condensation is a cooling process. 
C)  Both evaporation and condensation of the refrigerating coolant cause the food compartment to cool. 
D)  It is neither the evaporation nor condensation of the refrigerating coolant that causes the food compartment to cool. Cooling is a matter of simple heat exchange via the refrigerator's motor. 
A)  The food compartment of a refrigerator is cooled by evaporation of the refrigerating fluid because vaporization is a cooling process. 
B)  The food compartment of a refrigerator is cooled by condensation of the refrigerating fluid because condensation is a cooling process. 
C)  Both evaporation and condensation of the refrigerating coolant cause the food compartment to cool. 
D)  It is neither the evaporation nor condensation of the refrigerating coolant that causes the food compartment to cool. Cooling is a matter of simple heat exchange via the refrigerator's motor.

Question 14

Will wrapping a bottle in a wet cloth produce a cooler bottle than placing the bottle in a bucket of cold water?

Accepted Answer

A)  The cloth of cold water will cool the bottled water down through the transfer of thermal energy to the cloth, and then insulate it from being warmed by the surrounding air. 
B)  A bottle in a bucket of water will be cooler since the thermal energy is transferred to billions of water molecules in the bucket of water. 
C)  A bottle wrapped in wet cloth will cool by the evaporation of liquid from the cloth. As evaporation progresses, the average temperature of the liquid left behind in the cloth can easily drop below the temperature of the cool water that wet it in the first place. 
D)  The cloth can cool the bottle of water down, but only until it reaches the temperature a few degrees below the surrounding atmosphere. After that, evaporation and condensation will reach equilibrium between the cloth and air. 
A)  The cloth of cold water will cool the bottled water down through the transfer of thermal energy to the cloth, and then insulate it from being warmed by the surrounding air. 
B)  A bottle in a bucket of water will be cooler since the thermal energy is transferred to billions of water molecules in the bucket of water. 
C)  A bottle wrapped in wet cloth will cool by the evaporation of liquid from the cloth. As evaporation progresses, the average temperature of the liquid left behind in the cloth can easily drop below the temperature of the cool water that wet it in the first place. 
D)  The cloth can cool the bottle of water down, but only until it reaches the temperature a few degrees below the surrounding atmosphere. After that, evaporation and condensation will reach equilibrium between the cloth and air.

Question 15

What happens to the temperature of something while it is boiling?

Accepted Answer

A)  temperature stays the same 
B)  temperature drops 
C)  temperature increases 
D)  Boiling is a cooling process, so temperature should decrease. 
E)  Boiling requires energy, so the temperature should go up. 
A)  temperature stays the same 
B)  temperature drops 
C)  temperature increases 
D)  Boiling is a cooling process, so temperature should decrease. 
E)  Boiling requires energy, so the temperature should go up.

Question 16

Where is the boiling point of water the greatest: at the bottom of a pot of water or just below the surface?

Accepted Answer

A)  The boiling point of water is the same throughout the pot. 
B)  The boiling point of water is is the greatest at the bottom where the density is greatest. 
C)  The boiling point of water is greatest where the water pressure is least, which is just below the surface. 
D)  The boiling point of water is greatest where the water pressure is greatest, which is at the bottom. 
A)  The boiling point of water is the same throughout the pot. 
B)  The boiling point of water is is the greatest at the bottom where the density is greatest. 
C)  The boiling point of water is greatest where the water pressure is least, which is just below the surface. 
D)  The boiling point of water is greatest where the water pressure is greatest, which is at the bottom.

Question 17

Dip a paper clip into water and then slowly pull it out. You'll find that for a short distance, the water is brought up with the metal. Are these adhesive or cohesive forces at work?

Accepted Answer

A)  These are the adhesive forces between the water and the metal (two different materials). The type of molecular interactions going on are dipole-induced dipole. 
B)  These are the adhesive forces between the water molecules. The type of molecular interactions going on are dipole-induced dipole. 
C)  These are the adhesive forces between the water and the metal (two different materials). The type of molecular interactions going on are dipole-dipole. 
D)  These are the cohesive forces between the water molecules. Water has such a strong attraction for itself that it will cling to the water on the paper clip until the force of gravity is stronger than its cohesive forces. 
A)  These are the adhesive forces between the water and the metal (two different materials). The type of molecular interactions going on are dipole-induced dipole. 
B)  These are the adhesive forces between the water molecules. The type of molecular interactions going on are dipole-induced dipole. 
C)  These are the adhesive forces between the water and the metal (two different materials). The type of molecular interactions going on are dipole-dipole. 
D)  These are the cohesive forces between the water molecules. Water has such a strong attraction for itself that it will cling to the water on the paper clip until the force of gravity is stronger than its cohesive forces.

Question 18

Why does a paper clip float when placed on water?

Accepted Answer

A)  It is lighter than water. 
B)  It is less dense than water. 
C)  It only floats on dense, cold water. 
D)  The molecules of water hold together and keep it from sinking. 
A)  It is lighter than water. 
B)  It is less dense than water. 
C)  It only floats on dense, cold water. 
D)  The molecules of water hold together and keep it from sinking.

Question 19

Why are drops of water shaped like spheres?

