Transcript Investigating Properties of Gases

Do NoW
1. ANSWER ANALYSIS QUESTIONS 1 AND 2
FROM THE PROPERTIES OF GASES LAB
2. IF TIME ALLOWS, BEGIN ANSWERING
CLAIMS AND EVIDENCE QUESTION
Investigating Properties
of
Gases
Testable Question
Will it be possible to make observations about
the properties of gases(pressure, volume, and
temperature) on a macroscopic level?
Station 1
1. 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 molecules
are 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 2
1. 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, it
expands.
Therefore, as temperature increases, the volume of a gas increases!
Station 3
1. 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 4
1.
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 5
1. 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 6
1. 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 7
1. 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 8
1. 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?
http://videos.howstuffworks.com/howstuffworks/43how-hot-air-balloons-work-video.htm