an insulated tank is divided by a thin partition. (a) on the left is 0.79 mole of n2 at 1 bar and 298 k; on the right is 0.21 mole of o2 at 1 bar and 298 k. the partition ruptures. what is dsuniv for the process? (b) on the left is 0.79 mole of n2 at 2 bar and 298 k; on the righ