Accepted Answer

A)  Water molecules at the surface are pulled into the liquid, making the drop as small as possible. 
B)  The interatomic forces are strongest for spherical shapes and so the molecules arrange into spheres. 
C)  Water molecules are composed of spheres and so the bulk material takes on the same shape. 
D)  Water molecules are special and are the only molecules that form spheres. This is one of water's unique physical properties. 
A)  Water molecules at the surface are pulled into the liquid, making the drop as small as possible. 
B)  The interatomic forces are strongest for spherical shapes and so the molecules arrange into spheres. 
C)  Water molecules are composed of spheres and so the bulk material takes on the same shape. 
D)  Water molecules are special and are the only molecules that form spheres. This is one of water's unique physical properties.

Question 20

Why does water expand when it goes from a liquid to a solid?

Accepted Answer

A)  The water molecules become aligned in a way that creates extra volume. 
B)  The liquid has a higher density than the ice. 
C)  Ice molecules are bigger than water molecules. 
D)  The liquid water molecules are bigger and shrink when cooled. 
E)  none of the above 
A)  The water molecules become aligned in a way that creates extra volume. 
B)  The liquid has a higher density than the ice. 
C)  Ice molecules are bigger than water molecules. 
D)  The liquid water molecules are bigger and shrink when cooled. 
E)  none of the above

Consider a lake that is uniformly 10°C. What happens to the oxygen-rich surface water as it cools down to ?

Heat is given off by a substance when that substance ________.

Like water, hydrogen fluoride, HF, and ammonia, N , have relatively high boiling points. Explain.

What is the boiling temperature of a single water molecule? Does this question make sense?

From the diagram above describing the phase of water relative to temperature and pressure, at which point is water boiling?

If the specific heat of aluminum is 0.90 J/(g°C), how much heat is needed to raise the temperature of a 10.0-gram piece of aluminum from 21°C to 61°C?

Why is calcium chloride, , more effective at melting ice than sodium chloride, NaCl?

Why do ice cubes get smaller when left in the freezer for a long time?

What would happen to the oceans if the atmosphere suddenly disappeared?

Water coming out of volcanic sea vents at the bottom of the ocean can reach temperatures in excess of 300°C without boiling. How is this possible?

If it takes 200 J to raise the temperature of a 10-gram block of ice by 10°C, what is the specific heat of the ice?

Which of the above liquids would most likely have the least capillary action?

Is the food compartment in a refrigerator cooled by evaporation or condensation of the refrigerating coolant?

Will wrapping a bottle in a wet cloth produce a cooler bottle than placing the bottle in a bucket of cold water?

What happens to the temperature of something while it is boiling?

Where is the boiling point of water the greatest: at the bottom of a pot of water or just below the surface?

Dip a paper clip into water and then slowly pull it out. You'll find that for a short distance, the water is brought up with the metal. Are these adhesive or cohesive forces at work?

Why does a paper clip float when placed on water?

Why are drops of water shaped like spheres?

Why does water expand when it goes from a liquid to a solid?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Chemicals React

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

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Exam 8: How Water Behaves

Consider a lake that is uniformly 10°C. What happens to the oxygen-rich surface water as it cools down to ?

Heat is given off by a substance when that substance ________.

Like water, hydrogen fluoride, HF, and ammonia, N , have relatively high boiling points. Explain.

What is the boiling temperature of a single water molecule? Does this question make sense?

From the diagram above describing the phase of water relative to temperature and pressure, at which point is water boiling?

If the specific heat of aluminum is 0.90 J/(g°C), how much heat is needed to raise the temperature of a 10.0-gram piece of aluminum from 21°C to 61°C?

Why is calcium chloride, , more effective at melting ice than sodium chloride, NaCl?

Why do ice cubes get smaller when left in the freezer for a long time?

What would happen to the oceans if the atmosphere suddenly disappeared?

Water coming out of volcanic sea vents at the bottom of the ocean can reach temperatures in excess of 300°C without boiling. How is this possible?

If it takes 200 J to raise the temperature of a 10-gram block of ice by 10°C, what is the specific heat of the ice?

Which of the above liquids would most likely have the least capillary action?

Is the food compartment in a refrigerator cooled by evaporation or condensation of the refrigerating coolant?

Will wrapping a bottle in a wet cloth produce a cooler bottle than placing the bottle in a bucket of cold water?

What happens to the temperature of something while it is boiling?

Where is the boiling point of water the greatest: at the bottom of a pot of water or just below the surface?

Dip a paper clip into water and then slowly pull it out. You'll find that for a short distance, the water is brought up with the metal. Are these adhesive or cohesive forces at work?

Why does a paper clip float when placed on water?

Why are drops of water shaped like spheres?

Why does water expand when it goes from a liquid to a solid?

About Science

Particles of Matter

Elements of Chemistry

Subatomic Particles

The Atomic Nucleus

How Atoms Bond

How Molecules Mix

How Chemicals React

Acids and Bases in Our Environment

Oxidations and Reductions Charge the World

Organic Compounds

Nutrients of Life

Medicinal Chemistry

Optimizing Food Production

Protection Water and Air Resources

Capturing Energy

Filters