Environmental Chemistry

2023 Q1 JEE Mains MCQ
14 Mar 2026
The possibility of photochemical smog formation will be minimum at :
A.
Mumbai in May
B.
Kolkata in October
C.
New-Delhi in August (Summer)
D.
Srinagar, Jammu and Kashmir in January
2023 Q2 JEE Mains MCQ
14 Mar 2026

Which of the following are the Green house gases?

A. Water vapour

B. Ozone

C. I$_2$

D. Molecular hydrogen

Choose the most appropriate answer from the options given below :

A.
A and D only
B.
A and B only
C.
B and C only
D.
C and D only
2023 Q3 JEE Mains MCQ
14 Mar 2026

The radical which mainly causes ozone depletion in the presence of UV radiations is :

A.
$\mathrm{NO}^\cdot$
B.
$\mathrm{CH}_{3} ^\cdot$
C.
$\dot{\mathrm{Cl}}$
D.
$\dot{\mathrm{O}} \mathrm{H}$
2023 Q4 JEE Mains MCQ
14 Mar 2026

Match List I with List II

LIST I LIST II
A. Nitrogen oxides in air I. Eutrophication
B. Methane in air II. pH of rain water becomes 5.6
C. Carbon dioxide III. Global warming
D. Phosphate fertilisers in water IV. Acid rain

Choose the correct answer from the options given below :

A.
A-II, B-III, C-I, D-IV
B.
A-I, B-II, C-III, D-IV
C.
A-IV, B-II, C-III, D-I
D.
A-IV, B-III, C-II, D-I
2023 Q5 JEE Mains MCQ
14 Mar 2026

Which of the following compounds is an example of Freon?

A.
$\mathrm{C}_{2} \mathrm{H}_{2} \mathrm{F}_{2}$
B.
$\mathrm{C}_{2} \mathrm{HF}_{3}$
C.
$\mathrm{C}_{2} \mathrm{F}_{4}$
D.
$\mathrm{C}_{2} \mathrm{Cl}_{2} \mathrm{F}_{2}$
2023 Q6 JEE Mains MCQ
14 Mar 2026

Given below are two statements:

Statement I : If BOD is 4 ppm and dissolved oxygen is 8 ppm, then it is a good quality water.

Statement II : If the concentration of zinc and nitrate salts are $5 ~\mathrm{ppm}$ each, then it can be a good quality water.

In the light of the above statements, choose the most appropriate answer from the options given below :

A.
Statement I is incorrect but Statement II is correct
B.
Both the statements I and II are incorrect
C.
Both the statements I and II are correct
D.
Statement I is correct but Statement II is incorrect
2023 Q7 JEE Mains MCQ
14 Mar 2026

The delicate balance of $\mathrm{CO}_{2}$ and $\mathrm{O}_{2}$ is NOT disturbed by :

A.
Burning of Coal
B.
Burning of petroleum
C.
Respiration
D.
Deforestation
2023 Q8 JEE Mains MCQ
14 Mar 2026

Match List I with List II

List I
Industry
List II
Waste Generated
(A) Steel plants (I) Gypsum
(B) Thermal power plants (II) Fly ash
(C) Fertilizer industries (III) Slag
(D) Paper mills (IV) Bio-degradable wastes

Choose the correct answer from the options given below :

A.
(A)-(III), (B)-(II), (C)-(I), (D)-(IV)
B.
(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
C.
(A)-(IV), (B)-(I), (C)-(II), (D)-(III)
D.
(A)-(II), (B)-(III), (C)-(IV), (D)-(I)
2023 Q9 JEE Mains MCQ
14 Mar 2026

Which of these reactions is not a part of breakdown of ozone in stratosphere?

A.
$\mathrm{C{F_2}C{l_2}(g)\buildrel {uv} \over \longrightarrow \mathop C\limits^ \bullet l(g) + \mathop C\limits^ \bullet {F_2}Cl(g)}$
B.
$\mathrm{C\mathop l\limits^ \bullet (g) + {O_3}(g)\buildrel {} \over \longrightarrow Cl\mathop O\limits^ \bullet (g) + {O_2}(g)}$
C.
$\mathrm{2Cl\mathop O\limits^ \bullet \buildrel {} \over \longrightarrow Cl{O_2}(g) + C\mathop l\limits^ \bullet (g)}$
D.
$\mathrm{Cl\mathop O\limits^ \bullet (g) + O(g)\buildrel {} \over \longrightarrow C\mathop l\limits^ \bullet (g) + {O_2}(g)}$
2023 Q10 JEE Mains MCQ
14 Mar 2026

