Problem # p021

Phase of Water

A rigid container with a constant volume of 1 m³ is filled with 0.5 kg of water at a temperature of 30°C. To answer the following questions use the data in the tables.

Saturated liquid water :
T°Cp [MPa]v[m³/kg] u[kJ/kg]h[kJ/kg]s[kJ/(kg K)]
304.2460.0010125.78125.79 0.4369

Saturated water-vapor :
T°Cp [MPa]v[m³/kg] u[kJ/kg]h[kJ/kg]s[kJ/(kg K)]
304.24632.892416.62556.3 8.4533

Water at critical point :
T°Cp [MPa]v[m³/kg] u[kJ/kg]h[kJ/kg]s[kJ/(kg K)]
374.1422.090.003162029.62099.3 4.4298

  1. What is the specific volume of the water ?

  2. What phase is the water in ? (compressed liquid, saturated liquid/vapor mixture, or superheated vapor). What is the precise reason for your choice ?

  3. Upon heating, the temperature and pressure in the constant-volume container rise. Ultimately, the water will become either compressed liquid or superheated water. Which one is it going to be and why ?