Question 1

Unlike fresh water, ocean water contracts as it is cooled all the way down to its freezing point, which is about -18°C. Why?

Accepted Answer

A) As the water cools, it becomes more dense and then it sinks. The pressure from the weight of the ocean exerted on the ice below the surface of water causes it to be more dense. 
B) macrocrystals instead of microcrystals are formed during the freezing of ocean water. 
C) As the water cools, the salt ions in the ocean water pull the molecules closer together. 
D) The presence of a solute disrupts the rate of ice microcrystal formation. 
A) As the water cools, it becomes more dense and then it sinks. The pressure from the weight of the ocean exerted on the ice below the surface of water causes it to be more dense. 
B) macrocrystals instead of microcrystals are formed during the freezing of ocean water. 
C) As the water cools, the salt ions in the ocean water pull the molecules closer together. 
D) The presence of a solute disrupts the rate of ice microcrystal formation.

Question 2

A walnut stuck to a pin is burned beneath a can containing 100.0 grams of water at 21°C. After the walnut has completely burned, the water's final temperature is a warmer 28°C. How much heat energy arose from the burning walnut?

Accepted Answer

A) 3,000 joules 
B) 9,000 joules 
C) 5,000 joules 
D) 2,000 joules 
A) 3,000 joules 
B) 9,000 joules 
C) 5,000 joules 
D) 2,000 joules

Question 3

Which of the above liquids has the strongest cohesive forces?

Accepted Answer

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

Question 4

What is found within the extra volume that arises as water expands upon freezing?

Accepted Answer

A) nothing 
B) other water molecules 
C) air 
D) dissolved oxygen 
E) the atoms have expanded 
A) nothing 
B) other water molecules 
C) air 
D) dissolved oxygen 
E) the atoms have expanded

Question 5

If you keep a mixture of water and ice at 0°C what will happen?

Accepted Answer

A) Nothing, the ice and water will stay the same. 
B) The water will freeze and become ice. 
C) The ice will melt and become water. 
D) The water will dissolve the ice. 
E) The ice will absorb the water. 
A) Nothing, the ice and water will stay the same. 
B) The water will freeze and become ice. 
C) The ice will melt and become water. 
D) The water will dissolve the ice. 
E) The ice will absorb the water.

Question 6

If the heat of melting of a sample is 135 J/g, what would the heat of freezing for the sample be?

Accepted Answer

A) -135 J/g 
B) 135 J/g 
C) The heat depends on the mass. 
D) The heat depends on the temperature. 
E) The heat of freezing is unrelated to the heat of melting. 
A) -135 J/g 
B) 135 J/g 
C) The heat depends on the mass. 
D) The heat depends on the temperature. 
E) The heat of freezing is unrelated to the heat of melting.

Question 7

Which statement best describes what is happening at the surface of liquid water?

Accepted Answer

A) At the surface there is a constant exchange of liquid and gaseous water. 
B) Fast moving water molecules leave the surface and become gas molecules. 
C) Slow moving gas molecules are captured by the liquid water. 
D) The gas molecules exchange with the liquid molecules. 
E) all of the above 
A) At the surface there is a constant exchange of liquid and gaseous water. 
B) Fast moving water molecules leave the surface and become gas molecules. 
C) Slow moving gas molecules are captured by the liquid water. 
D) The gas molecules exchange with the liquid molecules. 
E) all of the above

Question 8

If the specific heat of gold is 0.13 J/(g°C), how much heat is needed to raise the temperature of a 20-gram nugget by 20°C?

Accepted Answer

A) 50 J 
B) 500 J 
C) 5 J 
D) 20 J 
E) 0.13 J 
A) 50 J 
B) 500 J 
C) 5 J 
D) 20 J 
E) 0.13 J

Question 9

If you add heat energy to water molecules in the form of ice, where does the energy go?

Accepted Answer

A) The energy is used to break hydrogen bonds. 
B) Energy is neither created nor destroyed. 
C) The energy is used to make hydrogen bonds. 
D) Energy causes the molecules to arrange in regular arrays. 
E) none of the above 
A) The energy is used to break hydrogen bonds. 
B) Energy is neither created nor destroyed. 
C) The energy is used to make hydrogen bonds. 
D) Energy causes the molecules to arrange in regular arrays. 
E) none of the above

Question 10

From the diagram above describing the phase of water relative to temperature and pressure, at which point does water exist in all three phases?

Accepted Answer

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

Question 11

If the winds at the latitude of San Francisco and Washington, D.C., were from the east rather than from the west, why might San Francisco be able to grow cherry trees and Washington, D.C. palm trees?

