Organic Chemistry - Fundamentals of organic chemistry

A homologous series is a group of organic compounds that share the same general formula, have similar chemical properties, and show a gradual change in physical properties. Each member differs from the next by a $CH_2$ unit.

Physical properties like boiling point increase with the number of carbon atoms due to the increase in London dispersion forces as the molar mass and electron cloud size increase.

Structural isomers are compounds with the same molecular formula but different structural arrangements. This includes chain isomerism, positional isomerism, and functional group isomerism.

IUPAC Nomenclature involves identifying the longest carbon chain (stem), the primary functional group (suffix), and any substituents (prefix). For example, a 4-carbon chain with an alcohol group on the second carbon is named $butan-2-ol$.

Carbon atoms and their attached functional groups (like alcohols or halogenoalkanes) are classified as primary ($1^\circ$), secondary ($2^\circ$), or tertiary ($3^\circ$) based on how many other carbon atoms are bonded to the carbon atom containing the functional group.

The Index of Hydrogen Deficiency (IHD), or degree of unsaturation, indicates the number of rings and/or $\pi$ bonds in a molecule.

Benzene ($C_6H_6$) has a unique structure consisting of a planar hexagonal ring with a delocalized $\pi$ system. This delocalization provides extra stability, making benzene undergo substitution reactions rather than addition reactions.

Functional groups to identify: Alkanes ($-C-C-$), Alkenes ($-C=C-$), Alkynes ($-C\equiv C-$), Alcohols ($-OH$), Ethers ($-O-$), Aldehydes ($-CHO$), Ketones ($-CO-$), Carboxylic Acids ($-COOH$), Esters ($-COO-$), Amines ($-NH_2$), Amides ($-CONH_2$), and Nitriles ($-CN$).