Lab Report 2
10/6/14
Introduction
When applying scientific laws in lab, it is important to understand the relationship between the different variables at play. Using the Ideal Gas Law the following behaviors, Pressure (P), Volume (V), Temperature (T), and quantity in moles (n) relationships are examined between each other. However, before using these terms, the assumptions under the ideal gas law—that molecules don’t interact when in a gas state and that volume occupied by molecules is negligible—were taken into consideration The ideal gas laws states that the interdependency of the variables P,V,n and T can be understood through PV = nRT, regardless of the identity of the gas. The three more fundamental equations correspond to the three experiments that were run in this lab and they are called Boyle’s law, Charles’ law and Gay- Lussac’s law.
Procedure
For experiment 1, the first step was to step up the equipment and select the pressure gauge to zoom in on the measuring devices. Next, weights were added to the piston by clicking on it and then noting the height as seen on the ruler. Next, this procedure was repeated again until four different measurements were taken for four different weights.
For experiment 2, the first step was to set up the equipment and select the pressure gauge to be able to zoom in the measuring devices. Next, the heat knob on the hotplate was turned on and the height change was seen through the ruler and the change in the pressure from the pressure gauge was noted as well.
For experiment 3, the pressure gauge was selected to zoom on the measuring devices. The knob on the hotplate was turned on and the change in pressure on the pressure gauge and the change in the temperature from the thermometer was noted. The temperature increased by 10 degrees Celsius every time the knob was selected. This was repeated 5 times, therefore getting 5 temperature readings and 5 pressure readings.
For experiment 4, a large syringe was obtained and its mass was measured. Next, the syringe was filled with one of the provided gas samples (Carbon Dioxide, Canned Air, and Atmospheric Air) and the cap was placed on the syringe. The mass of the filled syringe was taken, and the analysis was repeated three times.
For Experiment 5, different mathematical procedures were conducted. First, the real data for various gases was taken and the volume for the various gases was plotted against it on a scatter plot. Next, the Z values were calculated for both the real and ideal gas law data by dividing pressure and volume over Avogadro’s number and temperature. Lastly, the Van der Waals Equation was used to calculate the Van der Waals volume and pressure for the non-ideal gases.
Questions
Experiment 1:
Explain the setup of the experiment. What equipment was used? What were the initial readings on the instrumentation?
The experiment objective was to see the relationship between pressure and volume. By adding weights to the cylinder the pressure would change. Some of the equipment that were used are a cylinder, pressure gauge, weights, and a ruler. But since the experiment was done online not all the equipment used is known. The initial readings on the instrument reading on the pressure gauge was about 616.4 Torr without any weights on the cylinder.
When weights were added the volume decreased. In this experiment, what happens to pressure when the volume is decreased? What is happening to the gas particles at an atomic level?
When weights were added the pressure increased, and the gas particles at atomic level a colliding more frequently and are interacting more.
Compute the volume of the cylinder (in L) at each point in the experiment. Diameter can be found in the experimental section.
BOYLES
Weight
Length Cylinder (cm)
Pressure (atm)
Volume(L)
0
15.21
616.5
1084.902
1
14.97
626.8
1068.518
2
14.73
637.2
1043.586
3
14.51
647.5
1032.901
4
14.29
657.8
1014.380
5
14.04
668.1
1009.393
Experiment 2:
Explain the setup