Match List I with List II:

LIST I
(Species)
LIST II
(Maximum allowed concentration in ppm in drinking water)
A. $\mathrm{F^-}$ I. < 50 ppm
B. $\mathrm{SO_4^{2-}}$ II. < 5 ppm
C. $\mathrm{NO_3^-}$ III. < 2 ppm
D. $\mathrm{Zn}$ IV. < 500 ppm

Choose the correct answer from the options given below :

A.
A-IV, B-III, C-II, D-I
B.
A-I, B-II, C-III, D-IV
C.
A-II, B-I, C-III, D-IV
D.
A-III, B-IV C-I, D-II
2023 Q11 JEE Mains MCQ
14 Mar 2026

The possibility of photochemical smog formation is more at :

A.
Industrial areas
B.
Himalayan villages in winter
C.
The places with healthy vegetation
D.
Marshy lands
2023 Q12 JEE Mains MCQ
14 Mar 2026

The industrial activity held least responsible for global warming is :

A.
manufacturing of cement
B.
Electricity generation in thermal power plants
C.
steel manufacturing
D.
Industrial production of urea
2023 Q13 JEE Mains MCQ
14 Mar 2026

How can photochemical smog be controlled?

A.
By using catalytic convertors in the automobiles/industry.
B.
By complete combustion of fuel.
C.
By using tall chimneys.
D.
By using catalyst.
2023 Q14 JEE Mains MCQ
14 Mar 2026

Identify X, Y and Z in the following reaction. (Equation not balanced)

JEE Main 2023 (Online) 31st January Morning Shift Chemistry - Environmental Chemistry Question 19 English

A.
$\mathrm{X}=\mathrm{ClONO}_{2}, \mathrm{Y}=\mathrm{HOCl}, \mathrm{Z}=\mathrm{NO}_{2}$
B.
$\mathrm{X}=\mathrm{ClNO}_{3}, \mathrm{Y}=\mathrm{Cl}_{2}, \mathrm{Z}=\mathrm{NO}_{2}$
C.
$\mathrm{X}=\mathrm{ClONO}_{2}, \mathrm{Y}=\mathrm{HOCl}, \mathrm{Z}=\mathrm{HNO}_{3}$
D.
$\mathrm{X}=\mathrm{ClNO}_{2}, \mathrm{Y}=\mathrm{HCl}, \mathrm{Z}=\mathrm{HNO}_{3}$
2023 Q15 JEE Mains MCQ
14 Mar 2026
The water quality of a pond was analyzed and its BOD was found to be 4. The pond has :
A.
Very clean water
B.
Highly polluted water
C.
Water has high amount of fluoride compounds
D.
Slightly polluted water
2023 Q16 JEE Mains MCQ
14 Mar 2026

Formation of photochemical smog involves the following reaction in which $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ are respectively.

$ \begin{aligned} & \text { i. } \mathrm{NO}_{2} \stackrel{\mathrm{h} v}{\longrightarrow} \mathrm{A}+\mathrm{B} \\ & \text { ii. } \mathrm{B}+\mathrm{O}_{2} \rightarrow \mathrm{C} \\ & \text { iii. } \mathrm{A}+\mathrm{C} \rightarrow \mathrm{NO}_{2}+\mathrm{O}_{2} \end{aligned} $

Choose the correct answer from the options given below :

A.
$\mathrm{NO}, \mathrm{O} ~\& ~\mathrm{O}_{3}$
B.
$\mathrm{N}, \mathrm{O}_{2} ~\& ~\mathrm{O}_{3}$
C.
$\mathrm{O}, \mathrm{N}_{2} \mathrm{O} ~\& ~\mathrm{NO}$
D.
$\mathrm{O}, \mathrm{NO} ~\mathrm{\&} ~\mathrm{NO}_{3}^{-}$
2023 Q17 JEE Mains MCQ
14 Mar 2026

The concentration of dissolved Oxygen in water for growth of fish should be more than $\mathrm{\underline X }$ ppm and Biochemical Oxygen Demand in clean water should be less than $\mathrm{\underline Y }$ ppm. X and Y in ppm are, respectively.

