Easiest Adehydes. ketons and Carboxylic Acids Notes12th class Cbse

detailed note on the chapter "Aldehydes, Ketones and Carboxylic Acids" in Class 12 Chemistry:

 

Introduction:

Aldehydes, ketones, and carboxylic acids are three important classes of organic compounds that contain a carbonyl functional group (-C=O). Aldehydes have the carbonyl group at the end of a carbon chain, while ketones have the carbonyl group in the middle of a carbon chain. Carboxylic acids have a carbonyl group and a hydroxyl group (-OH) attached to the same carbon atom.

Preparation of Aldehydes and Ketones:

Aldehydes and ketones can be prepared by the oxidation of alcohols. Primary alcohols are oxidized to aldehydes, while secondary alcohols are oxidized to ketones. Aldehydes and ketones can also be prepared by the oxidation of alkylbenzenes with potassium permanganate or chromyl chloride.

Preparation of Carboxylic Acids:

Carboxylic acids can be prepared by the oxidation of primary alcohols or aldehydes with potassium permanganate or chromic acid. Carboxylic acids can also be prepared by the hydrolysis of nitriles, which are organic compounds containing a cyano functional group (-CN).

Physical Properties:

Aldehydes, ketones, and carboxylic acids have lower boiling points than alcohols and carboxylic acids of similar molecular weight. This is because they cannot form hydrogen bonds with themselves, but can form hydrogen bonds with water molecules.

Chemical Properties:

Aldehydes and ketones undergo nucleophilic addition reactions with nucleophiles such as water, alcohols, and ammonia. Carboxylic acids undergo nucleophilic substitution reactions with nucleophiles such as water and alcohols. Aldehydes and ketones can be reduced to alcohols using reducing agents such as sodium borohydride or lithium aluminum hydride. Carboxylic acids can be reduced to alcohols using reducing agents such as lithium aluminum hydride.

Acidity of Carboxylic Acids:

Carboxylic acids are weak acids that dissociate partially in water to form carboxylate ions and hydronium ions. The acidity of carboxylic acids is due to the ability of the carboxyl group to donate a proton to a base. The strength of carboxylic acids as acids increases with the number of electron-withdrawing groups attached to the carbonyl group.

In conclusion, the chapter "Aldehydes, Ketones and Carboxylic Acids" in Class 12 Chemistry covers important concepts related to the preparation, physical and chemical properties, and acidity of aldehydes, ketones, and carboxylic acids.