JEE-MAIN SERIES Chemistry
Environmental Chemistry
41 previous year questions.
Volume: 41 Ques
Yield: High
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2015 Chapter Questions 41 MCQs
01
PYQ 2015
hard
chemistry ID: jee-main
Addition of phosphate fertilisers to water bodies causes :
1
enhanced growth of algae
2
increase in amount of dissolved oxygen in water
3
deposition of calcium phosphate
4
increase in fish population
02
PYQ 2016
medium
chemistry ID: jee-main
BOD stands for:
1
Biological Oxygen Demand
2
Bacterial Oxidation Demand
3
Biochemical Oxygen Demand
4
Biochemical Oxidation Demand
03
PYQ 2017
medium
chemistry ID: jee-main
A water sample has ppm level concentration of following anions The anion/anions that make/makes the water sample unsuitable for drinking is / are :
1
only
2
only
3
only
4
only and
04
PYQ 2018
medium
chemistry ID: jee-main
Biochemical Oxygen Demand (BOD) value can be a measure of water pollution caused by the organic matter. Which of the following statements is correct ?
1
Aerobic bacteria decrease the BOD value
2
Anaerobic bacteria increase the BOD value
3
Clean water has BOD value higher than 10 ppm
4
Polluted water has BOD value higher than 10 ppm
05
PYQ 2019
medium
chemistry ID: jee-main
A water sample has ppm level concentration of the following metals: The metal that makes the water sample unsuitable drinking is
1
Zn
2
Fe
3
Mn
4
Cu
06
PYQ 2019
medium
chemistry ID: jee-main
Ozone is destroyed by CFCs in the upper stratosphere Ozone holes increase the amount of UV radiation reaching the earth.
1
Assertion and reason are correct, but the reason is not the explanation for the assertion
2
Assertion is false, but the reason is correct
3
Assertion and reason are incorrect, Assertion and reason are both correct
4
And the reason is the correct explanation for the assertion
07
PYQ 2019
medium
chemistry ID: jee-main
The upper stratosphere consisting of the ozone layer protects us from the sun's radiation that falls in the wavelength region of :
1
600-750 nm
2
0.8-1.5 nm
3
400-550 nm
4
200-315 nm
08
PYQ 2019
medium
chemistry ID: jee-main
Which is wrong with respect to our responsibility as a human being to protect our environment ?
1
Avoiding the use of floodlighted facilities
2
Restricting the use of vehicles
3
Using plastic bags
4
Setting up compost tin in gardens
09
PYQ 2021
medium
chemistry ID: jee-main
In stratosphere most of the ozone formation is assisted by :
1
-rays.
2
visible radiations.
3
ultraviolet radiation.
4
cosmic rays.
10
PYQ 2021
medium
chemistry ID: jee-main
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 :
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 :
1
Both (A) and (R) are true and (R) is the true explanation of (A).
2
Both (A) and (R) are true but (R) is not the true explanation of (A).
3
(A) is true but (R) is false.
4
(A) is false but (R) is true.
11
PYQ 2021
medium
chemistry ID: jee-main
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.
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.
1
Both Statement I and Statement II are true.
2
Both Statement I and Statement II are false.
3
Statement I is true but Statement II is false.
%
%
4
Statement I is false but Statement II is true.
12
PYQ 2021
medium
chemistry ID: jee-main
Given below are two statements : Statement I : Non-biodegradable wastes are generated by the thermal power plants. Statement II : Bio-degradable detergents lead to eutrophication. In the light of the above statements, choose the most appropriate answer from the options given below :
1
Both statement I and statement II are true.
2
Both statement I and statement II are false.
3
Statement I is true but statement II is false.
4
Statement I is false but statement II is true.
