Which statement correctly describes bonding in saturated vs unsaturated hydrocarbons?

Which statement correctly describes bonding in saturated vs unsaturated hydrocarbons?

• A. Saturated hydrocarbons contain only C-C single bonds; unsaturated hydrocarbons contain at least one C=C double bond.
• B. Saturated hydrocarbons contain C=C bonds.
• C. Alkanes have triple bonds.
• D. Alkenes have only C-C single bonds.

Answer: (A)

Saturation is about how many hydrogens fit around the carbon skeleton given the bonds between carbons. Hydrocarbons with only C–C single bonds can stack in the most hydrogens, so they are saturated. If there is any C=C double bond (or even a C≡C triple bond), that carbon–carbon bond uses up bonding capacity and reduces the number of hydrogens, making the molecule unsaturated. So the correct statement says saturated hydrocarbons have only C–C single bonds, and unsaturated hydrocarbons contain at least one C=C double bond. The other ideas clash with this pattern: alkanes don’t have triple bonds, and alkenes don’t have only single bonds.

Saturation is about how many hydrogens fit around the carbon skeleton given the bonds between carbons. Hydrocarbons with only C–C single bonds can stack in the most hydrogens, so they are saturated. If there is any C=C double bond (or even a C≡C triple bond), that carbon–carbon bond uses up bonding capacity and reduces the number of hydrogens, making the molecule unsaturated. So the correct statement says saturated hydrocarbons have only C–C single bonds, and unsaturated hydrocarbons contain at least one C=C double bond. The other ideas clash with this pattern: alkanes don’t have triple bonds, and alkenes don’t have only single bonds.