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

Explanation

(i) Tetrachloroethene `(Cl_2C=C Cl_2)` is suspected to be carcinogenic and contaminates the ground water This harmful effect will be prevented by using liquefied `CO_2` along with suitable detergent.
(ii) Use of liquefied `CO_2` along with detergent will not be completely safe because detergents also cause pollution as most of the detergents are non-biodegradable Also, liquefied `CO_2` will ultimately enter into the atmosphere and contribute to the greenhouse effect