Do NoW1. ANSWER ANALYSIS QUESTIONS 1 AND 2

FROM THE PROPERTIES OF GASES LAB2. IF TIME ALLOWS, BEGIN ANSWERING

CLAIMS AND EVIDENCE QUESTION

Investigating Properties of

Gases

Testable QuestionWill it be possible to make observations about the properties of gases(pressure, volume, and temperature) on a macroscopic level?

Station 11. Draw air into the syringe,

plug the opposite end, and push on plunger.

2. How does this station demonstrate that air is matter?

3. How is pressure related to volume?

There’s resistance to pushing the plunger, thus demonstrating that gas moleculesare taking up space in the syringe(volume) and can be compressed(pressure).

The more pressure exerted by the plunger, the less volume the gas molecules take up.

Station 21. Submerge one balloon in

ice water, and another balloon in hot water.

2. How does this station demonstrate that air is matter?

3. How is temperature related to volume?

Here we find that the temperature of a gas relates to its volume. When a balloon is Submerged in cold water, it shrinks. When a balloon is submerged in hot water, itexpands.Therefore, as temperature increases, the volume of a gas increases!

Station 31. Take the mass of an

inflated balloon, and then take the mass of a deflated balloon.

2. How does this station demonstrate that air is matter?

3. Does air have mass?Here the balance revealed that the inflated balloon had a mass of .2 grams larger than the deflated balloon. Yes, air molecules definitely have mass!

Station 41. Insert the rounded end of a

deflated balloon into a two liter bottle. Wrap balloon lip around lid and attempt to inflate.

2. How does this station demonstrate that air is matter?

3. Does air occupy space?When we tried to blow up the balloon, it would not inflate. This was due to air molecules already occupying the 2 liter bottle. Once again, pressure is related to volume. Air in the bottle is being compressed (volume decreases), and will therefore exert more pressure on the balloon.

Station 51. Invert an empty drinking

glass and submerge in water. Slowly tilt glass.

2. How does this station demonstrate that air is matter?

3. Does air occupy space?

When the cup is submerged, water does not initially enter the glass showing that air occupies space. When the glass is tilted, air is allowed to escape, allowing water to enter.

Station 61. Fill a test tube with water

and cap with plastic wrap. Submerge in water, and remove plastic wrap.

2. How does this station demonstrate that air is matter?

3. Does air exert pressure?When the plastic wrap was removed, the water remained in the test tube suggesting pressure is exerted in all directions and supports water’s weight.

Station 71. Plug hole in water bottle,

fill with water, and replace cap. Unplug hole and immediately remove cap.

2. How does this station demonstrate that air is matter?

3. Does air exert pressure?

You may have noticed that none or a very small amount of water escaped the hole when first unplugged. When the cap of the water bottle was removed, however, the water in the bottle experienced atmospheric pressure from above, allowing water to escape.

Station 81. Allow 10 ml of water to boil

in a soda can. Immediately invert can and submerge in cold water bath.

2. How does this station demonstrate that air is matter?

3. Does air exert pressure?

You may have seen the inverted can collapse once in contact with cold water. Water vapor generated by boiling displaces most air in the can. Upon cooling, water vapor condenses (into a liquid; like a cloud transforms into rain), producing a vacuum in the can. External pressure becomes greater than the pressure in the can and crushes it.

Extension Question

With your partner, answer:

Using what you know about the properties of gases, why does a hot air balloon work?

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