L161PL. A Review of Graphical Analysis

The following problem is the first problem of the L161 prelab assignment. Enter your responses in the WebAssign assessment, L161PL. There are additional items related to the lab instructions.

The Problem: Pressure, P, is applied to n = 0.10 moles of a gas in a compressible, leak-free container. The temperature, T, of the gas is maintained constant. The volume, V, of the gas is measured for five values of pressure.

Pressure
(pa)		 Volume
(m3)
1.24E5 8.5E-4
1.73E5 5.6E-4
 2.23E5 4.4E-4
 2.70E5 3.3E-4
 3.27E5 2.8E-4

  1. Which variable is independent? Plot a graph of the dependent variable (DV) vs. the independent variable (IV) in Logger Pro. Select the shape that best describes the graph.

  2. If the gas is ideal, what relationship do you expect between the DV and the IV? Write your answer in the form DV = f(IV), where you provide the correct functional form together with necessary constants.

  3. Re-express the IV as needed and then graph DV vs. IV-reexpressed. How can you tell from the graph if the gas is ideal?

  4. What is the significance of the slope of the fit? That is, how does the slope of the fit relate to the known constant parameters of the system (n, T) and any fundamental constants?

  5. Ideally, why would you expect the volume-intercept of the fit to be 0? (Saying that the volume is expected to be 0 when the pressure is 0 should be obviously incorrect to you.)

  6. Write the equation of the fit.

  7. Use a coefficient of the fit to determine the temperature of the gas to the nearest 10 kelvins.


© North Carolina School of Science and Mathematics, All Rights Reserved. These materials may not be reproduced without permission of NCSSM.