Question

Industrial preparation of chloroform employs acetone and

• A. phosgene
• B. calcium hypochlorite
• C. chlorine gas
• D. sodium chloride

Answer 1

The Correct Option is B

The industrial preparation of chloroform (CHCl₃) involves the reaction of acetone with a halogenating agent. In this process, calcium hypochlorite (Ca(ClO)₂) is used as the chlorinating agent. Here is the step-by-step explanation:

1. Conceptual Background: Chloroform production is based on the halogenation and hydrolysis of acetone. Chlorinating agents are used to introduce chlorine atoms into the organic compound.
2. Choice of Chlorinating Agent: Among the given options, calcium hypochlorite is a well-known chlorinating agent used in the industrial preparation of chloroform. It provides the necessary hypochlorite ions (ClO⁻) that help in the chlorination and subsequent generation of chloroform.
3. Reaction Mechanism: The acetone reacts with calcium hypochlorite, which supplies the necessary chlorine for converting acetone into chloroform:
   • Firstly, acetone reacts with calcium hypochlorite to form trichloroacetone.
   • Trichloroacetone undergoes hydrolysis in the basic medium to produce chloroform and other by-products.
   The reaction can be summarized as follows: \[ \text{CH}_3\text{COCH}_3 + 3\text{Ca(ClO)_2} \rightarrow \text{CHCl}_3 + \text{other products} \]
4. Correctness of the Option: Therefore, the correct option from the choices given for the production of chloroform is calcium hypochlorite.
5. Excluding Other Options:
   • Phosgene is a toxic gas used in the production of polycarbonate plastics and is not related to chloroform production from acetone.
   • Chlorine gas can be used in some organic syntheses but is not directly involved in the acetone-to-chloroform reaction.
   • Sodium chloride is a common salt and does not participate in chloroform preparation from acetone.

The decision to use calcium hypochlorite is due to its effectiveness in introducing chlorine into organic molecules like acetone to produce chloroform.