In today's class, we first put a tea can into hot water. It imploded. We assume it depends on the pressure change inside the can due to the water's temperature. Since the temperature goes up, gas wanted to escape the can. And the pressur- e inside the can decreased.
Then ,professor Mason used a fire to heat up the can. We see the same consequence.
How does the pressure of a gas depend on its volume at a constant temperature? A syringe connected to am electric pressure sensor can be used to measure how a change in pressure affects the volume at room temp. We have a syringe which is 20cc, a computer based system and a pressure sensor.
We increment the syringe 2 cc each time and record the pressure at the moment on logger pro. The graph shows the relation between pressure and volume, which is reciprocal, or inversely proportional.
This is the graph for the relation between P and V in the experiment.
We also want to measure how gas pressure depends on its temperature. In other words, we should determine P vs T curve at constant volume and display the result using computer.
The flask contains our test volume of gas(air).
Using fire to heat the flask.
On logger pro, we see the graph: Pressure is directly proportional to temp.
We find the unit for pressure, kg m^2/s^2
At last, we find the relations between volume and temp. by heating ip the flask and watch the water level's change inside the tube.
Syringe volume change when putting flask from cold to hot water.
We draw the graph V and T. Volume is also directly proportional to the temp.
We deduct the relationship between kB and R
We solve a problem using ideal gas law.
Finally, we have an interesting experiment demonstrating how pressure will affect the volume. By pumping out the air inside the big glass container, the marshmallows all grow bigger and scarier, This is because the pressure outside the marshmallow is decreasing.
The marshmallow becomes chewier! cuz air escape
We solve a balloon problem using ideal gas law.
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