Name:Dr. Julie J. Nazareth

Lab Partner(s):Physics 122L/132L

Date lab performed:Section:

Ideal Gas Law

Table 1: Constants for the experiment

Room Temp.,
T (°C) / Room Temp.,
T (K) / Atmospheric pressure,
P0 (mm HG) / Atmospheric pressure,
P0 (Pa) / Mass of piston,
mp (kg) / Piston Diameter
D (m) / Piston Area,
A (m2)

Table 2:

Mass added, Ma (kg) / Total mass,
M ( ) / Weight on air column, W ( ) / Total pressure of gas (air),
P ( ) / Length of air column, L ( ) / Inverse pressure, 1/P
x10-6 (m2/N)
0.0
0.020
0.040
0.060
0.080
0.100
0.120

*** Ignore formal significant digit rules and keep five or six digits for your Pressure and Inverse Pressure values so you do not round all of the detail away. ***

Graph: Plot the length of the air column versus the inverse pressure of the gas (L vs. 1/P). Make sure that the length is in units of meters (m) and the inverse pressure is in units of m2/N (1/Pa). DO NOT include the origin in your plot or you will have lots of blank space on your graph. Set up your x- and y- axes to spread your data out across most of the paper. Draw a best fit straight line to your data and calculate the slope of the line. Use algebra and the equation of a line to calculate your y-intercept (because you cannot measure it off your graph directly). Draw a small box or circle around the two points you used to calculate the slope – remember that these should not be data points. Don’t forget to title and label your graph properly.

Table 3: Results from the graph of Length versus Inverse Pressure

Slope
( ) / y-intercept
( ) / Number of moles,
n ( ) / Volume in attached bottle plus tubing,
V0 ( )

Calculations: Show the following calculations in the space provided below, or on an attached sheet of paper. Include units in your calculations. Ignore formal significant digit rules, but be reasonable with your digits. Keep five or six significant digits for the pressure and the inverse pressure (or you will round most of the detail away). Remember, keep two extra significant digits during your calculation and only round in the very last step.

  • Area of the piston (in m2)
  • Sample calculation of the weight on the air column
  • Sample calculation of the total pressure of the gas (keep five or six significant digits)
  • Slope of your plot
  • y-intercept of your plot
  • Number of moles, n, from the slope
  • Volume, V0, from the y-intercept

Don’t forget to write your summary! (Some things to think about: Does your data verify Boyle’s law? (What is Boyle’s law anyway and what specifically about your data that verifies the law?) How many moles of gas are in your lab apparatus? Does this value seem reasonable (define “reasonable”)? Did you get the expected value for V0? (What is the expected value?) If not, why do you think that is so?)

Lab: Ideal Gas LawUpdated 01/02/09