(c) Question three (a) With the help of examples, differentiate between intensive and extensive properties. [3 marks] (b) Calculate the amount of work done by 2 moles of an ideal gas at 500 K in a reversible isothermal expansion from 2.0L to 20L [3 marks] Briefly explain the term entropy of a system? [2 marks] (d) At 1 atmosphere, Toluene (methyl benzene) boils at 110C and its latent heat of vaporization is 33470 J/mol. Estimate the entropy change when Toluene is heated from 100C to 130C assuming that in this temperature range the heat capacities (Cp) of the liquid and the vapour are 180JK-'mol-and 120JK:mol respectively. [8 marks] (e) Show that Cp and Cv are connected by the equation Cp-Cy = R where Cp and Cy are the specific heats of a gas at constant Pressure and volume respectively and R is the universal gas constant (R = 8.314 Jmol'k'). [4 marks]