Final answer:
Hospital oxygen concentration typically varies; atmospheric air tapped from the wall is about 21%, while medical-grade oxygen used for patient care often approaches 90%-100% concentration.
Step-by-step explanation:
The oxygen concentration coming out of a wall tap can vary depending on the hospital's supply system. Hospital oxygen is typically a high-grade, near-100% concentration, but because it is delivered to multiple points and utilized for various needs, the delivered concentration can vary. If the question is directly referring to the environmental air which is tapped from the wall, then 21% is the approximate oxygen concentration in the atmosphere.
However, for medical-grade oxygen, especially when delivered from a cylinder or central supply system, it can approach 90%-100% concentration. The context of the question indicates an interest in medical applications for supplemental oxygen. Medical oxygen is provided to patients at varying levels of purity, but often close to 100% to ensure they receive the oxygen necessary for proper bodily function, especially when their health condition prohibits them from breathing normal atmospheric air effectively.