Accepted Answer

A) The warm winds from Hawaii would stop blowing over San Francisco, giving it a cooler climate. The warm winds from Bermuda would warm up Washington, D.C. 
B) Cherries need a dryer climate, such as the winds from Nevada, and palm trees need moister air, which would come from the Atlantic ocean. 
C) The evaporation of water gives off heat, which would keep Washington, D.C. warm if the Atlantic winds blew eastward. This effect on the climate would be lost if the winds changed direction in San Francisco. 
D) As the ocean off the west coast cools in the winter, the heat it loses warms the air that blows over San Francisco warming its climate. If the winds were from the east, this same effect would keep Washington, D.C. warm with its surrounding ocean, and San Francisco would only have the cool winds of Nevada determining its temperatures. 
A) The warm winds from Hawaii would stop blowing over San Francisco, giving it a cooler climate. The warm winds from Bermuda would warm up Washington, D.C. 
B) Cherries need a dryer climate, such as the winds from Nevada, and palm trees need moister air, which would come from the Atlantic ocean. 
C) The evaporation of water gives off heat, which would keep Washington, D.C. warm if the Atlantic winds blew eastward. This effect on the climate would be lost if the winds changed direction in San Francisco. 
D) As the ocean off the west coast cools in the winter, the heat it loses warms the air that blows over San Francisco warming its climate. If the winds were from the east, this same effect would keep Washington, D.C. warm with its surrounding ocean, and San Francisco would only have the cool winds of Nevada determining its temperatures.

Question 12

If the specific heat of gold is 0.13 J/(g°C), how much heat does it take to raise the temperature of a 1.0-gram piece of gold from 74°C to 99°C?

Accepted Answer

A) 3.3 J 
B) 9.75 J 
C) 13.0 J 
D) 75,000 J 
E) 192 J 
A) 3.3 J 
B) 9.75 J 
C) 13.0 J 
D) 75,000 J 
E) 192 J

Question 13

Why does transforming water from 100°C liquid to 100°C gas require much more energy than to raise the temperature of the same amount of water from absolute zero all the way to 100°C liquid?

Accepted Answer

A) While water is in the solid phase, it is only necessary to impart energy to the water molecules themselves. Once in the liquid phase much more heat is required to impart sufficient energy to the molecules because there is more volume present. 
B) False! It does not require more energy to transform water from 100°C liquid to 100°C gas than to raise the temperature of the same amount of water from absolute zero all the way to 100°C liquid. 
C) Transforming water from 100°C liquid to 100°C gas requires breaking the hydrogen bonds between the liquid molecules. 
D) The amount of heat required to raise the temperature of the water or transform its phase is directly proportional to the densities of the water molecules involved. Obviously, driving liquid water to the vapor will drastically change its density. 
A) While water is in the solid phase, it is only necessary to impart energy to the water molecules themselves. Once in the liquid phase much more heat is required to impart sufficient energy to the molecules because there is more volume present. 
B) False! It does not require more energy to transform water from 100°C liquid to 100°C gas than to raise the temperature of the same amount of water from absolute zero all the way to 100°C liquid. 
C) Transforming water from 100°C liquid to 100°C gas requires breaking the hydrogen bonds between the liquid molecules. 
D) The amount of heat required to raise the temperature of the water or transform its phase is directly proportional to the densities of the water molecules involved. Obviously, driving liquid water to the vapor will drastically change its density.

Question 14

Which graph most appropriately shows the density of water plotted against temperature?

Accepted Answer

A) graph a 
B) graph b 
C) graph c 
D) graph d 
A) graph a 
B) graph b 
C) graph c 
D) graph d

Question 15

Water is most dense at ________.

Accepted Answer

A) -4°C 
B) 0°C 
C) +4°C 
D) +100°C 
A) -4°C 
B) 0°C 
C) +4°C 
D) +100°C

Question 16

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 17

If you were somehow able to sit at the surface of an ice cube and were able to slow the movement of water molecules from the solid to the liquid phase, what would eventually happen to the ice cube?

Accepted Answer

A) It would increase in size. 
B) It would melt because you are sitting on it and you give off heat. 
C) It would melt because you have slowed the rate of water uptake. 
D) It would melt because you have increased the rate of water uptake. 
E) none of the above 
A) It would increase in size. 
B) It would melt because you are sitting on it and you give off heat. 
C) It would melt because you have slowed the rate of water uptake. 
D) It would melt because you have increased the rate of water uptake. 
E) none of the above

Question 18

Antarctica, which is mostly ice, is much colder than the Arctic, which is a mixture of ice and water. Why?

Accepted Answer

A) The liquid water of the Arctic Ocean absorbs and releases a lot of heat that keeps the temperatures in that region from fluctuating. 
B) The Arctic is much farther north than the Antarctic. 
C) The salt in the water of the Antarctic keeps the water from freezing. 
D) The specific heat of the ice is less than that of liquid water, which allows its temperature to change more readily. 
E) Two of the above are reasonable. 
A) The liquid water of the Arctic Ocean absorbs and releases a lot of heat that keeps the temperatures in that region from fluctuating. 
B) The Arctic is much farther north than the Antarctic. 
C) The salt in the water of the Antarctic keeps the water from freezing. 
D) The specific heat of the ice is less than that of liquid water, which allows its temperature to change more readily. 
E) Two of the above are reasonable.

