In the given diagram, the gas X can be:
| 1. | Hydrogen sulfide | 2. | Carbon monoxide |
| 3. | Ammonia | 4. | Oxygen |
Methanogens do not produce:
| 1. | oxygen | 2. | methane |
| 3. | hydrogen sulfide | 4. | carbon dioxide |
Biogas is a mixture of:
| 1. | Methane, Carbon dioxide, and Hydrogen sulfide |
| 2. | Methane, Carbon dioxide, and Ammonia |
| 3. | Methane, Ammonia, and Hydrogen sulfide |
| 4. | Ammonia, Carbon dioxide, and Hydrogen sulfide |