### Comments re Chapter 8 Problems:

 8-7 An exercise in calculating a pressure (which is high so that nonideality matters) using PV=nRT, the van der Waals equation, the Redlich-Kwong equation, and the virial equation.  All necessary equations are given in Sections 8.2 (see pg. 245) and 8.4 (see pp. 249ff).  This problem is somewhat tedious, but doing tedious problems without making mistakes is one of the skills students are supposed to learn in PChem courses.  The results are interesting.  In the answer book Levine gives the measured pressure at these conditions as 135 atm.  Please make a table of the calculated values and calculate the percent error for each. 8-40 A short problem in which the a and b parameters of the van der Waals equation, along with the critical temperature and DvapHo at the normal boiling point, are compared for pairs of chemically similar atoms or molecules.