申論題

12. (a) A sample of ideal gas at 244 K and 2.00 atm expands from 10.0 L to 20.0 L by two different paths. Path A has two parts. In the first step. the gas is cooled at constant volume to 1.00 atm. In the second step. the gas is heated and allowed to expand against a constant external pressure of 1.00 alm until its volume is 20.0 L and T = 244 K. Path B is an isothermal. reversible expansion to reach a final pressure of 1.00 atm. Calculate for each path (i) the work done. (ii) the heat transfered. and (iii) the change in internal energy. (b) Discuss the difference in the calculated results obtained in (a) between Paths A and B and explain how the concept of state function is revcaled. (c) Can the results obtain in (a) be used to support the first law of thermodynamics? Explain. (13%)