GAS THE LAWS
Physics 142L
A.
Constant Temperature (Boyle's Law)
A glass tube closed at one end is linked to a valve. The glass contains a steel ball of the same diameter as the tube which seals off nearly completely an air volume. The volume can be read on a scale mounted behind the tube. The valve has a connection to a manometer,which reads the pressure in the tube, and a hose nozzle. When the apparatus is connected to the output side of the pump the pressure in the tube can be increased; when connected to the intake side of the pump the pressure can be decreased.
manometer
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nozzle """"""'"
steel ball
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scale
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valve --"
1.
Procedure: Completely open the valve (turn fully anticlockwise) and connect the tubing to the pressure side of the pump. The ball is set to any desired scale division by slightly inclining the apparatus. (The ball seals off a gas volume in the tube of length L.) Close the valve. Increase the pressure in steps of about .1 bar. Take about five readings up to an overpressure of about 1.5 bar. Repeat the experiment now with the apparatusconnected to intake side of the pump. Again take
aboutfive readingsdownto bar.
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2.
Analysis: about.5 Graph pressure vs. VI (L is proportional to V) with elTorbars. Does a linear relation exists? Does the slope for the overpressuredata agree with the slope for the underpressure data? If not, why not? Constant Volume
B.
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The apparatus consists of a copper bulb connected to a pressure gauge and an air valve. Gas is admitted under pressure into thesystem, the bulb is subjected to different temperatures, and the resulting different pressures are read on the gauge.
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,, , copper bulb
1.
, Procedure: Put air into the bulb until the gauge ,, indicates 12PSI at room temperature. Record this , pressure and the room temperature. Submerge the air valve bulb in the follo...