JEE Chemistry Environmental Chemistry MCQs Set 13

Answer: (c) \( \ce{CaCN2 + C} \)

Explanation:
1. Nitrolim is a nitrogenous fertiliser made by heating calcium carbide in nitrogen: \( \ce{CaC2 + N2 -> CaCN2 + C} \).
2. It is therefore a mixture of calcium cyanamide and carbon, \( \ce{CaCN2 + C} \).
3. In the soil it reacts with water to give ammonia: \( \ce{CaCN2 + 3H2O -> CaCO3 + 2NH3} \).

Teacher's Note:
1. N
2. i
3. t
4. r
5. o
6. l
7. i
8. m
9.
10. i
11. s
12.
13. n
14. o
15. t
16.
17. p
18. u
19. r
20. e
21.
22. c
23. a
24. l
25. c
26. i
27. u
28. m
29.
30. c
31. y
32. a
33. n
34. a
35. m
36. i
37. d
38. e
39. ;
40.
41. t
42. h
43. e
44.
45. c
46. a
47. r
48. b
49. o
50. n
51.
52. f
53. r
54. o
55. m
56.
57. c
58. a
59. r
60. b
61. i
62. d
63. e
64.
65. s
66. t
67. a
68. y
69. s
70.
71. i
72. n
73.
74. i
75. t
76. .
77.
78. I
79. t
80. s
81.
82. s
83. l
84. o
85. w
86.
87. r
88. e
89. l
90. e
91. a
92. s
93. e
94.
95. o
96. f
97.
98. a
99. m
100. m
101. o
102. n
103. i
104. a
105.
106. m
107. a
108. k
109. e
110. s
111.
112. i
113. t
114.
115. a
116.
117. u
118. s
119. e
120. f
121. u
122. l
123.
124. f
125. e
126. r
127. t
128. i
129. l
130. i
131. s
132. e
133. r
134. .

Answer: (c) \( \ce{N2} \)

Explanation:
1. Greenhouse gases absorb and re-emit infrared radiation from the earth.
2. Carbon dioxide, water vapour and ozone all trap heat.
3. Nitrogen is a diatomic homonuclear gas that does not absorb infrared radiation, so it is not a greenhouse gas.

Teacher's Note:
1. O
2. n
3. l
4. y
5.
6. g
7. a
8. s
9. e
10. s
11.
12. w
13. h
14. o
15. s
16. e
17.
18. m
19. o
20. l
21. e
22. c
23. u
24. l
25. e
26. s
27.
28. h
29. a
30. v
31. e
32.
33. a
34.
35. c
36. h
37. a
38. n
39. g
40. i
41. n
42. g
43.
44. d
45. i
46. p
47. o
48. l
49. e
50.
51. d
52. u
53. r
54. i
55. n
56. g
57.
58. v
59. i
60. b
61. r
62. a
63. t
64. i
65. o
66. n
67.
68. a
69. b
70. s
71. o
72. r
73. b
74.
75. i
76. n
77. f
78. r
79. a
80. r
81. e
82. d
83.
84. s
85. t
86. r
87. o
88. n
89. g
90. l
91. y
92. .
93.
94. N
95. ₂
96.
97. a
98. n
99. d
100.
101. O
102. ₂
103.
104. d
105. o
106.
107. n
108. o
109. t
110. .

Answer: (c) Oxygen

Explanation:
1. Carbon dioxide, water vapour and methane absorb infrared radiation and warm the atmosphere.
2. Oxygen, like nitrogen, does not absorb infrared radiation significantly.
3. So oxygen is the one that is not a greenhouse gas.

Teacher's Note:
1. M
2. e
3. t
4. h
5. a
6. n
7. e
8.
9. i
10. s
11.
12. a
13. b
14. o
15. u
16. t
17.
18. 2
19. 5
20.
21. t
22. i
23. m
24. e
25. s
26.
27. m
28. o
29. r
30. e
31.
32. e
33. f
34. f
35. e
36. c
37. t
38. i
39. v
40. e
41.
42. t
43. h
44. a
45. n
46.
47. c
48. a
49. r
50. b
51. o
52. n
53.
54. d
55. i
56. o
57. x
58. i
59. d
60. e
61.
62. p
63. e
64. r
65.
66. m
67. o
68. l
69. e
70. c
71. u
72. l
73. e
74.
75. o
76. v
77. e
78. r
79.
80. 1
81. 0
82. 0
83.
84. y
85. e
86. a
87. r
88. s
89. .
90.
91. T
92. h
93. e
94.
95. m
96. a
97. i
98. n
99.
100. a
101. t
102. m
103. o
104. s
105. p
106. h
107. e
108. r
109. i
110. c
111.
112. g
113. a
114. s
115. e
116. s
117.
118. N
119. ₂
120.
121. a
122. n
123. d
124.
125. O
126. ₂
127.
128. a
129. r
130. e
131.
132. n
133. o
134. t
135.
136. g
137. r
138. e
139. e
140. n
141. h
142. o
143. u
144. s
145. e
146.
147. g
148. a
149. s
150. e
151. s
152. .

Answer: (a) \( \ce{CF2Cl2} \)

Explanation:
1. Ultraviolet light breaks \( \ce{CF2Cl2} \) (a chlorofluorocarbon) to release chlorine atoms: \( \ce{CF2Cl2 -> CF2Cl. + Cl.} \).
2. Chlorine atoms catalytically destroy ozone: \( \ce{Cl. + O3 -> ClO. + O2} \) and \( \ce{ClO. + O -> Cl. + O2} \).
3. The other compounds contain no chlorine that can be freed in the stratosphere.

