GenESS lab Properties of Air (1)

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Name:________________________________________________________ pd:______ date:_______________________________

Exploring the Properties of Air Lab

Part 1: Measuring a parcel of air.

1.Using a balloon and a scale, determine the mass of a volume of air in grams.

a.) Find the mass of the balloon empty b.) Blow the balloon up and tie it. Now find the mass of the balloon filled with air. c.) Subtract (Find the Difference) between the two masses.

2 . Using a string and ruler, estimate the diameter of your balloon in centimeters .

Data table

1

Mass of the balloon

( uninflated ) (g) inflated )

3

Mass of air inside the balloon (g)

( row 2 – row 1 )

4

5

Estimated diameter of balloon

(cm)

Total mass of air contained in this column of atmosphere ( row 3 x row 5 )

1

Did you know……

Anything with mass has weight, and we know air has mass because (for example) we can feel it when the wind blows. The total weight of the atmosphere exerts a pressure of about 15 pounds per square inch at sea level. You don't notice this weight, however, because you are used to it. You have equal amounts of air pressure pushing on your body from all sides. Gravity and Air Pressure work together, Air at sea level is being compressed by all of the air above it, weighing it down and increasing its density . The higher you go in the atmosphere (altitude) air pressure deceases.

Discussion questions:

1. If air has mass and pressure, describe why you are not currently getting crushed by it! USE COMPLETE SENTENCES.

2. Would you expect the mass of the air column to be greater or less on top of Mt.

McKinley (6,190 m above sea level), as compared to Death Valley (86 m below sea

level)? Why?

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Part 2: What is the relationship between air pressure and temperature?

1.

Place 20 ml of water in a can.

2.

Heat the can on a hot plate until you see steam coming out of the top. In the left box, make a model of what you observe. (be sure to label the movement of water and atmospheric gases in and/or out of the can.)

3.

Use beaker tongs to carefully turn the can upside down into a container of water.

4.

Record your results as a labelled model in the right box. Use arrows to indicate how water moves.

Analysis:

1.

After you heat the can and flip it upside down into the water, the air pressure inside the can is _____________________ and the air pressure outside is __________________________.

2.

Why does water flow into the can from the bowl of water?

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3.

Just like the water, air will flow from areas of __________________ pressure to areas of

_______________ pressure.

4.

The can on the hot plate is an example of what type of thermal energy?

___________________________

5.

The water inside the can boiling due to the heat plate is an example of what type of thermal energy?

___________________________

6.

If you were to hold your hands near the hot plate to feel the heat coming off of it, this would represent what type of thermal energy?

__________________________________

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Name:______________________________________________________ pd:________ date:___________________________________________

Part 3: Is there water in the air?

1. Half fill a glass with water . Record the temperature of the room and the water.

2. Add ice cubes until the glass is full. Record the temperature of the water at 10 second intervals.

3. Observe the outside of the glass.

4. Note the time and the temperature at which condensation occur on the outside of the glass .

5. Once condensation has occurred the data collection can stop.

Data table: Indoor room temp = _______ o C temp water = _______ o C

Time s

Temp o C

Change? no / yes

Time s

Temp o C

Change? no / yes

Time s

Temp o C

Change? no / yes

Time s

Temp o C

Change? no / yes

0 90 200 290

10 100 210 300

50

60

70

80

10

20

30

40

20

30

40

50

60

110

120

130

160

170

220

230

240

250

260

310

320

330

340

350

70 180 270 360

80 190 280 370

4. Repeat the investigation outside. Record the temperature of the water and the air outdoors.

Data table Outdoor temp = _______ o C temp water = _______ o C

Time s

Temp o C

Change? no / yes

Time s

Temp o C

Change? no / yes

Time s

Temp o C

Change? no / yes

Time s

Temp o C

Change? no / yes

0 90 200 290

160

170

180

190

100

110

120

130

210

220

230

240

250

260

270

280

300

310

320

330

340

350

360

370

5

Analysis

1. Compare and contrast Describe how the atmosphere outside of the glass changed to produce condensation.

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2. Relate your experiences of wet grass in the early morning to the lab conditions that allowed the atmosphere to reach its “dew point” (What happened to the air to form condensation?)

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