A gaseous material XY(g) dissociates to some extent to produce X(g) and Y(g):
XY(g) ⇌ X(g) + Y(g)
A 2.00- g sample of XY (molar mass = 165 g/ mol) is placed in a container with a movable piston at 25oC. The pressure is held constant at 0.967 atm. As XY begins to dissociate, the piston moves until 35.0 mole percent of the original XY has dissociated and then remains at a constant position. Assuming ideal behavior, calculate the density of the gas in the container after the piston has stopped moving, and determine the value of K for this reaction at 25oC.