Description:-
Chloroform is a colorless, volatile, liquid derivative of trichloroethane with an ether-like odor. Formerly used as an inhaled anesthetic during surgery, the primary use of chloroform today is in industry, where it is used as a solvent and in the production of the refrigerant Freon. Acute chloroform toxicity results in impaired liver function, cardiac arrhythmia, nausea and central nervous system dysfunction. As a byproduct of water chlorination, chloroform may be present in small amounts in chlorinated water. (NCI04)
Reaction:-
Step-1: At first bleaching powder and water (1:2) react to form chlorine and lime water [Ca(OH)2]
Ca(OCL) + H2O → Cl2 + Ca(OH)2
Step-2: (Oxidation): In this step, ethanol is oxidized by chlorine or bleaching powder to form ethyl aldehyde.
CH3 -CH2–OH + Cl2 → CH3 –CHO + 2HCl
Step-3 (Chlorination): The produced ethyl aldehyde reacts with chlorine to produce chloral.
CH3 –CHO + 3Cl2 → Cl3C –CHO + 3HCl
Step-4 (Hydrolysis): In this step, the produced chloral undergoes hydrolysis with Ca(OH)2 with the formation of chloroform and calcium format.
Cl3 - C – CHO + Ca(OH)2 → 2CHCl3 + (COO)2Ca
Procedure :–
In the surrounding bottom flask, bleaching powder paste is arranged by adding 100g of bleaching powder to 200 ml of water and crushing the residue of bleaching powder in a mortar with the help of a pestle.
After that, 25 ml of ethanol or acetone is added to it.
The flask is then fixed with a water condenser at the other end of which a receiver is joined.
The flask is then placed over a sand bath and heated till a mixture of chloroform and water distills over.
The mixture from the receiver is transferred to a separating funnel and the lower layer of chloroform is separated.
Properties of Trichloroethane:-
(i) In the presence of light and air, chloroform is slowly oxidized to highly toxic phosgene (carbonyl chloride),
2CHCl3+ O2+ Δ→ 2COCl2 (phosgene) + 2HCl
The absence of air and light is required to prevent the origin of phosgene. This is why chloroform is stored in a dark brown bottle in a dark brown bottle with a small amount (0.6-1%) of pure ethyl alcohol. Ethyl alcohol acts as an antioxidant to prevent the breakdown of chloroform. Even if a small amount of phosphine is produced, it reacts with alcohol to form toxic dimethyl carbonate.
(ii) It produces acetylene in reaction with silver powder.
Cl3CH + 6Ag + CHCl3 +Δ → CH=CH + 6AgCl
Uses of Trichloroethane:-
● Chloroform is used in industry as suitable solvent for oil, fat, rubber, resin, alkaloid (alkaline) iodine etc.
• It is currently the largest Freon product, called the freezer R-22.
Physiological effects:-
Chloroform was once used as an anesthetic. But later, the use of relatively less toxic and safe anesthetic ether began. Inhalation of chloroform vapor reduces the capacity of the central nervous system. Inhalation of air containing 900 percent chloroform vapor in a million breaths causes dizziness, fatigue, and dizziness.
Prolonged exposure to chloroform vapor can damage the liver and kidneys, and exposure to chloroform can cause skin lesions.
Product Description:-
Chloroform Chemical, 500 Ml, Packaging Type: Glass Bottle
₹ 300 / Kg
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