• question_answer 70)   For dry cleaning, in the place of tetrachloroethene, liquefied carbon dioxide with suitable detergent in an alternative solvent. What type of harm to the environment will be prevented by stopping use of tetrachloroethene? Will use of liquefied carbon dioxide with detergent be completely safe from the point of view of pollution? Explain.

Solvents used to dry clean clothes are usually chlorinated compounds such as tetra chloroethylene $(CC{{l}_{2}}=CC{{l}_{2}})$which is a potential human carcinogen. These chlorinated compounds also have serious environmental consequences such as greenhouse effect, ozone depletion, water pollution, etc. The use of liquefied carbon dioxide with a suitable detergent for dry cleaning will not be completely safe from the point of view of pollution but will be less harmful.