Question

Why are single bonds saturated?

Answer 1

Single bonds themselves are not saturated, but an organic molecule composed of only single bonds is said to be saturated.

Explanation:

An organic molecule composed of carbon atoms linked by single bonds is said to be saturated. For example, hexane, decane, octadecane are all alkanes and are all saturated.

Organic molecules with carbon-carbon double or triple bonds are said to be unsaturated. For example, 1-hexene, 1,3-decadiene, or 7-octadecyne.

Think of unsaturation as the ability of an organic molecule to add hydrogen to its backbone. Every double bond can add one molecule of hydrogen and every triple bond can add two molecules of hydrogen. A molecule with only single bonds cannot add any more hydrogen and is thus saturated with hydrogen.