Match List - I with List - II. List - I; List - II (a) 2SO2(g) + O2(g) → 2SO3(g); (i) Acid rain (b) HOCl(g) →(hν) OH + Cl; (ii) Smog (c) CaCO3 + H2SO4 → CaSO4 + H2O + CO2; (iii) Ozone depletion (d) NO2(g) →(hν) NO(g) + O(g); (iv) Tropospheric pollution Choose the correct answer from the options given below.

NEET UG 2021 · Chemistry · Question 86

NEET 2021 Chemistry, question 86

Question 86 of the NEET 2021 paper (code O1) is a Chemistry question from Environmental Chemistry. Its idea, Tropospheric and Stratospheric Reactions, was asked only this once in NEET 2017–2026. The NTA final answer key gives option 1.

Updated 2026-10-08

Q86 · Chemistry

\mathrm{2SO_2(g) + O_2(g) \to 2SO_3(g)}

List - I	List - II
(a) $\mathrm{2SO_2(g) + O_2(g) \to 2SO_3(g)}$	(i) Acid rain
(b) $\mathrm{HOCl(g) \xrightarrow{h\nu} \dot{O}H + \dot{C}l}$	(ii) Smog
(c) $\mathrm{CaCO_3 + H_2SO_4 \to CaSO_4 + H_2O + CO_2}$	(iii) Ozone depletion
(d) $\mathrm{NO_2(g) \xrightarrow{h\nu} NO(g) + O(g)}$	(iv) Tropospheric pollution

1 (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii) Official answer 2 (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i) 3 (a)-(i), (b)-(ii), (c)-(iii), (d)-(iv) 4 (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)

Official answer: option 1 · NTA final answer key

Same idea

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No other NEET paper from 2017–2026 tested this exact idea.

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The chapter

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6 questions from 2017–2026, asked in 6 of 10 papers, about 0.6 a paper. Environmental Chemistry alone had 6.

Chapter analysis

The only question on Tropospheric and Stratospheric Reactions

Environmental Chemistry in ten years of NEET

Environmental Chemistry: questions per paper