Answer
a. It would vaporize
b. It would become a solid and then a vapor
Work Step by Step
a. Initially, the water is a liquid. As the pressure is lowered, the water becomes a vapor. This happens at some pressure between 1.0 atm and 0.006 atm. At 0.004 atm, it is still a vapor.
b. Initially, the water is a liquid. As the pressure is lowered, the water becomes a solid at a pressure of 1.0 atm. It then becomes a vapor at some pressure lower than 0.006 atm. It’s hard to tell from the nonlinear scale, but it appears to become a vapor before the pressure reaches 0.004 atm.
