Which gas can be characterized by its specific odor and is detected through chemical analysis?

The gas that can be characterized by its specific odor and is detected through chemical analysis is hydrogen sulfide (H2S). This colorless gas has a distinctive rotten egg smell, allowing it to be identified even at very low concentrations. Its detection is critical in various industries, particularly in mining and waste management, as hydrogen sulfide can be highly toxic and poses serious health risks.

While acetylene does have a slight odor, it is not as distinctly recognizable as the odor of hydrogen sulfide. Methane is essentially odorless; however, it may sometimes have an odorant added for safety reasons. Ethanol has a distinct alcoholic smell but does not have the same level of concern regarding toxicity and detection in the context of hazardous environments. Therefore, hydrogen sulfide is the gas that best fits the criteria of being characterized by its specific odor and detectable through chemical analysis.