Why are alkanes considered to be saturated hydrocarbons?

Alkanes are considered to be saturated hydrocarbons because they contain only single bonds between carbon atoms.

Alkanes are a type of hydrocarbon, which means they are composed entirely of hydrogen and carbon atoms. The term 'saturated' in chemistry refers to the fact that a molecule has the maximum number of hydrogen atoms it can possibly hold, with no room for any more. This is due to the presence of only single bonds between the carbon atoms in the molecule. Each carbon atom in an alkane is bonded to as many hydrogen atoms as possible, making it 'saturated' with hydrogen.

The structure of alkanes is such that each carbon atom forms four bonds and each hydrogen atom forms one bond. In alkanes, all of these bonds are single bonds. This means that each carbon atom is bonded to either four hydrogen atoms (in the case of methane, the simplest alkane) or to other carbon atoms and the remaining bonds are to hydrogen atoms. This results in a molecule that is 'full' or 'saturated' with hydrogen atoms.

The concept of saturation is important in organic chemistry because it affects the chemical properties of the molecule. Saturated hydrocarbons, like alkanes, are generally less reactive than unsaturated hydrocarbons, which contain double or triple bonds. This is because breaking a single bond is easier than breaking a double or triple bond, so unsaturated hydrocarbons are more likely to participate in chemical reactions.

In summary, alkanes are considered to be saturated hydrocarbons because their structure, composed entirely of single bonds, allows them to hold the maximum number of hydrogen atoms possible. This saturation gives them their characteristic chemical properties, including their relative lack of reactivity compared to unsaturated hydrocarbons.