JEE Main 20 July 2021 Shift 1 Solved Paper

Chlorine gas was used earlier for bleaching paper. These days, hydrogen peroxide (H2O2) with suitable catalyst.
Tetra chlroroethene (Cl2C=CCl2) was earlier used as solvent for dry cleaning. The compound contaminates the ground water and is also a suspected carcinogen. Replacement of halogenated solvent by liquid CO2 will result in less harm to groundwater.
Hence given statement (4) is correct.