Deck 17: Change of Phase

Question 1

A hot dog pants

A)to enable evaporation in its mouth and bronchial tract.
B)to provide more oxygen into its lungs.
C)to impress dogs of the opposite sex.
D)none of the above

Answer 1

to enable evaporation in its mouth and bronchial tract.

Question 2

A boy scout will be burned more severely by

A)100 g of water at 100°C.
B)100 g of steam at 100°C.
C)both about equally
D)neither of these

Answer 2

100 g of steam at 100°C.

Question 3

What occurs in a pan of water placed outdoors on a warm day?

A)evaporation
B)condensation
C)both of these
D)neither of these

Answer 3

both of these

Question 4

The molecules in a room-temperature glass of water jostle around at

A)a great variety of speeds.
B)much the same rates of speed.
C)a very small range of speeds.

Question 5

The pressure at the bottom of a geyser is

A)less than nearer the top.
B)the same as nearer the top
C)greater than nearer the top.
D)all of the above
E)none of the above

Question 6

Double-pane windows contain nitrogen rather than air to prevent

A)gas escape.
B)thermal conduction.
C)condensation.
D)heat flow.

Question 7

The reason that evaporation is a cooling process is

A)radiation of heat during the process.
B)due to conduction and convection.
C)the more energetic molecules escape the liquid.
D)all of the above
E)none of the above

Question 8

Steam burns are more damaging than burns caused by boiling water because steam

A)has more energy per gram than boiling water.
B)releases additional energy when it condenses.
C)both of these
D)neither of these

Question 9

The main difference between a fog and a cloud is

A)water vapor content.
B)density of vapor.
C)seeding.
D)altitude.
E)temperature.

Question 10

On a muggy day, water molecules in the air that strike our bodies

A)transfer some of their kinetic energy to us.
B)gain kinetic energy as they change phase.
C)form an insulating layer on our bodies.

Question 11

Wrapping a hot potato in aluminum foil significantly reduces the rate at which it cools by

A)conduction.
B)condensation.
C)evaporation.
D)melting.

Question 12

When you blow over hot soup to cool it you are helping

A)to slightly increase air pressure atop the soup surface.
B)more energetic particles in the soup to escape.
C)conduction, convection, and radiation.
D)none of the above

Question 13

The surface of hot water has a relatively high rate of

A)evaporation.
B)condensation.
C)conductivity.
D)convection.

Question 14

We feel uncomfortably warm on a muggy day because water molecules are

A)evaporating from our moist bodies.
B)condensing on our bodies.
C)evaporating and condensing on our bodies at the same rate.
D)none of the above

Question 15

Evaporation is a cooling process and condensation is

A)a warming process.
B)a cooling process also.
C)neither of these

Question 16

When fast-moving water molecules collide they tend to

A)rebound without sticking.
B)stick.
C)both of these
D)neither of these

Question 17

The toy drinking bird nicely illustrates

A)evaporation.
B)condensation.
C)both of these
D)neither of these

Question 18

When a geyser erupts, pressure at its bottom

A)increases.
B)decreases.
C)is unaffected
D)all of the above
E)none of the above

Question 19

A canteen that is wet on the outside results in water inside that is

A)warmer.
B)cooler.
C)both of these
D)neither of these

Question 20

When slow-moving water molecules collide they tend to

A)rebound without sticking.
B)stick.
C)both of these
D)neither of these

Question 21

Water can be brought to a boil by

A)applying heat.
B)reducing air pressure on its surface.
C)both of these
D)neither of these

Question 22

The temperature at which water freezes is the same as the temperature at which

A)ice melts.
B)water boils in a pressure cooker.
C)both of these
D)neither of these

Question 23

An inventor discovers a harmless and tasteless salt, which when added to water changes its boiling point. The market value for this salt will be better if the salt

A)lowers the boiling point of water.
B)raises the boiling point of water.
C)either raises or lowers the boiling point, as the food would be cooked either way.
D)none of the above

Question 24

Foreign ions introduced to water

A)lower the freezing point of water.
B)raise the freezing point of water.
C)do not affect water's freezing point.

Question 25

Compared with sea-level cooking, in cooking eggs by boiling in mountain regions you should boil the eggs

A)with a hotter flame.
B)for a shorter time.
C)for a longer time.
D)all of the above
E)none of the above

Question 26

A good cook knows that the temperature of violently boiling water is

A)higher than that of simmering water.
B)the same as that of simmering water.
C)actually lower than 100°C.
D)neither of the above

Question 27

A geyser such as Old Faithful in Yellowstone Park is similar to a

A)vacuum bottle.
B)canteen.
C)coffee percolator.
D)teakettle.
E)vat of molten lead.

