Question 1: Palette 1/96

JEE Mains 2023 MCQ

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

Question 2: Palette 2/96

JEE Mains 2023 MCQ

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

Question 3: Palette 3/96

JEE Mains 2023 MCQ

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

$\dot{\mathrm{O}} \mathrm{H}$

Question 4: Palette 4/96

JEE Mains 2023 MCQ

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

Question 5: Palette 5/96

JEE Mains 2023 MCQ

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

$\mathrm{C}_{2} \mathrm{Cl}_{2} \mathrm{F}_{2}$

Question 6: Palette 6/96

JEE Mains 2023 MCQ

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

Question 7: Palette 7/96

JEE Mains 2023 MCQ

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

Question 8: Palette 8/96

JEE Mains 2023 MCQ

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)

Question 9: Palette 9/96

JEE Mains 2023 MCQ

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

$\mathrm{Cl\mathop O\limits^ \bullet (g) + O(g)\buildrel {} \over \longrightarrow C\mathop l\limits^ \bullet (g) + {O_2}(g)}$

Question 10: Palette 10/96

JEE Mains 2023 MCQ

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

Question 11: Palette 11/96

JEE Mains 2023 MCQ

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

Question 12: Palette 12/96

JEE Mains 2023 MCQ

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

Question 13: Palette 13/96

JEE Mains 2023 MCQ

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.

Question 14: Palette 14/96

JEE Mains 2023 MCQ

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

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

$\mathrm{X}=\mathrm{ClNO}_{2}, \mathrm{Y}=\mathrm{HCl}, \mathrm{Z}=\mathrm{HNO}_{3}$

Question 15: Palette 15/96

JEE Mains 2023 MCQ

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

Question 16: Palette 16/96

JEE Mains 2023 MCQ

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

$\mathrm{O}, \mathrm{NO} ~\mathrm{\&} ~\mathrm{NO}_{3}^{-}$

Question 17: Palette 17/96

JEE Mains 2023 MCQ

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

Question 18: Palette 18/96

JEE Mains 2023 MCQ

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

Question 19: Palette 19/96

JEE Mains 2023 MCQ

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

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

$\mathrm{X = NO,Y = [O],A = {O_2},B = {N_2}{O_3}}$

Question 20: Palette 20/96

JEE Mains 2023 MCQ

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

Question 21: Palette 21/96

JEE Mains 2023 MCQ

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

Question 22: Palette 22/96

JEE Mains 2022 MCQ

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

Question 23: Palette 23/96

JEE Mains 2022 MCQ

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

Question 24: Palette 24/96

JEE Mains 2022 MCQ

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

Question 25: Palette 25/96

JEE Mains 2022 MCQ

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

Question 26: Palette 26/96

JEE Mains 2022 MCQ

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

Question 27: Palette 27/96

JEE Mains 2022 MCQ

The photochemical smog does not generally contain :

A

NO

B

NO₂

C

SO₂

D

HCHO

Question 28: Palette 28/96

JEE Mains 2022 MCQ

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.

Question 29: Palette 29/96

JEE Mains 2022 MCQ

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.

Question 30: Palette 30/96

JEE Mains 2022 MCQ

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

Question 31: Palette 31/96

JEE Mains 2022 MCQ

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.

Question 32: Palette 32/96

JEE Mains 2022 MCQ

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

Question 33: Palette 33/96

JEE Mains 2022 MCQ

Polar stratospheric clouds facilitate the formation of :

A

ClONO₂

B

HOCl

C

ClO

D

CH₄

Question 34: Palette 34/96

JEE Mains 2022 MCQ

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.

Question 35: Palette 35/96

JEE Mains 2022 MCQ

The eutrophication of water body results in :

A

loss of Biodiversity.

B

breakdown of organic matter.

C

increase in biodiversity.

D

decrease in BOD.

