Which gas is commonly produced as an end product of decomposition and has a foul odor?

Which gas is commonly produced as an end product of decomposition and has a foul odor?

• A. Hydrogen sulfide
• B. Water
• C. Carbon dioxide
• D. Methane

Answer: (A)

Foul odors from decomposition come from sulfur compounds broken down by bacteria. Hydrogen sulfide is the gas responsible for that distinctive rotten-egg smell. It forms in anaerobic environments where sulfur-containing amino acids or sulfates are reduced by microbes. Other common decomposition gases, like water vapor, carbon dioxide, and methane, are odorless, so they don’t produce that recognizable stink. That combination of being produced during decay and having a strong rotten-egg odor makes hydrogen sulfide the gas described.

Foul odors from decomposition come from sulfur compounds broken down by bacteria. Hydrogen sulfide is the gas responsible for that distinctive rotten-egg smell. It forms in anaerobic environments where sulfur-containing amino acids or sulfates are reduced by microbes. Other common decomposition gases, like water vapor, carbon dioxide, and methane, are odorless, so they don’t produce that recognizable stink. That combination of being produced during decay and having a strong rotten-egg odor makes hydrogen sulfide the gas described.