PASCO SE-9790 STUDENT BELL JAR - Manual (Page 2)

Student Bell Jar 012-07194A
2
5 10 15 20 25 30 35 40 45 50 55 60
cc
Basic Setup and Operation
Figure 1
Assembling the vacuum pump
E
F
1. Assemble the vacuum pump as shown in Figure 1.
2. Attach part E to the connector on the top of the bell
jar. Twist to secure the connection (Figure 2).
Figure 2
Attaching the vacuum pump to the bell jar
• Press the suction cup onto the base of the bell
jar.
• Half-fill the plastic cup with very hot coffee, and
place it on the base of the bell jar (Figure 3).
4. Put the lid on the bell jar, hold it there firmly, and
pump the piston of the syringe 10 to 15 times.
Result:
• the balloon will expand
• the marshmallow will expand
• the suction cup will fall off
• the coffee will boil
Suggestion: For the coffee boiling experiment,
measure the coffee temperature before and after it
boils.
3. Do one of the following:
• Place the balloon on the base of the bell jar.
• Place a large, fresh marshmallow on the base of
the bell jar.
E
Figure 3
Completed setup for the coffee boiling demonstration
5
10
15
20
25
30
35
40
45
50
55
60 cc
cup with hot coffee
O ring
To Determine the Weight of Air
1. Find and record the original combined mass of
parts A, B, and E.
2. Evacuate the chamber and disconnect A from
E.
3. Find and record the resulting combined mass of
parts A, B, and E .
4. Subtract the resulting combined mass from the
original combined mass to find the mass of air
in the bell jar.
A
B
E