Very Short Question and Answers - Saturated and Unsaturated Hydrocarbons

Hydrocarbons are compounds made up of only hydrogen and carbon atoms.

They are classified as saturated hydrocarbons (single bonds only) and unsaturated hydrocarbons (at least one double or triple bond).

The general formula for alkanes is CₙH₂ₙ₊₂.

Only single covalent bonds are present between carbon atoms.

Methane (CH₄) and ethane (C₂H₆) are examples of saturated hydrocarbons.

Because each carbon atom is bonded to as many hydrogen atoms as possible.

The general formula for alkenes is CₙH₂ₙ.

Ethene (C₂H₄) and propene (C₃H₆) are examples of alkenes.

The general formula for alkynes is CₙH₂ₙ₋₂.

Ethyne (C₂H₂), also known as acetylene, is an example of an alkyne.

They usually undergo substitution reactions.

They usually undergo addition reactions.

Because the double or triple bonds can easily open up to accept more atoms.

   H   H
   |   |
 H–C = C–H
   |   |
   H   H

If the hydrogen count fits CₙH₂ₙ (alkenes) or CₙH₂ₙ₋₂ (alkynes), it's unsaturated; also, look for fewer hydrogens than in alkanes (CₙH₂ₙ₊₂).

Ethyne is mainly used in oxy-acetylene torches for welding.

Ethane (C₂H₆) has more hydrogen atoms than ethene (C₂H₄) because it is saturated and has only single bonds.

Alkynes have at least one triple bond (C≡C) between carbon atoms.

Unsaturated hydrocarbons like ethene (C₂H₄) have double bonds that can open up, allowing them to join into long chains or polymers.

Saturated hydrocarbons contain only single bonds between carbon atoms, while unsaturated hydrocarbons have at least one double or triple bond.