Given below are two statements:
Statement I: Special vortex weather conditions in the lower stratosphere above Antarctica in winter cause denitrification and lead to the conversion of inactive chlorine into active chlorine molecules.
Statement II: HCl and ClONO2​ are two important active chlorine compounds.
Choose the correct answer from the options given below:

Correct option is C

1. Statement I:
· Correct.
· During the Antarctic winter, special vortex weather conditions (polar stratospheric clouds) lead to denitrification, which removes nitrogen-containing compounds. This allows the conversion of inactive chlorine compounds, such as HCl and ClONO2​ ​, into active chlorine molecules like Cl2​ and ClO. These active chlorine compounds are responsible for ozone depletion when sunlight returns in spring.
2. Statement II:
· Incorrect.
· HCl and ClONO2​ are not active chlorine compounds. Instead, they are reservoir compounds that store chlorine in an inactive form. Active chlorine compounds include Cl2 ​ and ClO, which directly participate in ozone depletion.
Thus, the correct answer is (c) Statement I is correct, but Statement II is incorrect.
Information Booster: 1. Key Processes in Ozone Depletion:
· Denitrification: Removal of nitrogen oxides (NOx) due to polar stratospheric clouds.
· Activation of Chlorine: Conversion of inactive chlorine compounds (HCl, ClONO2​) into active forms (Cl2​, ClO) under polar vortex conditions.
2. Active vs. Inactive Chlorine Compounds:
· Active: Cl2​, ClO (destroy ozone).
· Inactive (reservoir): HCl, ClONO2​ (do not directly harm ozone).
3. Role of Polar Vortex:
· Isolates the Antarctic stratosphere, creating extremely low temperatures for polar stratospheric cloud formation.
Additional Knowledge: Statement I (Correct):
· Explains the role of polar vortex and denitrification in chlorine activation, which drives ozone depletion in the Antarctic region.
Statement II (Incorrect):
· HCl and ClONO2​ are chemically stable reservoir species, not active participants in the catalytic destruction of ozone.