Mr. Kostecki "The Ideal Gas Law Lab" Section 1

The Ideal Gas Law
Experimenters: Eric Tuvell, Molly Lorenz

Main Purpose: Using the Ideal Gas Law, we should be able to understand the different relationships between pressure, temperature, volume, and how they work ideally at a molecular level.

1) P&V Materials Used:
Gas Law Apparatus Syringe
Short Piece of Tygon Tubing
Computer Based Laboratory System
Pressure Sensor
RealTime Physics Heat and Thermodynamics experiment configuration files
Piece of String
Scissors

1) P&V Predictions:
Prediction 1-1: As you compress the air in a syringe by pushing the piston slowly, what will happen to the pressure? What do you think will be the mathematical relationship between pressure P and volume V?
We thought that the pressure will increase, and the relationship between pressure and volume will be inversely proportional.

1) P&V Experimental Procedure:
When the end of an unsealed syringe was attached to the pressure sensor using the Tygon tubing, the piston was started at 20 mL. Next, the file Pressure vs. Volume (L05A2-1) was opened and we recorded that the volume of the sensor was 0 cm3 for Table 1-1 (see attached). Some dimensions of the tubing we were using were given to us, but we had to account for the rest- so, using a piece of string to bend like the tubing we measure the inside diameter to be .3 cm, the length of the tubing to be 58 cm, and therefore, the estimated volume of the tubing to be 4.1 cm3. These volumes were recorded in Table 1-1 as well. Then, we slowly pushed down on the piston, and when the pressure reading was stable, we kept a data point, we repeated that 4 times. We used the fit routine, finding a relationship between P and V, and lastly, printed the graph.

1) P&V Analysis:
Question 1-1: What is the relationship between P and V? Is it proportional, linear, inversely proportional, or something else? Did this agree with your prediction?
The relationship between pressure and volume was inversely proportional and did agree with our prediction.
Question 1-2: Write down the relationship between the initial pressure and volume (PiVi) and the final pressure and volume (PfVf) for an isothermal process?
PiVi=19.665, PfVf=17.28 The initial is larger then the final.

1) P&V Conclusion:
The conclusion was that Boyle’s law was true, stating that P1V1=P2V2.