Q.11 Match List-I with List-II
| List-I | List-II |
|---|---|
| (Pollutant) | (Characteristics) |
| (A) Sulphur dioxide | (I) Colourless gas with an offensive ‘rotten egg’ odor, slightly water soluble |
| (B) Nitrogen dioxide | (II) Colourless, heavy, water soluble gas, with a pungent odor |
| (C) Ozone | (III) Reddish-brown gas, slightly water soluble |
| (D) Hydrogen sulphide | (IV) Pale-blue gas, water soluble, unstable, sweetish odor |
Choose the correct answer from the options given below:
- (A) – (I), (B) – (II), (C) – (III), (D) – (IV)
- (A) – (I), (B) – (III), (C) – (II), (D) – (IV)
- (A) – (II), (B) – (III), (C) – (IV), (D) – (I)
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Option 1: (A)–(I), (B)–(II), (C)–(III), (D)–(IV) Incorrect—misassigns SO₂ (pungent, soluble) to rotten egg odor and H₂S (rotten egg) to pale-blue gas.
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Option 2: (A)–(I), (B)–(III), (C)–(II), (D)–(IV) Incorrect—wrongly links SO₂ to H₂S’s odor and ozone (pale-blue) to heavy colorless gas.
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Option 3: (A)–(II), (B)–(III), (C)–(IV), (D)–(I) Correct—Sulphur dioxide: colorless, heavy, water-soluble, pungent (II); Nitrogen dioxide: reddish-brown, slightly soluble (III); Ozone: pale-blue, water-soluble, unstable, sweetish (IV); Hydrogen sulphide: colorless, offensive rotten egg, slightly soluble (I).
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Option 4: (A)–(III), (B)–(IV), (C)–(I), (D)–(II) Incorrect—confuses SO₂ (not reddish-brown) with NO₂ and ozone with rotten egg odor.(A) – (III), (B) – (IV), (C) – (I), (D) – (II)
The correct matching for this pollutant characteristics question is option 3: (A) – (II), (B) – (III), (C) – (IV), (D) – (I).
Question Breakdown
This matching question from exams like GATE Life Sciences tests physical and chemical properties of key air pollutants, focusing on color, odor, solubility, and stability.
Introduction to Pollutant Matching List-I List-II
Pollutant matching List-I List-II links air pollutants like Sulphur dioxide, Nitrogen dioxide, Ozone, and Hydrogen sulphide to characteristics such as color, odor, and solubility—crucial for GATE Life Sciences environmental science PYQs. These properties determine their reactivity, health impacts, and monitoring methods.
Sulphur Dioxide Characteristics
Sulphur dioxide (A) is a colorless, heavy, water-soluble gas with pungent odor (II), formed from fossil fuel combustion; it causes acid rain and respiratory irritation via SO₂ + H₂O → H₂SO₃.
Nitrogen Dioxide Properties
Nitrogen dioxide (B) appears as a reddish-brown gas, slightly water-soluble (III), from vehicle exhaust and industry; it contributes to smog (NO₂ → NO + O) and photochemical reactions.
Ozone Physical Traits
Ozone (C) is a pale-blue, water-soluble, unstable gas with sweetish odor (IV), a tropospheric pollutant from VOC-NOx reactions under sunlight; highly reactive, causing lung damage.
Hydrogen Sulphide Features
Hydrogen sulphide (D) is colorless with offensive rotten egg odor, slightly water-soluble (I), from decay and industry; toxic at low levels, inhibiting cytochrome oxidase.
Pollutant (List-I) Characteristics (List-II) Color/Odor Solubility/Stability (A) Sulphur dioxide (II) Colorless, heavy, pungent None/pungent High water-soluble (B) Nitrogen dioxide (III) Reddish-brown Red-brown/none Slightly soluble (C) Ozone (IV) Pale-blue, unstable, sweetish Pale-blue/sweet Water-soluble (D) Hydrogen sulphide (I) Colorless, rotten egg None/rotten egg Slightly soluble -
