Which of the following is incorrect regarding alkanes?

Options

A. (1) Natural gas and petroleum are the principal sources of alkanes.
B. (2) Some living organisms (called methanogens) produces methane from `CO_(2)` and `H_(2)`.
C. (3) On the earth, methane is the major component of natural gas.
D. (4) Alkanes are saturated cyclic hydrocarbons.

Answer

D

Explanation

Alkanes are saturated acyclic hydrocarbons with the general molecular formula `C_(n)H_(2n+2)`. Higher molecular mass alkanes are obtained largely by refining petroleum. Methanogens, very primitive creatures, may be the oldest organisms of the earth. They are found in ocean trenches, in mud, in sewage, and in cow's stomach.