Determining
the Temperature of Absolute Zero Name
___________________________
1. Put your test tube into the beaker and heat
the water to boiling.
2. After the water has been boiling for five
minutes, measure its temperature.
Since the air inside the test tube is at
the same temperature as the water, record this
as the temperature of hot air : should be close to 100 oC
3. Keeping your finger
over the opening in the stopper, remove the test tube from the hot water,
turn it upside
down, and put it into the ice bath. Once
the hole in the stopper is under water
you can take your
finger off of it.
4. Let the test tube sit in the ice bath for
five minutes, then measure the temperature of the ice
bath.
Since the air inside the test tube is at
the same temperature as the water, record this
as the temperature of cold air: should be close to 0 oC _
5. After the test tube has been in the ice bath
for five minutes, reach in, put your finger over the
hole in the
stopper, and remove the test tube.
You should notice that there is now water
inside your test tube. Why did this
happen? ______
What happens to atoms as
they get colder?
6. Use your little graduated cylinder to measure
the amount of water
inside your test tube.
Since this is how much the the air shrunk when it cooled, record this as the
change in
volume: should
be less than 10 ml
7. Determine the volume of the hot air by
filling your now empty test tube with water, insert the
rubber stopper,
remove it, and use the large graduated cylinder to measure the volume.
Since this is equal to the volume of the
air before it got cold and shrank, record this as the
Since the air inside the test tube is at
the same temperature as the water, record this
as the
temperature of the hot air on your
data table.
Volume of Hot Air: should
be over 30 ml
8. Find the volume of the cold air by subtracting
the change in volume (#6) from the volume
of hot air (#7).
Volume
of Cold Air:
________________________
9. Enter your data into the Logger Pro program
and choose “linear fit”.
10. Use the space on the back side of the paper
sketch the graph as it appears on your computer
screen. Be sure to label the graph and draw the
best-fit line.
The point where the best-fit line intersects the x-axis it
the
temp that your data predicts for absolute zero
11. In the space below, write the equation for
the linear fit. Be sure to substitute
the appropriate
values for slope and y-intercept.
Volume = m (temp)
+ b (use data
form your experiment to find “m” and “b”
12. Use the equation above to solve for the
temperature (x) at which the air sample would have a
volume (y) of
zero ml.
13. According to Kelvin, the value obtained above
would be the temperature of Absolute
Zero, because any further cooling would
produce a negative volume. The accepted
value for
Absolute Zero is -273.2 oC,
how many degrees off were you?
14. Kelvin had no idea about atoms or their
jiggling, but we do. What does Absolute
Zero mean
in terms of
atomic motion?
What are the atoms doing at absolute zero?
15. Why is the Kelvin scale the better than
either the Celsius or Fahrenheit scales?
16. If you had not been careful, and some of the
water had leaked out of
your container before
found the change
in volume, would your predicted valued for the temperature of absolute
zero
have been too
hot or too cold?_____________________________
17. Use your equation to determine how cold
would it have to be (in oC) in order for
your air
sample to
be reduced to half its original volume?
Use equation to solve for a volume that is half of starting volume