Question

Freon $12$ is prepared from:
A. $CC{l_4}$
B. $C{H_2}C{l_2}$
C. $CHC{l_3}$
D. $COC{l_2}$

Answer 1

Hint: Dichlorodifluoromethane (\[R - 12\] ) is a colorless gas which has the market name of Freon-12, and a chlorofluorocarbon halomethane (\[CFC\] ) used as a refrigerant and aerosol spray propellant. Complying with the Montreal Protocol, its manufacture was banned in developed countries (non-article 5 countries) in 1996, and developing countries in 2010 out of concerns about its damaging effect on the ozone layer.

Complete step by step answer:
Freon-12 is prepared by reacting carbon tetrachloride with hydrogen fluoride in the presence of a catalytic amount of antimony pentachloride. The reaction that takes place here is as follows:
$CC{l_4} + 2HF \to CC{l_2}{F_2} + 2HCl$
This reaction can also produce trichlorofluoromethane (\[CC{l_3}F\] ), chlorotrifluoromethane (\[CCl{F_3}\] ) and tetrafluoromethane (\[C{F_4}\] ). The chlorofluorocarbons produce a negative effect in the troposphere and affect very badly the ozone layer.$CFC$ are released in the atmosphere, and being light weighted, move upwards in the atmosphere and react with the ozone (${O_3}$ ) in the atmosphere. The chlorofluorocarbon in the presence of UV light coming from the sun breaks down under free radical mechanism and releases free halogen radicals which attack the ozone in the atmosphere. The ozone in reaction with such radicals, breaks down into oxygen gas and a free radical of oxygen.

The correct option is A. $CC{l_4}$ .

Note:
The only allowed use of Freon- 12 is that it is used as a fire retardant in submarines and aircraft. It is soluble in many organic solvents. Dichlorodifluoromethane was one of the original propellants for Silly String. \[R - 12\] cylinders are colored white. Freon-12 is used as an aerosol in the medicines. This gas is one of the major causes of ozone depletion and global warming.