A rigid container with volume 7 ft3 is divided into two equal volumes by a partition. Both sides contain nitrogen, one side is at 300 lbf/in.2, 400 F, and the other at 30 lbf/in.2, 200 F. The partition ruptures, and the nitrogen comes to a uniform state at 160 F. Assume the temperature of the surroundings is 68 F, determine the work done and the net entropy change for the process.