P2A.7 Calculate the work done during the isothermal reversible expansion of a van der Waals gas (Topic 1C). Plot on the same graph the indicator diagrams (graphs of pressure against

volume) for the isothermal reversible expansion of (a) a perfect gas, (b) a van der Waals gas in which a=0 and b = 5.11x 10 (-2)dm 3 mol, -1and (c) a = 4.2 dm6 atm mol²and b= 0. The values selected exaggerate the imperfections but give rise to significant effects on the indicator diagrams. Take V, = 1.0 dm², V,= 2.0 dm², n = 1.0 mol, and T= 298 K.