What is the state of ammonia at 115°F and 251 PSIG?

To determine the state of ammonia at 115°F and 251 PSIG, it’s essential to refer to the ammonia saturation table or phase diagram. At a given pressure, these resources provide the saturation temperature, which indicates the temperature at which ammonia transitions between liquid and vapor.

At 251 PSIG, the saturation temperature for ammonia is significantly lower than 115°F. Since the temperature of the ammonia is higher than its saturation temperature, it indicates that the ammonia is in a state where it is entirely in vapor form without any liquid present; hence, it is classified as superheated. Being in a superheated state means that the substance is heated beyond the boiling point at a given pressure.

The correct characteristic of the state at this temperature and pressure pairing is indeed superheated as per the thermodynamic properties of ammonia. This understanding is critical in processes where ammonia is used as a refrigerant, as the state of the refrigerant can influence the efficiency of the system.

Therefore, the selection of the saturated state is not accurate in this context, as the substantial understanding of how ammonia behaves under pressure and temperature conditions leads to classifying it as superheated, based on the provided values.