Which gas is noted for having a sweet odor?

Nitrous oxide is recognized for its distinct characteristics, one of which is its sweet odor. This gas is often used in medical settings, particularly in anesthesiology and dental practices, for its analgesic and anesthetic properties. The sweet smell can make it more tolerable for patients during procedures, distinguishing it from other medical gases that have little to no odor or might even be unpleasant to inhale.

In contrast, helium is inert and odorless, nitrogen is a colorless and odorless gas as well, and carbon dioxide has a slightly acidic odor, particularly at higher concentrations. These differences in odor are crucial in identifying gases and ensuring their proper handling and application in medical environments.