Question 36: Palette 36/96

JEE Mains 2022 MCQ

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

Question 37: Palette 37/96

JEE Mains 2021 MCQ

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

Question 38: Palette 38/96

JEE Mains 2021 MCQ

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

Question 39: Palette 39/96

JEE Mains 2021 MCQ

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

Question 40: Palette 40/96

JEE Mains 2021 MCQ

In stratosphere most of the ozone formation is assisted by :

A

cosmic rays

B

$\gamma$-rays

C

ultraviolet radiation

D

visible radiations

Question 41: Palette 41/96

JEE Mains 2021 MCQ

Which one of the following is used to remove most of plutonium from spent nuclear fuel?

A

ClF₃

B

O₂F₂

C

I₂O₅

D

BrO₃

Question 42: Palette 42/96

JEE Mains 2021 MCQ

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

$\mathop C\limits^ \bullet l + C\mathop {{F_2}}\limits^ \bullet Cl$

Question 43: Palette 43/96

JEE Mains 2021 MCQ

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)

Question 44: Palette 44/96

JEE Mains 2021 MCQ

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]

Question 45: Palette 45/96

JEE Mains 2021 MCQ

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

Question 46: Palette 46/96

JEE Mains 2021 MCQ

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

Question 47: Palette 47/96

JEE Mains 2021 MCQ

Which one of the following gases is reported to retard photosynthesis?

A

CO

B

CFCs

C

CO₂

D

NO₂

Question 48: Palette 48/96

JEE Mains 2021 MCQ

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.

Question 49: Palette 49/96

JEE Mains 2021 MCQ

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

Question 50: Palette 50/96

JEE Mains 2021 MCQ

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

Question 51: Palette 51/96

JEE Mains 2021 MCQ

Reducing smog is a mixture of :

A

Smoke, fog and O₃

B

Smoke, fog and N₂O₃

C

Smoke, fog and CH₂ = CH $-$ CHO

D

Smoke, fog and SO₂

Question 52: Palette 52/96

JEE Mains 2021 MCQ

The green house gas/es is (are) :

(A) Carbon dioxide

(B) Oxygen

(C) Water vapour

(D) Methane

Choose the most appropriate answer from the options given below :

A

(A) and (C) only

B

(A) and (B) only

C

(A), (C) and (D) only

D

(A) only

Question 53: Palette 53/96

JEE Mains 2021 MCQ

The type of pollution that gets increased during the day time and in the presence of O₃ is :

A

Oxidising smog

B

Global warming

C

Acid rain

D

Reducing smog

Question 54: Palette 54/96

JEE Mains 2021 MCQ

The presence of ozone in troposphere :

A

protects us from greenhouse effect

B

protects us from the UV radiation

C

protects us from the X-ray radiation

D

generates photochemical smog

Question 55: Palette 55/96

JEE Mains 2021 MCQ

Given below are two statements :

Statement I : The pH of rain water is normally 5.6.

Statement II : If the pH of rain water drops below 5.6, it is called acid rain.

In the light of the above statements, choose the correct 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.

Question 56: Palette 56/96

JEE Mains 2021 MCQ

Given below are two statements :

Statement I : An allotrope of oxygen is an important intermediate in the formation of reducing smog.

Statement II : Gases such as oxides of nitrogen and sulphur present in troposphere contribute to the formation of photochemical smog.

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

A

Statement I is false but Statement II is true

B

Both Statement I and Statement II are false

C

Both Statement I and Statement II are true

D

Statement I is true but Statement II is false

Question 57: Palette 57/96

JEE Mains 2021 MCQ

Given below are two statements :

Statement I : The value of the parameter "Biochemical Oxygen Demand (BOD)" is important for survival of aquatic life.

Statement II : The optimum value of BOD is 6.5 ppm.

