9. Oxygen gas stored at a pressure of 200atm at 300K in a cylindrical vessel of diameter 0.2 meters and height 2 meters. The van der Waals constant for oxygen are a=1.36 L2atm/mole2 and b=0.0318L/mole. The mole of oxygen gas in a cylinder vessel is moles. (A) 565 (B) 353 (C) 232 (D) 141 (E) 102 10. Which one of the following descriptions on the reversible heat transfer is correct? (A) Reversible heat flow is degraded as a maximum work performed in a system. (B) The heat transfer is so fast that the system remains in equilibrium throughout the process. (C) The process from an initial state to a final state can be returned when a maximum work is performed. (D) The system or the surroundings suffer an overall change