A.
$\mathrm{X}$ $\mathrm{Y}$
4 15
B.
$\mathrm{X}$ $\mathrm{Y}$
4 8
C.
$\mathrm{X}$ $\mathrm{Y}$
6 12
D.
$\mathrm{X}$ $\mathrm{Y}$
6 5
2023 Q18 JEE Mains MCQ
14 Mar 2026

Correct statement about smog is :

A.
NO$_2$ is present in classical smog
B.
Both NO$_2$ and SO$_2$ are present in classical smog
C.
Photochemical smog has high concentration of oxidizing agents
D.
Classical smog also has high concentration of oxidizing agents
2023 Q19 JEE Mains MCQ
14 Mar 2026

Some reactions of NO$_2$ relevant to photochemical smog formation are

JEE Main 2023 (Online) 25th January Morning Shift Chemistry - Environmental Chemistry Question 14 English

Identify A, B, X and Y :

A.
$\mathrm{X = [O],Y = NO,A = {O_2},B = {O_3}}$
B.
$\mathrm{X = {N_2}O,Y = [O],A = {O_3},B = NO}$
C.
$\mathrm{X = {1 \over 2}{O_2},Y = N{O_2},A = {O_3},B = {O_2}}$
D.
$\mathrm{X = NO,Y = [O],A = {O_2},B = {N_2}{O_3}}$
2023 Q20 JEE Mains MCQ
14 Mar 2026

Correct statement is :

A.
An average human being consumes more food than air
B.
An average human being consumes 100 times more air than food
C.
An average human being consumes nearly 15 times more air than food
D.
An average human being consumes equal amount of food and air
2023 Q21 JEE Mains MCQ
14 Mar 2026

Which of the following is true about freons?

A.
These are radicals of chlorine and chlorine monoxide
B.
These are chemicals causing skin cancer
C.
All radicals are called freons
D.
These are chlorofluorocarbon compounds
2022 Q22 JEE Mains MCQ
14 Mar 2026

Which among the following pairs has only herbicides?

A.
Aldrin and Dieldrin
B.
Sodium chlorate and Aldrin
C.
Sodium arsinate and Dieldrin
D.
Sodium chlorate and sodium arsinite
2022 Q23 JEE Mains MCQ
14 Mar 2026

Given below are two statements:

Statement I : In polluted water values of both dissolved oxygen and $\mathrm{BOD}$ are very low.

Statement II : Eutrophication results in decrease in the amount of dissolved oxygen.

In the light of the above statements, choose the most appropriate answer from the options given below :

A.
Both Statement I and Statement II are true
B.
Both Statement I and Statement II are false
C.
Statement I is true but Statement II is false
D.
Statement I is false but Statement II is true
2022 Q24 JEE Mains MCQ
14 Mar 2026

Given below are two statements:

Statement I : The non bio-degradable fly ash and slag from steel industry can be used by cement industry.

Statement II : The fuel obtained from plastic waste is lead free.

In the light of the above statements, choose the most appropriate answer from the options given below :

A.
Both Statement I and Statement II are correct
B.
Both Statement I and Statement II are incorrect
C.
Statement I is correct but Statement II is incorrect
D.
Statement I is incorrect but Statement II is correct
2022 Q25 JEE Mains MCQ
14 Mar 2026

Match List I with List II.

List I

Pollutant
List II

Disease/sickness
(A) Sulphate (>500 ppm) (I) Methemoglobinemia
(B) Nitrate (>50 ppm) (II) Brown mottling of teeth
(C) Lead (>50 ppb) (III) Laxative effect
(D) Fluoride (>2 ppm) (IV) Kidney damage

Choose the correct answer from the options given below :

A.
A-IV, B-I, C-II, D-III
B.
A-III, B-I, C-IV, D-II
C.
A-II, B-IV, C-I, D-III
D.
A-II, B-IV, C-III, D-I
2022 Q26 JEE Mains MCQ
14 Mar 2026

Match List I with List II.