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

Statement I is true but Statement II is false

C

Both Statement I and Statement II are true

D

Both Statement I and Statement II are false

Question 58: Palette 58/96

JEE Mains 2021 MCQ

The gas released during anaerobic degradation of vegetation may lead to :

A

Ozone hole

B

Corrosion of metals

C

Acid rain

D

Global warming and cancer

Question 59: Palette 59/96

JEE Mains 2020 MCQ

The presence of soluble fluoride ion upto 1 ppm concentration in drinking water, is :

A

safe for teeth

B

harmful to skin

C

harmful for teeth

D

harmful to bones

Question 60: Palette 60/96

JEE Mains 2020 MCQ

The condition that indicates a polluted environment is :

A

BOD value of 5 ppm

B

eutrophication

C

0.03% of CO₂ in the atmosphere

D

pH of rain water to be 5.6

Question 61: Palette 61/96

JEE Mains 2020 MCQ

The processes of calcination and roasting in metallurgical industries, respectively, can Iead to :

A

Global warming and photochemical smog

B

Photochemical smog and ozone layer depletion

C

Photochemical smog and global warming

D

Global warming and acid rain

Question 62: Palette 62/96

JEE Mains 2020 MCQ

The incorrect statement(s) among (a) – (d) regarding acid rain is (are) :

(a) It can corrode water pipes.
(b) It can damage structures made up of stone.
(c) It cannot cause respiratory ailments in animals.
(d) It is not harmful for trees

A

(c) and (d)

B

(a), (b) and (d)

C

(c) only

D

(a), (c) and (d)

Question 63: Palette 63/96

JEE Mains 2020 MCQ

Thermal power plants can lead to :

A

Ozone layer depletion

B

Blue baby syndrome

C

Eutrophication

D

Acid rain

Question 64: Palette 64/96

JEE Mains 2020 MCQ

The statement that is not true about ozone is :

A

In the stratosphere, CFCs release chlorine free radicals (Cl) which reacts with O₃ to give chlorine dioxide radicals

B

It is a toxic gas and its reaction with NO gives NO₂.

C

In the atmosphere, it is depleted by CFCs

D

In the stratosphere, it forms a protective shield against UV radiation

Question 65: Palette 65/96

JEE Mains 2020 MCQ

Biochemical Oxygen Demand (BOD) is the amount of oxygen required (in ppm) :

A

for sustaining life in a water body.

B

by anaerobic bacteria to breakdown inorganic waste present in a water body.

C

for the photochemical breakdown of waste present in 1 m³ volume of a water body.

D

by bacteria to break-down organic waste in a certain volume of a water sample.

Question 66: Palette 66/96

JEE Mains 2020 MCQ

Among the gases (a) – (e), the gases that cause greenhouse effect are :
(a) CO₂
(b) H₂O
(c) CFCs
(d) O₂
(e) O₃

A

(a), (b), (c) and (d)

B

(a) and (d)

C

(a), (b), (c) and (e)

D

(a), (c), (d) and (e)

Question 67: Palette 67/96

JEE Mains 2019 MCQ

The primary pollutant that leads to photochemical smog is :

A

acrolein

B

ozone

C

sulphur dioxide

D

nitrogen oxides

Question 68: Palette 68/96

JEE Mains 2019 MCQ

The correct set of species responsible for the photochemical smog is :

A

NO, NO₂, O₃ and hydrocarbons

B

N₂, NO₂ and hydrocarbons

C

CO₂, NO₂, SO₂ and hydrocarbons

D

N₂, O₂, O₃ and hydrocarbons

Question 69: Palette 69/96

JEE Mains 2019 MCQ

Air pollution that occurs in sunlight is :

A

oxidising smog

B

reducing smog

C

fog

D

acid rain

Question 70: Palette 70/96

JEE Mains 2019 MCQ

The regions of the atmosphere, where clouds form and where we live, respectively, are :

A

Stratosphere and Stratosphere

B

Stratosphere and Troposphere

C

Troposphere and Stratosphere

D

Troposphere and Troposphere

Question 71: Palette 71/96

JEE Mains 2019 MCQ

The layer of atmosphere between 10 km to 50 km above the sea level is called as :

