Question

Give uses of freon 12, DDT, carbon tetrachloride and iodoform.

Answer 1

Hint: Each compound has its particular use. Freon-12 is used as a refrigerant. DDT is an insecticide. Carbon tetrachloride is used in the manufacture of refrigerants and propellants. Earlier, iodoform was used as an antiseptic.

Complete answer:
> Uses of freon 12 (dichlorodifluoromethane):
In refrigerators and air conditioners, freon 12 is used as a refrigerant. Also, freon 12 finds applications in aerosol spray propellants such as body sprays and hair sprays.
Since, freon 12 damages ozone layers, it’s use should not be allowed.
> Uses of DDT (p,p-dichlorodiphenyltrichloroethane):
DDT is an insecticide and is effective against mosquitoes and lice. But it is banned in some countries due to its harmful effects.
> Uses of carbon tetrachloride:
Carbon tetrachloride is used in the manufacture of refrigerants and propellants for aerosol cans. In the industrial preparation of pharmaceuticals, carbon tetrachloride is used as a solvent. In the synthesis of chlorofluorocarbons and other chemicals carbon tetrachloride is used as feedstock.
Earlier (upto 1960’s), carbon tetrachloride was used as a cleansing fluid, a fire extinguisher and a degreasing agent.
> Uses of Iodoform:
When iodoform comes in contact with skin, it liberates free iodine. Hence, iodoform was used as an antiseptic. Nowadays, other formulations containing iodine are used in place of iodoform due to the objectionable smell of iodoform.
> Molecules of Freon 12, carbon tetrachloride and iodoform, mostly contain carbon and halogen as major elements. Whereas, molecules of DDT contain more number of carbon and hydrogen atoms than chlorine atoms.

Note: Many compounds that were widely used earlier, are now banned due to harmful effects. These are replaced nowadays with other compounds having better efficacy and fewer harmful side effects.