List I

Pollutant
List II

Source
(A) Microorganisms (I) Strip mining
(B) Plant nutrients (II) Domestic sewage
(C) Toxic heavy metals (III) Chemical fertilizer
(D) Sediment (IV) Chemical factory

Choose the correct answer from the options given below :

A.
A-II, B-III, C-IV, D-I
B.
A-II, B-I, C-IV D-III
C.
A-I, B-IV, C-II, D-III
D.
A-I, B-IV, C-III, D-II
2022 Q27 JEE Mains MCQ
14 Mar 2026

The photochemical smog does not generally contain :

A.
NO
B.
NO2
C.
SO2
D.
HCHO
2022 Q28 JEE Mains MCQ
14 Mar 2026

The acid that is believed to be mainly responsible for the damage of Taj Mahal is :

A.
sulfuric acid.
B.
hydrofluoric acid.
C.
phosphoric acid.
D.
hydrochloric acid.
2022 Q29 JEE Mains MCQ
14 Mar 2026

Correct statement about photo-chemical smog is :

A.
It occurs in humid climate.
B.
It is a mixture of smoke, fog and SO2.
C.
It is reducing smog.
D.
It results from reaction of unsaturated hydrocarbons.
2022 Q30 JEE Mains MCQ
14 Mar 2026

On the surface of polar stratospheric clouds, hydrolysis of chlorine nitrite gives A and B while its reaction with its reaction with HCl produces B and C. A, B and C are, respectively :

A.
HOCl, HNO3, Cl2
B.
Cl2, HNO3, HOCl
C.
HClO2, HNO2, HOCl
D.
HOCl, HNO2, Cl2O
2022 Q31 JEE Mains MCQ
14 Mar 2026

Given below are two Statements:

Statement I : Classical smog occurs in cool humid climate. It is a reducing mixture of smoke, fog and sulphur dioxide.

Statement II : Photochemical smog has components, ozone, nitric oxide, acrolein, formaldehyde, PAN etc.

In the light of the above statements, choose the most appropriate answer from the options given below.

A.
Both Statement I and Statement II are correct.
B.
Both Statement I and Statement II are incorrect.
C.
Statement I is correct but Statement II is incorrect.
D.
Statement I is incorrect but Statement II is correct.
2022 Q32 JEE Mains MCQ
14 Mar 2026

The measured BOD values for four different water samples (A-D) are as follows: A = 3 ppm; B = 18 ppm; C = 21 ppm; D = 4 ppm. The water samples which can be called as highly polluted with organic wastes, are :

A.
A and B
B.
A and D
C.
B and C
D.
B and D
2022 Q33 JEE Mains MCQ
14 Mar 2026

Polar stratospheric clouds facilitate the formation of :

A.
ClONO2
B.
HOCl
C.
ClO
D.
CH4
2022 Q34 JEE Mains MCQ
14 Mar 2026

Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Polluted water may have a value of BOD of the order of 17 ppm.

Reason R : BOD is a measure of oxygen required to oxidise both the bio-degradable an non-biodegradable organic material in water.

In the light of the above statements, choose the most appropriate answer from the options given below.

A.
Both A and R are correct and R is the correct explanation of A.
B.
Both A and R are correct but R is NOT the correct explanation of A.
C.
A is correct but R is not correct.
D.
A is not correct but R is correct.
2022 Q35 JEE Mains MCQ
14 Mar 2026

The eutrophication of water body results in :

A.
loss of Biodiversity.
B.
breakdown of organic matter.
C.
increase in biodiversity.
D.
decrease in BOD.
2022 Q36 JEE Mains MCQ
14 Mar 2026

Some gases are responsible for heating of atmosphere (green house effect). Identify from the following the gaseous species which does not cause it.

A.
CH4
B.
O3
C.
H2O
D.
N2
2021 Q37 JEE Mains MCQ
14 Mar 2026
Water sample is called cleanest on the basis of which one of the BOD values given below :
A.
11 ppm
B.
15 ppm
C.
3 ppm
D.
21 ppm
2021 Q38 JEE Mains MCQ
14 Mar 2026
The deposition of X and Y on ground surfaces is referred as wet and dry depositions, respectively. X and Y are :
A.
X = Ammonium salts, Y = CO2
B.
X = SO2, Y = Ammonium salts
C.
X = Ammonium salts, Y = SO2
D.
X = CO2, Y = SO2
2021 Q39 JEE Mains MCQ
14 Mar 2026
BOD values (in ppm) for clean water (A) and polluted water (B) are expected respectively :
A.
A > 50, B < 27
B.
A > 25, B < 17
C.
A < 5, B > 17
D.
A > 15, B > 47
2021 Q40 JEE Mains MCQ
14 Mar 2026
In stratosphere most of the ozone formation is assisted by :
A.
cosmic rays
B.
$\gamma$-rays
C.
ultraviolet radiation
D.
visible radiations
2021 Q41 JEE Mains MCQ
14 Mar 2026
Which one of the following is used to remove most of plutonium from spent nuclear fuel?
A.
ClF3
B.
O2F2
C.
I2O5
D.
BrO3
2021 Q42 JEE Mains MCQ
14 Mar 2026
The gas 'A' is having very low reactivity reaches to stratosphere. It is non-toxic and non-flammable but dissociated by UV-radiations in stratosphere. The intermediates formed initially from the gas 'A' are :
A.
$Cl\mathop O\limits^ \bullet + \mathop C\limits^ \bullet {F_2}Cl$
B.
$Cl\mathop O\limits^ \bullet + C\mathop {{H_3}}\limits^ \bullet $
C.
$\mathop C\limits^ \bullet {H_3} + C\mathop {{F_2}}\limits^ \bullet Cl$
D.
$\mathop C\limits^ \bullet l + C\mathop {{F_2}}\limits^ \bullet Cl$
2021 Q43 JEE Mains MCQ
14 Mar 2026
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Photochemical smog causes cracking of rubber.

