Classification of Organic Compounds

Flashcards covering the lecture’s key points on the classification of organic compounds, including structural types, saturation, cyclicity, and representative examples.

What are the two broad structural classes of organic compounds?

Aliphatic compounds and aromatic compounds.

Which term describes open-chain organic compounds that contain only single C–C bonds?

Saturated aliphatic (acyclic) compounds.

Which structural feature makes an aliphatic compound unsaturated?

The presence of at least one C=C double bond or C≡C triple bond.

How do straight-chain and branched-chain hydrocarbons differ?

Straight-chain hydrocarbons have an uninterrupted carbon chain, whereas branched-chain hydrocarbons contain one or more side chains attached to the main chain.

Give an example of a straight-chain saturated hydrocarbon mentioned in the notes.

Butane (CH₃–CH₂–CH₂–CH₃).

Give an example of a branched-chain saturated hydrocarbon mentioned in the notes.

Isobutane / 2-methylpropane (CH₃–CH(CH₃)–CH₃).

What name is given to ring compounds composed solely of carbon atoms?

Homocyclic compounds.

What distinguishes a heterocyclic compound?

Its ring contains at least one heteroatom such as nitrogen, oxygen, or sulfur in addition to carbon.

Which molecule in the notes is a three-membered heterocycle containing oxygen?

Ethylene oxide (oxirane).

Identify one aromatic homocyclic compound listed in the notes.

Benzene.

Which aromatic heterocyclic compound is highlighted in the notes?

Pyridine.

Name the fused polycyclic aromatic compound shown alongside benzene in the notes.

Naphthalene.

Which term describes non-aromatic ring compounds such as cyclohexane?

Alicyclic compounds.

What is the key feature that differentiates alicyclic compounds from aromatic compounds?

Alicyclic rings lack the delocalized π-electron system characteristic of aromaticity.