derive a relation for the second virial coefficient of a fluid that obeys the SWP ( square well potential model ) relation .Use data on B for methane ( in Table 5.4 ) to obtain the potential energy parameters ( sigma ) and (Epsilon) . compare your calculated values with those obtained from Lenard Jones potential model as Sigma = 4.01 A and ( Epsilon /k = 142.87 K ) . TABLE 5.4 - SECOND VIRIAL COEFFICIENT FOR SEVERAL GASES COMPOUND TEMPRETURES (K) 200 300 400 500 N2 -35.2 -4.2 9 16.9 CO2 ...... -122.7 60.5 -29.8 CH4 -105 -42 -15 -0.5 C2H6 -410 -182 -96 -52 C3H8 ...... -382 -208 -124