List the common products formed when an organic material containing the elements carbon, hydrogen, oxygen, sulfur, and nitrogen decomposes (a) under aerobic conditions, (b) under anaerobic conditions.

Aerobic decomposition is the process of breaking down organic material in the presence of oxygen. The primary microorganisms responsible for this decomposition process are bacteria and fungi. They metabolize organic compounds in the material and consume oxygen, releasing various products, including: 1. Carbon dioxide (CO2): Some carbon molecules in the decomposing material are converted into carbon dioxide during aerobic respiration. 2. Water (H2O): Hydrogen molecules combine with oxygen during the decomposition process to form water. 3. Heat: Energy is released during the oxidation process in the form of heat. 4. Inorganic nutrients like nitrates (NO3-) and sulfates (SO4^2-): Microorganisms break down nitrogen and sulfur-containing compounds, releasing nitrogen and sulfur in their oxidized forms. 5. Biomass: The microorganisms reproduce and increase their biomass, which becomes part of the decomposed material.

Anaerobic decomposition occurs in the absence of oxygen. The primary microorganisms responsible for anaerobic decomposition are methane-producing bacteria, known as methanogens, and sulfate-reducing bacteria. During this process, various products are formed, including: 1. Methane (CH4) and carbon dioxide (CO2): In the absence of oxygen, carbon molecules in the decomposing material are primarily converted into methane and carbon dioxide. 2. Water (H2O): Hydrogen molecules combine with other atoms during the anaerobic decomposition process to form water. 3. Hydrogen sulfide (H2S): Sulfate-reducing bacteria break down sulfur-containing compounds into hydrogen sulfide. 4. Ammonia (NH3): Nitrogen molecules are converted into ammonia during the anaerobic decomposition process. 5. Biomass: The microorganisms reproduce and increase their biomass, which becomes part of the decomposed material. 6. Acids and alcohols: Some organic acids (e.g., acetic acid) and alcohols (e.g., ethanol) are produced as intermediate products of anaerobic decomposition. In conclusion, the common products formed when organic materials containing carbon, hydrogen, oxygen, sulfur, and nitrogen decompose under aerobic conditions are CO2, H2O, heat, inorganic nutrients, and biomass. Under anaerobic conditions, the common products are CH4, CO2, H2O, H2S, NH3, biomass, organic acids, and alcohols.