Question 19

A material with a high specific heat ________.

Accepted Answer

A) takes a lot of energy to change its temperature 
B) melts at a high temperature 
C) rapidly cools, giving up its heat 
D) changes temperature very rapidly when heated 
E) takes a very small temperature change to change the amount of heat in a material 
A) takes a lot of energy to change its temperature 
B) melts at a high temperature 
C) rapidly cools, giving up its heat 
D) changes temperature very rapidly when heated 
E) takes a very small temperature change to change the amount of heat in a material

Question 20

Why does a lake freeze from the top down?

Accepted Answer

A) As cold water cools towards freezing it gets less dense. 
B) The cold air is at the top of the lake. 
C) Cold water sinks, warm water rises. 
D) Warm water sinks, cold water rises. 
E) none of the above 
A) As cold water cools towards freezing it gets less dense. 
B) The cold air is at the top of the lake. 
C) Cold water sinks, warm water rises. 
D) Warm water sinks, cold water rises. 
E) none of the above

Unlike fresh water, ocean water contracts as it is cooled all the way down to its freezing point, which is about -18°C. Why?

A walnut stuck to a pin is burned beneath a can containing 100.0 grams of water at 21°C. After the walnut has completely burned, the water's final temperature is a warmer 28°C. How much heat energy arose from the burning walnut?

Which of the above liquids has the strongest cohesive forces?

What is found within the extra volume that arises as water expands upon freezing?

If you keep a mixture of water and ice at 0°C what will happen?

If the heat of melting of a sample is 135 J/g, what would the heat of freezing for the sample be?

Which statement best describes what is happening at the surface of liquid water?

If the specific heat of gold is 0.13 J/(g°C), how much heat is needed to raise the temperature of a 20-gram nugget by 20°C?

If you add heat energy to water molecules in the form of ice, where does the energy go?

From the diagram above describing the phase of water relative to temperature and pressure, at which point does water exist in all three phases?

If the winds at the latitude of San Francisco and Washington, D.C., were from the east rather than from the west, why might San Francisco be able to grow cherry trees and Washington, D.C. palm trees?

If the specific heat of gold is 0.13 J/(g°C), how much heat does it take to raise the temperature of a 1.0-gram piece of gold from 74°C to 99°C?

Why does transforming water from 100°C liquid to 100°C gas require much more energy than to raise the temperature of the same amount of water from absolute zero all the way to 100°C liquid?

Which graph most appropriately shows the density of water plotted against temperature?

Water is most dense at ________.

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

If you were somehow able to sit at the surface of an ice cube and were able to slow the movement of water molecules from the solid to the liquid phase, what would eventually happen to the ice cube?

Antarctica, which is mostly ice, is much colder than the Arctic, which is a mixture of ice and water. Why?

A material with a high specific heat ________.

Why does a lake freeze from the top down?

About Science

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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

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Exam 8: How Water Behaves

Unlike fresh water, ocean water contracts as it is cooled all the way down to its freezing point, which is about -18°C. Why?

A walnut stuck to a pin is burned beneath a can containing 100.0 grams of water at 21°C. After the walnut has completely burned, the water's final temperature is a warmer 28°C. How much heat energy arose from the burning walnut?

Which of the above liquids has the strongest cohesive forces?

What is found within the extra volume that arises as water expands upon freezing?

If you keep a mixture of water and ice at 0°C what will happen?

If the heat of melting of a sample is 135 J/g, what would the heat of freezing for the sample be?

Which statement best describes what is happening at the surface of liquid water?

If the specific heat of gold is 0.13 J/(g°C), how much heat is needed to raise the temperature of a 20-gram nugget by 20°C?

If you add heat energy to water molecules in the form of ice, where does the energy go?

From the diagram above describing the phase of water relative to temperature and pressure, at which point does water exist in all three phases?

If the winds at the latitude of San Francisco and Washington, D.C., were from the east rather than from the west, why might San Francisco be able to grow cherry trees and Washington, D.C. palm trees?

If the specific heat of gold is 0.13 J/(g°C), how much heat does it take to raise the temperature of a 1.0-gram piece of gold from 74°C to 99°C?

Why does transforming water from 100°C liquid to 100°C gas require much more energy than to raise the temperature of the same amount of water from absolute zero all the way to 100°C liquid?

Which graph most appropriately shows the density of water plotted against temperature?

Water is most dense at ________.

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

If you were somehow able to sit at the surface of an ice cube and were able to slow the movement of water molecules from the solid to the liquid phase, what would eventually happen to the ice cube?

Antarctica, which is mostly ice, is much colder than the Arctic, which is a mixture of ice and water. Why?

A material with a high specific heat ________.

Why does a lake freeze from the top down?

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