## Two-Phase Systems

Consider an insulated storage tank contains an element in a half liquid and half vapor by volume equilibrium state. If a small amount of vapor is released without adding heat, what will happen to the system?

Hint
Hint 2
Specific volume is an intrinsic property of a substance that describes the ratio between a substance's volume (V) to its mass (m).
$$v=\frac{V}{m}$$$The overall mass inside the tank is reduced slightly as vapor is released. Since the tank's vessel maintains its shape, volume is constant. As a result, the specific volume inside the tank must increase to adjust for the lower vapor amount, which can only occur if some liquid evaporates. Remember, specific volume is an intrinsic property of a substance that describes the ratio between a substance's volume (V) to its mass (m). $$v=\frac{V}{m}$$$
Some liquid evaporates.