One pound-mass of water at 600 F expands against a

One pound-mass of water at 600 F expands against a piston in a cylinder until it reaches ambient pressure, 14.7 lbf/in 2, at which point the water has a quality of 90%. It may be assumed that the expansion is reversible and adiabatic.
a. What was the initial pressure in the cylinder?
b. How much work is done by the water?