Chapter 6, Problem 113MP

A gaseous material XY(g) dissociates to some extent toproduce X(g) and Y(g):

$\text{XY(}g\text{)}\rightleftharpoons \text{X(}g\text{)+Y(}g\text{)}$

A 2.00-g sample of XY (molar mass $\text{=165 g/mol}$ ) isplaced in a container with a movable piston at 25°C. Thepressure is held constant at 0.967 atm. As XY begins todissociate, the piston moves until 35.0 mole percent ofthe original XY has dissociated and then remains at aconstant position. Assuming ideal behavior, calculate thedensity of the gas in the container after the piston hasstopped moving, and determine the value of K for thisreaction at 25°C.