Question

Column-I Column-II (Reactions) (P) Picric acid is obtained on nitration (Q) TNT explosive is obtained on nitration (R) BHC insecticide is obtained on chlorination in sunlight (S) Schiff's base is obtained on reaction with \(\mathrm{Ph}-\mathrm{NH}_{2}\)

Short answer

(P): Picric acid, (Q): TNT explosive, (R): BHC insecticide, (S): Schiff's base

Step-by-step solution

Picric Acid Chemical Reaction

Picric acid is formed when phenol undergoes nitration. This process involves introducing a nitro group (-NO2). Here we are looking for strong nitration conditions in the given options. In this case, option (P) refers to the formation of picric acid by nitration, so we can match it with picric acid.

TNT Chemical Reaction

TNT (Trinitrotoluene) is a highly explosive compound. It's formed when toluene undergoes nitration. In this case, option (Q) describes the nitration of toluene, which will produce TNT, so we can match it with TNT explosive.

BHC Insecticide Chemical Reaction

BHC (Benzene Hexachloride) is an insecticide produced by chlorination of benzene. In this case, option (R) states that BHC is obtained by benzene chlorination in sunlight. So, we can match it with BHC insecticide.

Schiff's Base Chemical Reaction

Schiff's base is formed when an aldehyde or ketone reacts with a primary amine, leading to the formation of an imine. Here, the option (S) involves the reaction of a compound with (Ph-NH2), which is a primary amine. So, we can match it with Schiff's base. In conclusion: - (P) Picric acid is obtained on nitration: Picric acid - (Q) TNT explosive is obtained on nitration: TNT explosive - (R) BHC insecticide is obtained on chlorination in sunlight: BHC insecticide - (S) Schiff's base is obtained on reaction with \(\mathrm{Ph}-\mathrm{NH}_{2}\): Schiff's base

Key concepts

Nitration

Nitration is a chemical process in which a nitro group ( O_2 ) is introduced into an organic compound. This reaction is particularly notable in the creation of compounds like picric acid and trinitrotoluene (TNT). The nitration process typically requires a mix of nitric acid and sulfuric acid, which helps to produce the nitronium ion ( O_2^+ ), the active species in the reaction.

• Picric Acid: Picric acid, also known as 2,4,6-trinitrophenol, is formed when phenol reacts with concentrated nitric acid under controlled conditions. It's primarily used in dyes and as an explosive.
• TNT: Formed from the nitration of toluene, TNT is a well-known explosive. The nitration is a stepwise process involving three nitro groups being introduced to the toluene ring, resulting in the formation of trinitrotoluene.

Each of these compounds highlights the utility of nitration in creating both industrially valuable chemicals and explosive materials.

Chlorination

Chlorination is a method of introducing chlorine atoms into a molecule. In organic chemistry, chlorination can transform simple hydrocarbons into valuable chemicals. One key example is the production of Benzene Hexachloride (BHC), commonly used as an insecticide.

• Process: Chlorination typically involves substituting hydrogen atoms in a hydrocarbon with chlorine atoms. The reaction can be initiated using sunlight or heat to generate chlorine radicals.
• Example - BHC Production: BHC is obtained when benzene undergoes chlorination in the presence of sunlight. The energy from sunlight facilitates the radical process, leading to the addition of chlorine atoms to benzene, forming several isomers of hexachlorocyclohexane.

Chlorination serves an essential role in producing various chemical products used in agriculture and other industries.

Schiff's Base Formation

Schiff's base formation is a fundamental organic reaction where an amine reacts with an aldehyde or a ketone to form an imine. The process involves the nucleophilic attack of a primary amine on the carbonyl carbon of the aldehyde or ketone.

• Mechanism: The process begins with the nucleophilic addition of the amine ( H_2RN ) to the carbonyl group ( RC(=O)R' ), followed by dehydration to form the imine ( RCH=NR' ).
• Applications: Schiff bases are crucial intermediates in the synthesis of various organic compounds, and they can function as ligands in coordination chemistry. In food chemistry, they are important for generating flavors and fragrances.

The flexibility and functionality of imines make Schiff's bases valuable in a wide range of chemical syntheses.

Organic Synthesis

Organic synthesis refers to constructing complex organic molecules from simpler ones through a series of well-planned chemical reactions. It's a crucial aspect of chemistry with applications in pharmaceuticals, agriculture, and material science.

• Importance: It allows chemists to create new compounds with specific properties, contributing to advancements in drug development, crop protection, and production of new materials.
• Methods: Organic synthesis often involves reactions like nitration, chlorination, and the formation of Schiff bases to introduce new functional groups and build carbon skeletons.

Overall, organic synthesis is about creativity and precision, enabling scientists to innovate and solve real-world challenges through chemistry.