A

mesosphere

B

thermosphere

C

troposphere

D

stratosphere

Question 72: Palette 72/96

JEE Mains 2019 MCQ

Excessive release of CO₂ into the atomosphere results in :

A

depletion of ozone

B

polar vortex

C

global warming

D

formation of smog

Question 73: Palette 73/96

JEE Mains 2019 MCQ

The maximum prescribed concentration of copper in drinking water is :

A

3 ppm

B

5 ppm

C

0.5 ppm

D

0.05 ppm

Question 74: Palette 74/96

JEE Mains 2019 MCQ

Assertion : Ozone is destroyed by CFCs in the upper stratosphere.

Reason : Ozone holes increase the amount of UV radiation the earth.

A

Assertion and reason are both correct, and the reason is the correct explanation for the assertion.

B

Assertion and reason are incorrect.

C

Assertion and reason are correct but, the reason is not the explanation for the assertion

D

Assertion is false, but the reason is correct.

Question 75: Palette 75/96

JEE Mains 2019 MCQ

Which is wrong with respect to our responsiblity as a human being to protect our environment?

A

Restricting the use of vehicles

B

Setting up compost tin in gardens.

C

Avoiding the use of floodlighted facilities

D

Using plastic bags.

Question 76: Palette 76/96

JEE Mains 2019 MCQ

The compound that is NOT a common component of photochemical smog is :

A

O₃

B

C

CH₂ = CHCHO

D

CF₂Cl₂

Question 77: Palette 77/96

JEE Mains 2019 MCQ

The molecule that has minimum /no role in the formation of photochemical smog, is :

A

CH₂ = O

B

O₃

C

N₂

D

NO

Question 78: Palette 78/96

JEE Mains 2019 MCQ

Water samples with BOD values of 4 ppm and 18 ppm, respectively are :

A

Clean and Highly polluted

B

Highly polluted and Clean

C

Highly polluted and Highly polluted

D

Clean and Clean

Question 79: Palette 79/96

JEE Mains 2019 MCQ

Taj Mahal is being slowly disfigured and discoloured. This is primarily due to :

A

acid rain

B

soil pollution

C

global warming

D

water pollution

Question 80: Palette 80/96

JEE Mains 2019 MCQ

The higher concentration of which gas in air can cause stiffness of flower buds?

A

CO₂

B

SO₂

C

NO₂

D

CO

Question 81: Palette 81/96

JEE Mains 2019 MCQ

Peroxyacetyl nitrate (PAN), an eye irritant is produced by :

A

classical smog

B

acid rain

C

photochemical smog

D

organic waste

Question 82: Palette 82/96

JEE Mains 2019 MCQ

The concentration of dissolved oxygen (DO) in cold water can go upto :

A

14 ppm

B

16 ppm

C

8 ppm

D

10 ppm

Question 83: Palette 83/96

JEE Mains 2019 MCQ

The reaction that is NOT involved in the ozone layer depletion mechanism in the stratosphere is :

A

$Cl\mathop O\limits^ \bullet \left( g \right) + O\left( g \right) \to \mathop C\limits^ \bullet l\left( g \right) + {O_2}(g)$

B

$C{F_2}C{l_2}\left( g \right)\,\buildrel {uv} \over \longrightarrow \mathop {\,C}\limits^ \bullet l\left( g \right) + \mathop C\limits^ \bullet {F_2}Cl\left( g \right)$

C

$C{H_4} + 2{O_3}\, \to \,3C{H_2} = O + 3{H_2}O$

D

$HOCl\left( g \right)\,\buildrel {hv} \over \longrightarrow \,\mathop O\limits^ \bullet H\left( g \right) + \mathop C\limits^ \bullet l\left( g \right)$

Question 84: Palette 84/96

JEE Mains 2019 MCQ

Water filled in two glasses A and B have BOD values of 10 and 20, respectively. The correct statement regarding them, is :

A

B is more polluted than A.

B

A is suitable for drinking, whereas B is not .

