Example Problem with Complete Solution

1C-3 : Intensive Properties and the State of a System 2 pts
Can pure liquid water exist at 99oC and 1 atm with a density of 0.980 g/cm3? Explain your reasoning.
 
Read: Not much to say here.
Given: T 99 oC r 0.98 g/cm3
P 1 atm
Find: Can pure liquid water exist under these conditions?
Assumptions: None.
Equations / Data / Solve:
Answers: No.
The state of a pure substance that exists in a single phase is uniquely determined when 2 intensive properties are known. Here, the values of 3 intensive properties are specified. Any one of the three could be considered too much, extraneous or redundant information. For example, at the given T & P, the density of liquid water is 0.959 g/cm3, not 0.980 g/cm3. Similarly, liquid water at the given T & density exists at a pressure of about 0.471 atm, not 1 atm.