13
PYQ 2021
medium
chemistry ID: jee-main
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 :
1
(A) and (B) only
2
(A), (B), (C) only
3
(B), (C), (D) only
4
(A), (B), (D) only
14
PYQ 2021
medium
chemistry ID: jee-main
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:
1
2
3
4
15
PYQ 2021
medium
chemistry ID: jee-main
The deposition of X and Y on ground surfaces is referred as wet and dry depositions, respectively. X and Y are :
1
X = Ammonium salts , Y =
2
X = , Y =
3
X = , Y = Ammonium salts
4
X = Ammonium salts , Y =
16
PYQ 2021
medium
chemistry ID: jee-main
BOD values (in ppm) for clean water (A) and polluted water (B) are expected respectively as :
1
2
3
4
17
PYQ 2021
medium
chemistry ID: jee-main
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 :
1
Both Statement I and Statement II are true
2
Both Statement I and Statement II are false
3
Statement I is true but Statement II is false
4
Statement I is false but Statement II is true
18
PYQ 2021
medium
chemistry ID: jee-main
Match List - I with List - II : 
Choose the correct answer from the options given below :
1
(a) - (iii), (b) - (iv), (c) - (i), (d) - (ii)
2
(a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)
3
(a) - (iv), (b) - (i), (c) - (iii), (d) - (ii)
4
(a) - (i), (b) - (ii), (c) - (iii), (d) - (iv)
19
PYQ 2021
medium
chemistry ID: jee-main
Which one of the following chemical agent is not being used for dry-cleaning of clothes ?
1
2
3
Liquid
4
20
PYQ 2021
medium
chemistry ID: jee-main
The gas released during anaerobic degradation of vegetation may lead to :
1
Acid rain
2
Global warming and cancer
3
Corrosion of metals
4
Ozone hole
21
PYQ 2021
medium
chemistry ID: jee-main
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 :
1
Both Statement I and Statement II are true
2
Both Statement I and Statement II are false
3
Statement I is true but Statement II is false
4
Statement I is false but Statement II is true
22
PYQ 2021
medium
chemistry ID: jee-main
Which one of the following statements is NOT correct ?
1
The dissolved oxygen concentration below 6 ppm inhibits fish growth
2
Eutrophication indicates that water body is polluted
3
Eutrophication leads to increase in the oxygen level in water
4
Eutrophication leads to anaerobic conditions
23
PYQ 2022
medium
chemistry ID: jee-main
Animal starch is the other name of
1
amylose
2
maltose
3
glycogen
4
amylopectin
24
PYQ 2022
medium
chemistry ID: jee-main
Sulphur dioxide is one of the components of polluted air. SO2 is also a major contributor to acid rain. The correct and complete reaction to represent acid rain caused by SO2 is
1
2SO2 + O2 → 2SO3
2
SO2 + O3 → SO3 + O2
3
SO2 + H2O2 → H2SO4
4
2SO2 + O2 + 2H2O → 2H2SO4
25
PYQ 2022
medium
chemistry ID: jee-main
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:
1
A-II, B-III, C-IV, D-I
2
A-II, B-I, C-IV, D-III
3
A-I, B-IV, C-II, D-III
4
A-I, B-IV, C-III, D-II
26
PYQ 2022
medium
chemistry ID: jee-main
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 = 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
1
A and B
2
A and D
3
B and C
4
B and D
27
PYQ 2022
medium
chemistry ID: jee-main
The photochemical smog does not generally contain :
1
2
3
4
28
PYQ 2022
medium
chemistry ID: jee-main
Dinitrogen and dioxygen, the main constituents of air do not react with each other in atmosphere to form oxides of nitrogen because
1
N2 is unreactive in the condition of atmosphere
2
Oxides of nitrogen are unstable
3
Reaction between them can occur in the presence of a catalyst
4
The reaction is endothermic and require very high temperature
29
PYQ 2022
medium
chemistry ID: jee-main
Correct statement about photo-chemical smog is:
1
It occurs in humid climate.
2
It is a mixture of smoke, fog and SO2.
3
It is reducing smog.
