A. Ammonium salts produce haze in atmosphere.
B. Ozone gets produced when atmospheric oxygen reacts with chlorine radicals.
C. Polychlorinated biphenyls act as cleansing solvents.
D. 'Blue baby' syndrome occurs due to the presence of excess of sulphate ions in water.
Choose the correct answer from the options given below :

Solution

Chemistry ma’am · 2 steps

Test each statement on its own: chlorine destroys ozone, and blue baby comes from nitrate, not sulphate.

1. Approach. Mark each statement true or false on its own. Then find the option that lists exactly the true ones.

   Statement	What actually happens	Verdict
   A. Ammonium salts cause haze	Ammonia reacts with acidic gases to form fine particles such as NH₄NO₃ and (NH₄)₂SO₄. These scatter light and appear as haze.	True
   B. Chlorine radicals make ozone	Cl• + O₃ → ClO• + O₂. Chlorine radicals destroy ozone. This is how the ozone hole forms.	False
   C. PCBs are cleansing solvents	Polychlorinated biphenyls are used as cleansing solvents. They are also a well-known organic water pollutant.	True
   D. Blue baby from excess sulphate	Blue baby syndrome (methemoglobinemia) comes from excess nitrate in drinking water. Excess sulphate causes a laxative effect.	False

2. So. Only A and C are correct, so the answer is (d).

The idea to keep. Learn the pollutant and its effect as a fixed pair: chlorine radicals destroy ozone, nitrate causes blue baby syndrome, sulphate causes a laxative effect, fluoride causes mottling of teeth.

Answer from the NTA final answer key. Solution by PrepWiser.