PASCO TD-8595 Absolute Zero Apparatus - Manual (Page 9)

Absolute Zero Apparatus Model No. TD-8595
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4. Place the sphere of the apparatus in the ice-water bath, and connect the hose fitting to the
Pressure Sensor. Keep the sphere completely submerged, click the Start button, and
watch the Digits display of temperature.
5. When the temperature stops changing (in the hundredths place), click on the Keep button.
Do not stop recording.
6. Place the sphere in the room temperature bath and repeat step 5.
7. Place the sphere in the hot-water bath and repeat step 5.
8. Click on the Stop button to end recording. Save this data to disk.
9. Click on the Fit menu button and select a linear curve fit. The y-intercept is your value
for absolute zero.
10. Repeat the above procedure using a different amount of gas (n) in the sphere. This time,
start with the room temperature bath. Disconnect the hose fitting from the Pressure
Sensor. Place the sphere in the bath and re-connect the fitting. Take readings for all three
baths as before. Plot this data on the same graph, click on the Fit menu button, and
choose a linear curve fit. You will now have two lines with different slopes, but about the
same intercept.
11. Repeat the above procedure again, starting this time with the hot-water bath. Take the
readings in the other two baths, and plot this data on the same graph.
12. Average your three values, estimate the uncertainty, and round your answer to the
appropriate number of significant figures. Compare the average of your three values for
absolute zero with the accepted value of -273
° C.
13. Measure the volume of the sphere. Using the slope of each of the lines, determine the
number of moles of gas in the container for each of the three runs.