Are alkanes saturated or unsaturated?

Are alkanes saturated or unsaturated?

• A. Saturated
• B. Unsaturated
• C. Aromatic
• D. Both saturated and unsaturated

Answer: (A)

Saturated means a molecule has the maximum possible hydrogens for its carbon framework, with only single bonds between carbon atoms. Alkanes fit this, since every carbon is bonded by single bonds to other carbons and to hydrogens, giving the general formula CnH2n+2. There are no carbon–carbon double or triple bonds, so they can’t have fewer hydrogens than this maximum. If a molecule had a C=C bond or a C≡C bond, or a ring with pi bonds, it would be unsaturated. Aromatic rings also involve pi bonds, so they aren’t saturated either. Therefore, alkanes are saturated.

Saturated means a molecule has the maximum possible hydrogens for its carbon framework, with only single bonds between carbon atoms. Alkanes fit this, since every carbon is bonded by single bonds to other carbons and to hydrogens, giving the general formula CnH2n+2. There are no carbon–carbon double or triple bonds, so they can’t have fewer hydrogens than this maximum. If a molecule had a C=C bond or a C≡C bond, or a ring with pi bonds, it would be unsaturated. Aromatic rings also involve pi bonds, so they aren’t saturated either. Therefore, alkanes are saturated.