Reason (R) : Presence of ozone, nitric oxide, acrolein, formaldehyde and peroxyacetyl nitrate in photochemical smog makes it oxidizing.

Choose the most appropriate answer from the options given below :
A.
Both (A) and (R) are true but (R) is not the true explanation of (A)
B.
(A) is false but (R) is true.
C.
(A) is true but (R) is false.
D.
Both (A) and (R) are true and (R) is the true explanation of (A)
2021 Q44 JEE Mains MCQ
14 Mar 2026
The conversion of hydroxyapatite occurs due to presence of F$-$ ions in water. The correct formula of hydroxyapatite is :
A.
[3Ca3(PO4)2 . Ca(OH)2]
B.
[3Ca(OH)2 . CaF2]
C.
[Ca3(PO4)2 . CaF2]
D.
[3Ca3(PO4)2 . CaF2]
2021 Q45 JEE Mains MCQ
14 Mar 2026
Which one of the following statements is NOT correct?
A.
Eutrophication indicates that water body is polluted
B.
The dissolved oxygen concentration below 6 ppm inhibits fish growth
C.
Eutrophication leads to increase in the oxygen level in water
D.
Eutrophication leads to anaerobic conditions
2021 Q46 JEE Mains MCQ
14 Mar 2026
Given below are two statements :

Statement I : Chlorofluoro breakdown by radiation in the visible energy region and release chlorine gas in the atmosphere which then reacts with stratospheric ozone.

Statement II : Atmospheric ozone reacts with nitric oxide to give nitrogen and oxygen gases, which add to the atmosphere.

For the above statements choose the correct answer from the options given below :
A.
Statement I is incorrect but Statement II is true
B.
Both Statement I and II are false
C.
Statement I is correct but Statement II is false
D.
Both Statement I and II are correct
2021 Q47 JEE Mains MCQ
14 Mar 2026
Which one of the following gases is reported to retard photosynthesis?
A.
CO
B.
CFCs
C.
CO2
D.
NO2
2021 Q48 JEE Mains MCQ
14 Mar 2026
Given below are two statements :

Statement I : Non-biodegradable wastes are generated by the thermal power plants.

Statement II : Bio-degradable detergents leads to eutrophication.

In the light of the above statements, choose the most appropriate answer from the options given below :
A.
Statement I is false but statement II is true.
B.
Both statement I and statement II are true.
C.
Both statement I and statement II are false.
D.
Statement I is true but statement is false.
2021 Q49 JEE Mains MCQ
14 Mar 2026
The statements that are TRUE :

(A) Methane leads to both global warming and photochemical smog

(B) Methane is generated from paddy fields

(C) Methane is a stronger global warming gas than CO2

(D) Methane is a part of reducing smog

Choose the most appropriate answer from the options given below :
A.
(A), (B), (C) only
B.
(A) and (B) only
C.
(B), (C), (D) only
D.
(A), (B), (D) only
2021 Q50 JEE Mains MCQ
14 Mar 2026
Which of the following statement(s) is (are) incorrect reason for eutrophication?

(A) excess usage of fertilisers

(B) excess usage of detergents

(C) dense plant population in water bodies

(D) lack of nutrients in water bodies that prevent plant growth

Choose the most appropriate answer from the options given below :
A.
(A) Only
B.
(B) and (D) only
C.
(C) only
D.
(D) only