Approximately how many BTU's does it take to convert 1 pound of saturated liquid Ammonia to 1 pound of saturated gas?

To understand why 561 BTU's is the correct answer for the conversion of 1 pound of saturated liquid ammonia to 1 pound of saturated gas, it is essential to consider the thermodynamic properties involved in the phase change of ammonia.

When changing from a liquid state to a gas state, a substance requires energy in the form of heat to overcome the intermolecular forces holding the liquid molecules together. For ammonia, this energy is measured as the heat of vaporization. The specific amount of energy needed to vaporize 1 pound of saturated liquid ammonia at its boiling point under normal atmospheric pressure is approximately 561 BTU's.

This amount reflects the energy required for a complete phase change without a temperature increase, demonstrating the strong intermolecular forces present in ammonia that necessitate a significant energy input for the transition from liquid to gas. This value is crucial for calculations in refrigeration and heating applications where ammonia is used as a refrigerant, and understanding these energy transfer requirements is vital for equipment design and operational efficiency.

In summary, the conversion from liquid to gas requires 561 BTU's of energy for ammonia, signifying the substantial energy required for vaporization, which is why this answer is correct within the context of thermodynamic principles.