Question 28

The temperature at which a liquid freezes is

A)affected by foreign ions.
B)the same temperature at which its solid form melts.
C)both of these
D)neither of these

Question 29

Compared to sea level, water in an open pot in the mountains boils at

A)a higher temperature.
B)a lower temperature.
C)the same temperature.
D)none of the above

Question 30

Water in a car radiator sometimes boils explosively when the radiator cap is removed, which is due to sudden

A)rapid evaporation.
B)reduced pressure.
C)excess condensation.
D)excess vaporization.

Question 31

When heat is added to boiling water, its temperature

A)increases.
B)decreases.
C)remains unchanged.
D)none of the above

Question 32

In mountain regions, food cooked in boiling water cooks slower than when cooked at sea level. If the temperature beneath the pot of boiling water is increased, the food will cook

A)faster.
B)slower still.
C)both of these
D)neither of these

Question 33

Increased air pressure on the surface of hot water tends to

A)prevent boiling.
B)promote boiling.
C)both of these
D)neither of these

Question 34

For increased atmospheric pressure, the boiling point of water

A)goes down.
B)rises.
C)remains at 100 degrees C.

Question 35

In one word, how can water in the power plant of a nuclear submarine far exceed 100°C?

A)conductivity
B)evaporation
C)condensation
D)pressure
E)vaporization

Question 36

Hydrothermal vents deep beneath the ocean surface attain temperatures far above 100°C due to

A)higher salt content.
B)reduced salt content.
C)greater pressure.
D)all of the above
E)none of the above

Question 37

Water can be turned to ice by

A)lowering the surrounding air pressure.
B)extracting energy.
C)both of these
D)neither of these

Question 38

Morning dew on the grass is a result of

A)evaporation of water.
B)the open-structured form of water crystals.
C)air pressure on water vapor.
D)slow-moving water molecules sticking to one another.

Question 39

Food in a pressure cooker is cooked faster due to

A)higher temperature.
B)greater rate of bubble formation in the water.
C)energy transfer in the water.
D)all of the above
E)none of the above

Question 40

The addition of salt to water affects its

A)crystal composition.
B)freezing point.
C)viscosity.
D)liquidity.
E)none of the above

Question 41

Dean teaches that the phenomenon of regelation is due to the

A)freezing point of water.
B)melting point of ice.
C)open-structured nature of ice crystals.
D)high specific heat of water.

Question 42

When vapor transforms to a plasma, energy must be

A)absorbed by the vapor.
B)released from the vapor.
C)both of these
D)neither of these

Question 43

When a vapor condenses, energy is

A)absorbed by the vapor.
B)released from the vapor.
C)both of these
D)neither of these

Question 44

If bits of the coals do not stick to your feet while walking barefoot on red-hot coals, it would be best if your feet are

A)wet.
B)dry.
C)warm.
D)cold.
E)very hot.

Question 45

When liquids change to a solids, they

A)absorb energy.
B)release energy.
C)both of these
D)neither of these

Question 46

When a solid melts, energy is

A)absorbed by the solid.
B)released by the solid.
C)both of these
D)neither of these

Question 47

When a gas is changed to a liquid, the gas

A)releases energy.
B)absorbs energy.
C)both of these
D)neither of these

Question 48

When you walk barefoot on red-hot wooden coals it is best if

A)no pieces of metal are among the coals.
B)you walk slowly to demonstrate your courage.
C)you impress your friends by carrying away bits of wood between your toes.
D)all of the above
E)none of the above

Question 49

As a block of ice at 0°C melts, the block absorbs energy

A)and decreases in temperature.
B)and increases in temperature.
C)without a temperature change.
D)all of the above
E)none of the above

Question 50

To illustrate regelation with ice it is important that a

A)wire is used.
B)string is used.
C)either of these
D)none of the above

Question 51

When steam condenses, the surrounding air is

A)cooled.
B)warmed.
C)both of these
D)neither of these

Question 52

When moth balls sublime to gas they

A)absorb energy.
B)release energy.
C)both of these
D)neither of these

Question 53

Melting snow tends to

A)warm the surrounding air.
B)cool the surrounding air.
C)neither of these

Question 54

To melt ice, add

A)temperature.
B)energy.
C)force.
D)time.