C

Both A and B are suitable for dirnking

D

A is more polluted than B.

Question 85: Palette 85/96

JEE Mains 2019 MCQ

Which of the following conditions in drinking water causes methemoglobinemia?

A

> 50 ppm of lead

B

> 50 ppm of chloride

C

> 50 ppm of nitrate

D

> 100 ppm of sulphate

Question 86: Palette 86/96

JEE Mains 2019 MCQ

A water sample has ppm level concentration of the following metals : Fe = 0.2; Mn = 5.0; Cu = 3.0; Zn = 5.0. The metal that makes the water sample unsuitable for drinking is :

A

Cu

B

Mn

C

Fe

D

Zn

Question 87: Palette 87/96

JEE Mains 2018 MCQ

The recommended concentration of fluoride ion in drinking water is up to 1 ppm as fluoride ion is required to make teeth enamel harder by converting
[3Ca₃ (PO₄)₂.Ca(OH)₂] to

A

[3{Ca(OH)₂}. CaF₂]

B

[CaF₂]

C

[3(CaF₂). Ca(OH)₂]

D

[3Ca₃(PO₄)₂. CaF₂]

Question 88: Palette 88/96

JEE Mains 2018 MCQ

Biochemical Oxygen Demand (BOD) value can be a measure of water pollution caused by the organic matter. Which of the following statements is correct ?

A

Aerobic bacteria decrease the BOD value.

B

Anaerobic bacteria increase the BOD value.

C

Clean water has BOD value higher than 10 ppm.

D

Polluted water has BOD value higher than 10 ppm.

Question 89: Palette 89/96

JEE Mains 2017 MCQ

Which of the following is a set of greenhouse gases?

A

CH₄, O₃, N₂, SO₂

B

O₃, N₂, CO₂, NO₂

C

O₃, NO₂, SO₂, Cl₂

D

CO₂, CH₄, N₂O, O₃

Question 90: Palette 90/96

JEE Mains 2017 MCQ

Identify the pollutant gases largely responsible for the discoloured and lustreless nature of marble of the Taj Mahal.

A

O₃ and CO₂

B

CO₂ and NO₂

C

SO₂ and NO₂

D

SO₂ and O₃

Question 91: Palette 91/96

JEE Mains 2017 MCQ

A water sample has ppm level concentration of following anions
F^- = 10; $SO_4^{2-}$ = 100; $NO_3^-$ = 50
The anion/anions that make/makes the water sample unsuitable for drinking is/are :

A

both $SO_4^{2-}$ and $NO_3^-$

B

only F^-

C

only $SO_4^{2-}$

D

only $NO_3^-$

Question 92: Palette 92/96

JEE Mains 2016 MCQ

Which one of the following substances used in dry cleaning is a better strategy to control environmental pollution?

A

Tetrachloroethylene

B

Carbon dioxide

C

Sulphur dioxide

D

Nitrogen dioxide

Question 93: Palette 93/96

JEE Mains 2016 MCQ

BOD stands for :

A

Biological Oxygen Demand

B

Bacterial Oxidation Demand

C

Biochemical Oxygen Demand

D

Biochemical Oxidation Demand

Question 94: Palette 94/96

JEE Mains 2016 MCQ

The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to high concentration of :

A

Lead

B

Nitrate

C

Iron

D

Fluoride

Question 95: Palette 95/96

JEE Mains 2008 MCQ

Identify the wrong statements in the following :

A

Chlorofluorocarbons are responsible for ozone layer depletion

B

Greenhouse effect is responsible for global warming

C

Ozone layer does not permit infrared radiation from the sun to reach the earth

D

Acid rains is mostly because of oxides of nitrogen and sulphur

Question 96: Palette 96/96

JEE Mains 2004 MCQ

The smog is essentially caused by the presence of :

A

O₂ and O₃c

B

O₃ and N₂

C

Oxides of sulphur and nitrogen

D

O₂ and N₂