Hydrocarbons

Classification of Hydrocarbons

Hydrocarbons are divided into aliphatic (open-chain) and aromatic (closed-ring with delocalized pi electrons) compounds. Aliphatic hydrocarbons are further categorized into saturated alkanes and unsaturated alkenes and alkynes.

Conformations of Alkanes

Alkanes exhibit different spatial arrangements called conformations due to free rotation around carbon-carbon single bonds. Staggered and eclipsed conformations are the most common, with staggered being more stable due to minimal torsional strain.

Markovnikov's Rule

During the addition of an unsymmetrical reagent (like HBr) to an unsymmetrical alkene, the negative part of the adding molecule attaches itself to the carbon atom possessing lesser number of hydrogen atoms.

Aromaticity and Huckel's Rule

Aromatic compounds are cyclic, planar systems that follow Huckel's Rule of $(4n + 2)$ $\pi$ electrons, where $n$ is an integer ($0, 1, 2, \dots$), providing exceptional stability known as resonance energy.

Directive Influence of Functional Groups in Benzene

Substituents already present on a benzene ring dictate the position of incoming electrophiles. Ortho/para-directing groups activate the ring, while meta-directing groups deactivate it.