What defines an alkane?

• A. A saturated hydrocarbon with double bonds
• B. A saturated hydrocarbon with triple bonds
• C. A saturated hydrocarbon with single bonds
• D. An unsaturated hydrocarbon with single bonds

Answer: (C)

An alkane is defined as a saturated hydrocarbon that contains only single bonds between carbon atoms. The term "saturated" indicates that these hydrocarbons have the maximum number of hydrogen atoms possible for the number of carbon atoms present, with no double or triple bonds contributing to the bonding.

For example, in a simple alkane like ethane (C2H6), each carbon atom is bonded to the maximum number of hydrogen atoms without involving any π (pi) bonding, which is characteristic of unsaturated hydrocarbons. This single-bond structure allows alkanes to be relatively stable and non-reactive compared to their unsaturated counterparts, which have higher reactivity due to the presence of double or triple bonds. Alkanes are also generally referred to as "paraffins" and are typically found in natural gas and petroleum products.

In contrast, the other options describe either unsaturated hydrocarbons or include bonding types that do not fit the criteria for alkanes.