A system of volume V contains a mass m of gas at pressure p and temperature T. The macroscopic properties of the system obey the following relationship:   2 a p V b mRT V          where a, b and R constants. Obtain an expression for the displacement work done by the system during a constant- temperature expansion from volume V1 to volume V2. Calculate the work done by a system which contains 10 kg of this gas expanding from 1 m3 to 10 m3 at a temperature of 293 K. Use the values a = 15.7 x 104 Nm4 , b = 1.07 x 10-2 m3 , and R = 0.278 kJ/kg-K.