Industrial Preparation of Chloroform

Introduction
Chloroform (CHCl3) is a colorless, heavy, volatile liquid with a sweet odor. It was widely used in the past as an anesthetic, but its use has been significantly reduced due to its harmful effects on the liver and nervous system. Chloroform is primarily prepared industrially by reacting acetone with calcium hypochlorite.

Preparation Process
The industrial preparation of chloroform involves the following steps:

1. Acetone Production: Acetone (CH3COCH3) is produced through the dehydrogenation of isopropyl alcohol. This reaction is typically carried out using metal-based catalysts, such as copper or zinc.

2. Chlorination: Acetone is then chlorinated using chlorine gas (Cl2), which leads to the formation of chloroacetone (CH3COCH2Cl). This reaction is an example of an electrophilic substitution reaction.

• CH3COCH3 + Cl2 → CH3COCH2Cl + HCl

3. Dehydrochlorination: In the next step, chloroacetone is treated with a strong base, typically sodium hydroxide (NaOH), to remove the hydrogen chloride (HCl) and form dichloromethane (CH2Cl2).

• CH3COCH2Cl + NaOH → CH2Cl2 + CH3COONa

4. Further Chlorination: Dichloromethane is then further chlorinated using chlorine gas to produce chloroform.

• CH2Cl2 + Cl2 → CHCl3 + HCl

5. Purification: The chloroform produced in the previous step is purified by distillation to remove impurities and obtain the final product.

Calcium Hypochlorite as an Intermediate
In the given options, calcium hypochlorite (Ca(ClO)2) is the correct choice. It is used as an intermediate in the industrial preparation of chloroform. Calcium hypochlorite is a strong oxidizing agent that readily reacts with acetone to form chloroacetone, which is then further processed to produce chloroform.

The use of calcium hypochlorite as an intermediate offers several advantages:

1. Availability: Calcium hypochlorite is readily available and can be easily synthesized from calcium hydroxide and chlorine gas.

2. Cost-Effectiveness: Calcium hypochlorite is relatively inexpensive compared to other alternatives, making it a cost-effective option for industrial processes.

3. Efficiency: Calcium hypochlorite efficiently converts acetone into chloroacetone, which is an essential intermediate in the production of chloroform.

4. Controlled Reaction: The reaction between calcium hypochlorite and acetone can be controlled by adjusting the reaction conditions, such as temperature and concentration, to optimize the conversion and yield of chloroform.

Therefore, option B,