Question 55

You can add heat without raising temperature to

A)ice.
B)boiling water.
C)both of these
D)neither of these

Question 56

The most responsible factor for whether a substance takes the phase of solid, liquid, gas, or plasma is its

A)composition.
B)atomic shell configuration.
C)temperature.
D)none of the above

Question 57

When ice crystals form in clouds, the surrounding air

A)warms.
B)cools.
C)neither of these

Question 58

When water freezes, the surrounding air is

A)cooled.
B)warmed.
C)both of these
D)neither of these

Question 59

During snow fall, the surrounding air is

A)cooled.
B)warmed.
C)both of these
D)neither of these

Question 60

When a solid is changed to a liquid, the solid

A)releases energy.
B)absorbs energy.
C)both of these
D)neither of these

Question 61

To turn 50 grams of boiling water to steam requires

A)50 calories.
B)500 calories
C)540 calories.
D)more than 540 calories.
E)none of the above

Question 62

Stored potatoes, beets, and rutabagas in an unheated well-insulated room can be protected from freezing by having in the room

A)blocks of foam plastic.
B)large tubs of water.
C)an ample supply of fire wood.
D)none of the above

Question 63

A heat pump can

A)cool an environment.
B)warm an environment.
C)both of these
D)neither of these

Question 64

In a heat pump, warming is accomplished when

A)condensation occurs in its coils.
B)vaporization occurs in its coils.
C)both of these
D)neither of these

Question 65

Which involves a larger number of calories?

A)the condensation of 1 gram of steam at 100°C to water at 100°C
B)the cooling of 1 gram of water at 100 degrees Celsius to 1 gram of ice at absolute zero
C)both the same
D)none of these

Question 66

The cooling effect inside a refrigerator is produced by

A)an electric motor that converts electrical energy to internal energy.
B)compressing the refrigeration gas.
C)vaporizing the refrigeration liquid.
D)proper insulation.
E)exchanging warmer air with colder air.

Question 67

To melt 50 grams of 0-degree-Celsius ice requires

A)25 calories.
B)50 calories.
C)80 calories.
D)none of the above

Question 68

Ice is put in a cooler to cool the contents. To speed up the cooling process, the ice can be

A)wrapped in newspaper.
B)drained of water periodically.
C)kept away from the food.
D)broken into smaller pieces.
E)none of the above

Question 69

In a heat pump, cooling is accomplished when

A)condensation occurs in its coils.
B)vaporization occurs in its coils.
C)both of these
D)neither of these

Question 70

Which will melt more ice when placed on its surface, a kilogram of wood or a kilogram of iron of the same high temperature?

A)1 kg of wood.
B)1 kg of iron.
C)both the same
D)neither of these

Question 71

Stored potatoes, beets, and rutabagas freeze at temperatures below zero degrees Celsius (rather than at exactly zero)because

A)they are good radiators of energy.
B)they are good absorbers of radiant energy.
C)the water in them contains dissolved salts and sugars.
D)they are relatively dense.
E)all of the above

Question 72

The calories needed to change 10 grams of ice at 0°C to steam at 100°C is

A)6200.
B)6400.
C)7200.
D)8000.
E)none of the above

Question 73

When water vapor changes phase to become water in a cloud, the surroundings become

A)cooler.
B)warmer.
C)both of these
D)neither of these

Question 74

When water vapor condenses on the inside of a window, the room becomes slightly

A)warmer.
B)cooler.
C)both of these
D)neither of these

Question 75

When condensation occurs inside your bedroom window, the air outside is appreciably

A)colder.
B)warmer.
C)both of these
D)neither of these

Question 76

A refrigerator

A)produces cold.
B)causes internal energy to disappear.
C)transfers internal energy from inside to outside.
D)transfers heat into cold.
E)none of the above

Question 77

The mass of ice that can be melted by 1 gram of 100°C steam is (Hint: Don't forget about hot water remaining from condensed steam.)

A)0.125 gram.
B)0.148 gram.
C)6.75 grams.
D)8 grams.
E)none of the above

Question 78

To turn 1 gram of boiling water to steam requires

A)almost as much energy as changing 1 gram of 0°C water to the boiling point.
B)as much as increasing 1 kilogram of 95°C water to the boiling point.
C)more energy than needed to turn 1 gram of absolute-zero ice to the boiling point.
D)none of the above

Question 79

Firefighters find that the temperature of burning material is best lowered when water is

A)used in small amounts.
B)pointed away from the flames.
C)sprayed as a fine mist.
D)salted.

Question 80

To increase the temperature of 50 grams of water by 2 Celsius degrees requires

A)0.04 calorie.
B)2 calories.
C)4.19 calories.
D)25 calories.
E)100 calories.