A stationary closed system with ideal gases is subjected to the Carnot gas cycle. (a) (i) Sketch a cycle on a pressure-volume diagram. (5 marks) (ii) Briefly explain how the processes could be operated to make the cycle. (i) Give the definition of entropy, and explain how it is used to examine a thermodynamic process. (5 marks) (ii) The change in the Gibbs free energy of the system that occurs during a reaction is used to predict the possible direction of the reaction. Explain it and examine whether the rule used is consistent to that for a thermodynamic process. (3 marks)