4
It results from reaction of unsaturated hydrocarbons
30
PYQ 2022
medium
chemistry ID: jee-main
The mixture of chloroxylenol and terpineol is an example of
1
Antiseptic
2
Pesticide
3
Disinfectant
4
Narcotic analgesic
31
PYQ 2023
medium
chemistry ID: jee-main
Correct statement about smog is
1
NO2 is present in classical smog
2
Classical smog also has high concentration of oxidizing agents
3
Photochemical smog has high concentration of oxidizing agents
4
Both NO2 and SO2 are present in classical smog
32
PYQ 2023
medium
chemistry ID: jee-main
Photochemical smog found mainly in
1
Industrial area
2
Marshy place
3
Hilly area of Himachal
4
Cold humid climate
33
PYQ 2023
easy
chemistry ID: jee-main
In which of the following cities photochemical smog is minimum?
1
New Delhi
2
Mumbai
3
J & K
4
Kolkata
34
PYQ 2023
medium
chemistry ID: jee-main
Consider the following:
- D.D.T.
- Aldrin
- Sodium arsenite
- Sodium chlorate
1
1
2
2
3
3
4
4
35
PYQ 2023
medium
chemistry ID: jee-main
Formation of photochemical smog involves the following reaction in which and are respectively i ii iii Choose the correct answer from the options given below:
1
2
3
4
36
PYQ 2023
easy
chemistry ID: jee-main
Which of the following free radicals helps in depletion of the ozone layer?
1
NO
2
Cl
3
OH
4
CH3
37
PYQ 2023
medium
chemistry ID: jee-main
Which of these reactions is not a part of breakdown of ozone in stratosphere?
1
2
3
4
38
PYQ 2023
medium
chemistry ID: jee-main
Given below are two statements:
Statement I: If BOD value is 4 ppm and dissolved oxygen is 8 ppm, it is a good quality water.
Statement II: If the concentration of zinc and nitrate is 5 ppm, then it can be used as good quality water.
Statement I: If BOD value is 4 ppm and dissolved oxygen is 8 ppm, it is a good quality water.
Statement II: If the concentration of zinc and nitrate is 5 ppm, then it can be used as good quality water.
1
Statement I is correct but statement II is incorrect
2
Statement I is incorrect but statement II is correct
3
Both statements I and II are incorrect
4
Both statements I and II are correct
39
PYQ 2023
medium
chemistry ID: jee-main
Match the following List-I and List-II:
Choose the correct answer from the options given below:
| 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) | Ppaer mills | (IV) | Bio-degradable Wastes |
1
(A)-(III), (B)-(II), (C)-(I), (D)-(IV)
2
(A)-(III), (B)-(IV), (C)-(I), (D)-(II)
3
(A)-(II), (B)-(III), (C)-(IV), (D)-(I)
4
(A)-(IV), (B)-(I), (C)-(II), (D)-(III)
40
PYQ 2023
medium
chemistry ID: jee-main
The concentration of dissolved Oxygen in water for growth of fish should be more than 𝑋 ppm and Biochemical Oxygen Demand in clean water should be less than 𝑌 ppm. X and Y in ppm are, respectively.
1
X Y
4 8
4 8
2
X Y
6 5
6 5
3
X Y
4 15
4 15
4
X Y
6 12
6 12
41
PYQ 2024
medium
chemistry ID: jee-main
Identify the incorrect pair from the following:
1
Fluorspar -
2
Cryolite -
3
Fluoroapatite -
4
Carnallite -
About Environmental Chemistry - JEE-MAIN
Environmental Chemistry is a vital chapter for JEE-MAIN aspirants. Mastering the concepts covered in this chapter is essential for securing a top rank.
By rigorously practicing the previous year questions associated with this chapter, you can identify high-yield topics, understand the examiner's perspective, and boost your confidence during the actual exam.
Frequently Asked Questions
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Review the topic breakdown to see which sub-topics within Environmental Chemistry carry the most weight. Then, tackle the questions iteratively to solidify your understanding.