Your report should contain the usual brief intro (what was being studied and how it was studied), as well as the usual brief methods section (don't forget to make a proper reference to the lab manual!)
Part 1: Boyle's Law
Export your Logger Pro pressure-volume data into Excel. You'll probably want to convert pressures from kPa into atm and volumes into liters before plotting. Here's a sample of what Fig 1 should resemble:
Fig 2 should be a plot of pressure vs 1/volume, as shown here. Fit a trendline to the data and print the equation of the trendline on the plot:
Next, calculate moles of air in the syringe. Use your first pressure-volume data pair (pressure in atm, volume in liters.) Assume ideal gas behavior. If you didn't measure room temperature, use 21.5oC for T (we measured it.) You should get something on the order of 7x10-4 moles of air.
An interesting exercise to do now: Boyle's Law states that PV=Constant for a fixed quantity of gas at constant T. Use excel and each of your P-V points to see if P*V is constant to at least a few decimal places for all of your data. Comment on this in your discussion.
Another interesting exercise: the ideal gas law states that P = nRT/V. The plot above (Fig 2) of P vs 1/V is linear; therefore, for an ideal gas, the slope of this plot should equal nRT. You calculated moles of air (n) above, and you know the temperature. Set nRT = slope of the trendline, and solve for R (the data set here gave 0.07606 L atm/mol K. Calculate R from your data and compare your value to 0.08206 Liter atm/mol K.)
Part 2 Pressure-Temperature relationship
Plot your data as pressure (atm) vs temperature (oC) and pressure vs Kelvin temperature (K = oC + 273.15). These plots are shown as Figs 3 and 4.
The relationship between P and T is nominally linear, so we write P=CT, where C is a constant. Calculate the value of the constant C for each of your P-T data pairs (Take P/T=C) and comment on how constant this quantity remains through the experiment.
Use the P vs Kelvin plot to calculate a value for absolute zero. Use the equation of the trendline to find the temperature (X-value) where the pressure (y-value) equals zero (i.e., in the trendline on Fig 4 above, set y=0 and solve for x.) What value do you obtain?
Also use the equation of the trendline to predict the pressure at 200 K and 400 K (plug the temperatures in for x and calculate the pressures.) What happens to the pressure when the temperature is doubled?
In your discussion, please mention why pressure increases with temperature - propose an explanation in terms of the kinetic energies of the particles which make up the gas.
