Which bacterium is responsible for converting ammonia into nitrites in the nitrogen cycle? MCQ with Answer and Explanation

Explanation:
Sulphuric acid (H₂SO₄) is historically called oil of vitriol because it was prepared by distilling green vitriol (ferrous sulfate heptahydrate). It is a dense, oily liquid. Nitric acid is aqua fortis, hydrochloric acid was called muriatic acid or spirit of salt. Sulphuric acid is the king of chemicals due to its widespread use in industries like fertilizer, petroleum refining, and chemical synthesis.

Explanation:
Biogas is produced by anaerobic decomposition of organic matter (cow dung, agricultural waste) and typically contains 50-70% methane (CH₄), 30-40% CO₂, and traces of H₂S, NH₃, and H₂. Methane provides the fuel value. Biogas is a renewable fuel used for cooking and electricity generation. The slurry is good manure.

Explanation:
Teflon (PTFE) has a very low coefficient of friction and surface energy because the fluorine atoms form a protective shield around the carbon backbone, making it difficult for other substances to adhere. This is not due to polarity (C-F bonds are polar but the molecule overall is non-polar due to symmetry). It is extremely inert, resisting most chemicals.