Question

Which of the following compound reacts with chlorobenzene to produce DDT? (a) trichloroacetaldehyde (b) m-chloroacetaldehyde (c) acetaldehyde (d) nitrobenzene

Short answer

(a) trichloroacetaldehyde

Step-by-step solution

Identify the reaction for DDT

To solve this, first recognize that DDT, or Dichloro-Diphenyl-Trichloroethane, is synthesized through the reaction of chloral (trichloroacetaldehyde) with chlorobenzene in the presence of sulfuric acid.

Review the given options

Analyze the list provided: (a) trichloroacetaldehyde, (b) m-chloroacetaldehyde, (c) acetaldehyde, and (d) nitrobenzene. Identify which is trichloroacetaldehyde, as it is the chemical required to synthesize DDT with chlorobenzene.

Select the correct option

The required compound for the reaction that produces DDT is trichloroacetaldehyde. Identify the option that matches this compound by checking against the choices provided.

Verify the chosen answer

Confirm that option (a) corresponds to trichloroacetaldehyde, the correct reactant to produce DDT from chlorobenzene, ensuring a match with the known DDT synthesis process.

Key concepts

Chlorobenzene

Chlorobenzene is an essential chemical compound in organic chemistry, participating in a wide array of reactions. With the formula \(C_6H_5Cl\), chlorobenzene is a colorless liquid with an almond-like odor. It plays a crucial role in the production of various chemicals, including DDT. Besides, it is a commonly used solvent and a precursor in the synthesis of other compounds.

Chlorobenzene is categorized as an aromatic chlorinated hydrocarbon, highlighting its presence in benzene derivatives.

• It is less reactive than aliphatic chlorides due to the stability imparted by the aromatic ring.
• The halogen (chlorine atom) is bonded directly to the benzene ring.
• This structure influences how it reacts with other chemicals, particularly in the production of more complex molecules like DDT.

To transform chlorobenzene into more intricate compounds, specific conditions, such as the presence of catalytic acids like sulfuric acid, are required.

Its industrial significance spans various applications, from the creation of herbicides and dyes to synthetic rubber production. Understanding chlorobenzene is key for students studying organic chemistry, due to its multifaceted applications and its role in classical synthesis reactions.

Trichloroacetaldehyde

Trichloroacetaldehyde, also known as chloral, is a pivotal compound in organic synthesis. With the molecular formula \(C_2HCl_3O\), it is known for its reactivity, especially in the formation of DDT.

Trichloroacetaldehyde, like chlorobenzene, has specific properties that make it suitable for chemical synthesis.

• It is a colorless to yellowish liquid under normal conditions.
• The presence of three chlorine atoms contributes to its high electron-withdrawing capability.
• This attribute makes it highly reactive with benzene derivatives like chlorobenzene, especially when a catalyst such as sulfuric acid is present.

In the reaction to produce DDT, trichloroacetaldehyde undergoes electrophilic aromatic substitution, where the chlorine atoms facilitate the reaction by stabilizing intermediates.

Understanding the function of trichloroacetaldehyde in reactions unveils its broader use in producing various synthetic chemicals, particularly due to its capacity to introduce chlorine efficiently into organic molecules.

Organic Chemistry Reactions

Organic chemistry reactions form the backbone of creating complex organic compounds like DDT. These reactions often involve the transformation of simple molecules into more complex structures through a series of well-defined steps.

In the context of DDT synthesis, the reaction proceeds through a pathway called electrophilic aromatic substitution.

• Here, the aromatic compound chlorobenzene serves as a substrate that reacts with an electrophile, in this case, trichloroacetaldehyde.
• This occurs in the presence of an acid catalyst such as sulfuric acid, which helps facilitate the reaction by generating more reactive intermediates.
• The interaction leads to the replacement of a hydrogen atom in the benzene ring with a trichloromethyl group, forming DDT.

This type of reaction not only underscores the versatility of chlorobenzene as a reactant but also highlights the transformative capability of trichloroacetaldehyde.

By mastering organic chemistry reactions, students gain insight into how small changes in molecular structure create substantial differences in chemical properties. This knowledge is fundamental for the synthesis of pharmaceuticals, agriculture chemicals, and materials.