What is the characteristic smell of pure propane?

Pure propane is actually odorless. This is a key characteristic of the gas, which is why an odorant is added during the refinement process to provide a detectable smell for safety reasons. The absence of any scent in pure propane makes it important to use odorants like ethyl mercaptan to help individuals identify leaks, as propane is highly flammable and can pose significant safety risks if not detected promptly.

The other options represent characteristics that may be associated with other gases or substances rather than pure propane. For example, a strong and pungent smell is typical of the odorants added to the gas, while fruity and chemically sweet scents do not correlate with propane itself.