What characterizes a superheated vapor?

A superheated vapor is characterized by being a dry vapor that exists at a temperature higher than its saturation temperature. At this state, the vapor is not in equilibrium with its liquid phase; hence it cannot condense back into a liquid, even if the pressure is increased.

In a superheated state, the vapor has absorbed additional heat beyond what is necessary to keep it in the gaseous state, which allows it to maintain its gaseous form under conditions where it would otherwise condense if it were in equilibrium with its liquid phase. This distinct property makes superheated vapor useful in various industrial applications where a dry, high-temperature vapor is needed, such as in turbines or heat exchangers.

The other answer choices focus on different states or conditions of vapor and liquid, which do not accurately reflect the properties of superheated vapor. Specifically, they describe conditions that would not provide the high thermal energy characteristics of superheated vapor. This clarity in defining superheated vapor helps in understanding its behavior and applications in thermal systems.