Two chambers are separated by a partition. One of the chambers is evacuated, and the other has a volume of 1 m³ and contains steam at T = 500°C and P = 10 bar. The partition is removed, allowing the gas to expand into the evacuated chamber. No heat transfer occurs with the surroundings. The final steam pressure is P = 4 bar. Find

A. The mass of steam.

B. The volume of the chamber that was initially evacuated.

C. The change in entropy of the universe resulting from the process.

D. Re-do parts A–C, but this time, instead of steam, assume the 1 m³ chamber was filled with an ideal gas with C_p* = (7/2)R.