At what state is ammonia when it is at 85°F and 140 PSIG?

When ammonia is at a state of 85°F and 140 PSIG, it is considered superheated. Superheated vapor occurs when a substance is heated beyond its boiling point at a given pressure. In the case of ammonia, the boiling point at 140 PSIG (approximately 64.3 psi absolute) is higher than 85°F, meaning it has transitioned from saturated vapor to superheat as it continues to absorb heat without increasing pressure or condensing back into a liquid.

Saturated states refer to conditions where the substance is at the boiling point for the given pressure. Since the conditions provided indicate a temperature that is above the saturation temperature for the given pressure, ammonia cannot be in a saturated state.

Sub-cooled refers to a liquid that is below its saturation temperature at a given pressure. Since the given temperature is above the boiling point at that pressure, ammonia is not in a sub-cooled state.

Trans-critical states typically refer to conditions involving substances that are in a supercritical state, often involving pressures above the critical pressure and temperatures above the critical temperature. In this situation, ammonia does not reach those thermodynamic limits.

Thus, the conditions provided indicate that ammonia is indeed superheated at 85°F and 140 PSIG.