Aldehydes and ketones are commonly prepared by the oxidation of primary and secondary alcohols, respectively.

Carbonyl compounds have a planar structure with a π-bond, leading to substantial dipole moments. The high polarity is explained by resonance, involving neutral (A) and dipolar (B) structures, contributing to the overall dipole moment of carbonyl compounds.

The double bond is polarized due to the higher electronegativity of oxygen. The carbonyl carbon acts as an electrophilic (Lewis acid), and the carbonyl oxygen serves as a nucleophilic (Lewis base) center.

Nucleophilic addition involves attack by a nucleophile on the electrophilic carbon of the carbonyl group, changing the hybridization of the carbonyl carbon from sp² to sp³. This process forms a tetrahedral alkoxide intermediate that captures a proton to yield the ...

Aldehydes and ketones undergo nucleophilic addition reactions, whereas alkenes experience electrophilic addition reactions.

Lower aldehydes and ketones (e.g., methanal, ethanal, propanone) are miscible with water due to hydrogen bonding. However, solubility decreases with increasing alkyl chain length.

The absence of intermolecular hydrogen bonding in aldehydes and ketones contributes to their lower boiling points compared to alcohols. Alcohols exhibit stronger intermolecular forces due to hydrogen bonding.

Boiling points of aldehydes and ketones are higher than hydrocarbons and ethers due to dipole-dipole interactions. Weak molecular association in aldehydes and ketones results in these higher boiling points.

Ozonolysis of alkenes followed by reaction with zinc dust and water yields aldehydes, ketones, or a mixture. Hydration of ethyne in the presence of H₂SO₄ and HgSO₄ produces acetaldehyde, while other alkynes yield ketones in this reaction.

Dehydrogenation of alcohols, particularly volatile ones, involves passing alcohol vapors over heavy metal catalysts like Ag or Cu to obtain aldehydes and ketones from primary and secondary alcohols, respectively.