Final answer:
The initial state of a 2m³ rigid insulated tank can vary between being filled with saturated water vapor (gas state), liquid water (liquid state), being empty (vacuum or containing air in gas state), or containing a mixture of water and air (both liquid and gas states).
Step-by-step explanation:
The initial state of the 2m³ rigid insulated tank depends on the specific content within the tank. If the tank contains saturated water vapor, this implies that it is in a gas state and is at the temperature where water transitions from liquid to gas (boiling point) under the tank's pressure. If the tank contains liquid water, this signifies that the water is in a liquid state, which has a definite volume but takes the shape of the tank. In the case where the tank is empty, there would be a vacuum or it might contain air, which would be a gas state. Lastly, if the tank holds a mixture of water and air, both liquid and gas states are present with water in liquid form and air in the form of a gas, likely at a pressure above the saturated vapor pressure of the water. Understanding the state of matter inside the tank is important for thermodynamic analysis and applications related to energy systems.