Which one of the following gases is abundant in biogas?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Methane
Biogas is a mixture of gases produced by microbial activity, and it is used as a fuel. It is made by anaerobic bacteria called methanogens, such as Methanobacterium, which grow on cellulose-rich matter like cattle dung. The gas mixture is mainly methane, with some carbon dioxide and hydrogen.
(1) Hydrogen sulphide — Incorrect. It can be present in very small traces only.
(2) Carbon dioxide — Incorrect. Carbon dioxide is present, but in a smaller amount than methane.
(3) Oxygen — Incorrect. Biogas is made under anaerobic conditions, that is, without oxygen.
(4) Methane — Correct. Methanogens such as Methanobacterium produce a large amount of methane, along with CO2 and H2. So methane is the main (most abundant) gas of biogas.
NCERT Extract:
Microbes in Production of Biogas – …
