Question

Match the List I and II and pick the correct matching from the codes given below.

List I	List II
i. Peroxyacetyl nitrate	1. Carcinogens
ii. Polycyclic aromatic hydrocarbons	2. Global warming
iii. IR active molecules	3. Photochemical smog
iv. Dioxins	4. Waste incineration

[A] (i)-3, (ii)-1, (iii)-4, (iv)-2
[B] (i)-3, (ii)-2, (iii)-4, (iv)-1
[C] (i)-3, (ii)-1, (iii)-2, (iv)-4
[D] (i)-4, (ii)-2, (iii)-1, (iv)-3

Answer 1

To answer this, firstly try to remember the meaning of the phenomena mentioned in the second list. Remember that PANs are photo-oxidants, PAHs are toxic and long term exposure causes cancer. You can use this to get the correct answer
Complete answer:
To answer this, let us briefly discuss the molecules and chemical compounds given in list I and the phenomena in list II and then try to inter-relate them.
Firstly, we will discuss the phenomenon mentioned in List II.
Carcinogens – A carcinogen is any substance, nuclei or radio-nuclei that is capable of promoting carcinogenesis that is the formation of cancer.
Global warming – The rise in temperature due to trapping of heat in the Earth’s atmosphere due to several gasses is known as global warming. Global warming is the major reason for melting of glacial ice, droughts, water shortage, increased risk of fire breakouts and many more.
Photochemical smog – It is basically a type of smog that is produced when the UV rays of the sun reacts with atmospheric nitrogen dioxide. It is more often during afternoon and mornings in hot cities because that’s when we receive the most sunlight.
Waste incineration – It is a treatment of waste where the waste is transformed into ashes, flue gas and heat by the combustion of certain organic substances contained in waste material. These ashes and heat produced can be further used as an energy source for various processes.
Now, let us discuss the List I.
Peroxyacetyl nitrate – It is the secondary pollutant present in photochemical smog. It is thermally unstable and breaks into peroxy ethanoyl radicals and nitrogen dioxide.
Polycyclic aromatic hydrocarbons – They are abbreviated as PAHs. It is a group of chemicals that we generally find in coal, gasoline and crude oil and are also produced when we burn tobacco, wood, garbage etc. Long term exposure to PAHs might cause cancer.
IR active molecules – We know that IR stands for Infrared region. The molecules that absorb infrared radiations are known as IR active molecules. The green-house gases are found to be IR active.
Dioxins – They are a class of highly toxic chemicals and they are produced by burning of chlorine based hydrocarbons.
From the above discussion we can compare the List I to List II as-

List I	List II
i. Peroxyacetyl nitrate	3. Photochemical smog
ii. Polycyclic aromatic hydrocarbons	1. Carcinogens
iii. IR active molecules	2. Global warming
iv. Dioxins	4. Waste incineration

Therefore, the correct answer is option [C] (i)-3, (ii)-1, (iii)-2, (iv)-4.

Note:
Peroxyacetilnitrates are abbreviated as PAN and it is a class of secondary pollutants. It is formed by the photochemical reaction of the hydrocarbons in it with atmospheric nitrogen dioxide.
Any molecule with two or three atoms is generally IR active. We know that a diatomic molecule with atoms of different electronegativity generates a dipole moment. This dipole moment absorbs radiation from the IR region; the bond vibration is fluctuated and causes an increase in vibrational energy.