JEE Main · 2023 · 25 Jan 2023 · Shift 2 · Environmental Chemistry

Ammonium salts such as ammonium sulphate persist in air as fine particulate matter that scatters light, producing the haze seen in polluted atmospheres, so this statement holds. Atmospheric ozone is not generated by oxygen reacting with chlorine radicals; on the contrary chlorine radicals destroy ozone through ${\mathrm{Cl}}^{\bullet }+{\mathrm{O}}_3\to {\mathrm{ClO}}^{\bullet }+{\mathrm{O}}_2$, so that statement is wrong. Polychlorinated biphenyls, before their toxicity led to a ban, were indeed used as cleansing solvents and in industrial formulations, so this statement is correct. Blue baby syndrome arises from an excess of nitrate ions, not sulphate ions, in drinking water, so that statement is wrong. The valid statements are the ones on ammonium-salt haze and polychlorinated biphenyls, namely A and C only.