Final answer:
Copper is the preferred material for a shell-and-tube condenser using sea water due to its excellent thermal conductivity and strong resistance to corrosion in marine environments. It is also compatible with NH3 as a refrigerant.
Step-by-step explanation:
When selecting a metal for a shell-and-tube condenser that will use sea water for NH3 (ammonia) condensation, it is crucial to consider the corrosion resistance of the material in maritime environments.
Copper is commonly used for this application due to its excellent thermal conductivity and corrosion resistance, especially in marine environments where sea water is involved. Therefore, the correct answer is D) Copper. Metals like black iron and galvanized steel are less suitable due to their higher susceptibility to corrosion in marine environments. Muntz metal, also known as Admiralty metal, is an alloy of copper that could be used as a substitute, but pure copper is the more typical choice.
It is also worth noting that the selection of materials goes beyond their resistance to sea water; factors like their compatibility with the refrigerant, in this case, NH3, are also important. Copper is compatible with ammonia, whereas some other metals may become brittle and fail when exposed to ammonia under certain conditions.