a=4.6368 (atm*L^2/mol^2)
b=0.0436111 (L/mol)
From the Freon 13 Isotherm plot in the results section, one notices how well Van der Waal's equation with the above a and b parameters fits our experimental data. However, due to inconsistencies in apparatus there exist some discrepancies between expected and our estimated values for the critical temperature, pressure and volume. We calculated -27% error for our value of Tc and -140% error for Pc. These values are significantly erroneous, however, we noticed that our experimental data conformed with accepted values. We observed no phase changes above the accepted critical temperature of 29°C. Therefore, we conclude that to an extent our experimental data obeyed Van der Waals equation of state, but our estimated values suggested otherwise. Overall, we think that because this particular Central Scientific device has had an abused past it does not represent a good means for calculating the Van der Waals constants accurately.
a=5.4 (atm*L^2/mol^2)
b=0.046511 (L/mol)
From the Sulfur Hexafluoride Isotherm plot in the results section, one observes how Van der Waal's equation with the above a and b parameters fits our experimental data for Sulfur Hexaflouride. The data exhibits a decent match between the theoretical and experimental data, but it clearly isn't defined as well as our results for Freon 13. There are also some differences in our expected and experimental values for the critical temperature, pressure and volume. The error in estimated Tc is a whopping -31.7% and also -112% for Pc. Again, the accuracy of the apparatus becomes a factor, but our experimentally gathered data behaved as expected observing no isotherms above the accepted value for Tc of 45°C .