Final answer:
The initial state of water is a subcooled liquid at 4 bar.
Step-by-step explanation:
The initial state of water depends on its temperature and pressure. At normal temperatures (between 0°C and 100°C), water is in a liquid state. So, the initial state of water is a subcooled liquid at 4 bar. As the temperature increases beyond 100°C, water transitions into a superheated vapor state. At pressures below its boiling point, water can exist as a vapor, and at higher pressures, it can condense into a liquid or even solidify into ice.