Question

The major constituent of biogas is . It burns in the presence of oxygen to form and water.

• A. methane
• B. ethane
• C. carbon dioxide
• D. ammonia

Answer 1

Answer: (A), (C)

The correct options are
A methane
C carbon dioxide

Biogas is formed by the anaerobic decomposition of plant and animal matter in a closed biogas plant. The major constituent of it is methane gas (about 50%-65%) but it has traces of other gases like ethane $C_2{H}_6)$, butane $\left(C_4{H}_{10}\right)$, etc.

Biogas undergoes complete combustion when burnt in the presence of air as shown below.

$C{H}_4\left(g\right)+2O_2\left(g\right)\to C{O}_2\left(g\right)+2H_{2}O\left(g\right)$