Teacher's Note:
1. O
2. n
3. e
4.
5. c
6. h
7. l
8. o
9. r
10. i
11. n
12. e
13.
14. a
15. t
16. o
17. m
18.
19. c
20. a
21. n
22.
23. d
24. e
25. s
26. t
27. r
28. o
29. y
30.
31. t
32. h
33. o
34. u
35. s
36. a
37. n
38. d
39. s
40.
41. o
42. f
43.
44. o
45. z
46. o
47. n
48. e
49.
50. m
51. o
52. l
53. e
54. c
55. u
56. l
57. e
58. s
59.
60. b
61. e
62. c
63. a
64. u
65. s
66. e
67.
68. i
69. t
70.
71. i
72. s
73.
74. r
75. e
76. g
77. e
78. n
79. e
80. r
81. a
82. t
83. e
84. d
85.
86. i
87. n
88.
89. t
90. h
91. e
92.
93. c
94. y
95. c
96. l
97. e
98. .
99.
100. F
101. r
102. e
103. o
104. n
105. s
106.
107. a
108. r
109. e
110.
111. t
112. h
113. e
114.
115. c
116. h
117. i
118. e
119. f
120.
121. o
122. z
123. o
124. n
125. e
126. -
127. d
128. e
129. p
130. l
131. e
132. t
133. i
134. n
135. g
136.
137. s
138. u
139. b
140. s
141. t
142. a
143. n
144. c
145. e
146. s
147. .

Answer: (d) \( \ce{O3} \) and PAN

Explanation:
1. Photochemical smog forms when primary pollutants, nitrogen oxides and hydrocarbons, react in sunlight.
2. The products are secondary pollutants: ozone \( \ce{O3} \) and peroxyacyl nitrates (PAN), along with aldehydes.
3. Hence \( \ce{O3} \) and PAN are the secondary pollutants.

Teacher's Note:
1. P
2. r
3. i
4. m
5. a
6. r
7. y
8.
9. p
10. o
11. l
12. l
13. u
14. t
15. a
16. n
17. t
18. s
19.
20. a
21. r
22. e
23.
24. e
25. m
26. i
27. t
28. t
29. e
30. d
31.
32. d
33. i
34. r
35. e
36. c
37. t
38. l
39. y
40. ,
41.
42. w
43. h
44. e
45. r
46. e
47. a
48. s
49.
50. s
51. e
52. c
53. o
54. n
55. d
56. a
57. r
58. y
59.
60. p
61. o
62. l
63. l
64. u
65. t
66. a
67. n
68. t
69. s
70.
71. a
72. r
73. e
74.
75. f
76. o
77. r
78. m
79. e
80. d
81.
82. i
83. n
84.
85. t
86. h
87. e
88.
89. a
90. t
91. m
92. o
93. s
94. p
95. h
96. e
97. r
98. e
99. .
100.
101. L
102. o
103. s
104.
105. A
106. n
107. g
108. e
109. l
110. e
111. s
112. -
113. t
114. y
115. p
116. e
117.
118. s
119. m
120. o
121. g
122.
123. i
124. s
125.
126. o
127. x
128. i
129. d
130. i
131. s
132. i
133. n
134. g
135. ,
136.
137. u
138. n
139. l
140. i
141. k
142. e
143.
144. L
145. o
146. n
147. d
148. o
149. n
150.
151. s
152. m
153. o
154. g
155. .

Answer: (c) (ii) only

Explanation:
1. The reddish-brown colour comes from nitrogen dioxide, \( \ce{NO2} \), emitted by vehicles.
2. Oxides of sulphur, carbon dioxide and smoke do not give a red haze.
3. So the red haze is due to oxides of nitrogen, (ii) only.

Teacher's Note:
1. B
2. r
3. o
4. w
5. n
6.
7. \
8. (
9.
10. \
11. c
12. e
13. {
14. N
15. O
16. 2
17. }
18.
19. \
20. )
21.
22. g
23. a
24. s
25.
26. i
27. s
28.
29. t
30. h
31. e
32.
33. c
34. a
35. u
36. s
37. e
38.
39. o
40. f
41.
42. t
43. h
44. e
45.
46. r
47. e
48. d
49.
50. h
51. a
52. z
53. e
54.
55. i
56. n
57.
58. h
59. e
60. a
61. v
62. y
63.
64. t
65. r
66. a
67. f
68. f
69. i
70. c
71. .
72.
73. I
74. t
75.
76. a
77. l
78. s
79. o
80.
81. t
82. a
83. k
84. e
85. s
86.
87. p
88. a
89. r
90. t
91.
92. i
93. n
94.
95. f
96. o
97. r
98. m
99. i
100. n
101. g
102.
103. p
104. h
105. o
106. t
107. o
108. c
109. h
110. e
111. m
112. i
113. c
114. a
115. l
116.
117. s
118. m
119. o
120. g
121. .

Answer: (b) Both A and R are true, but R is not the correct explanation of A.

Explanation:
1. Photochemical smog forms from nitrogen oxides and hydrocarbons in sunlight, so the assertion is true.
2. Vehicles are indeed a major source of nitrogen oxides, so the reason is true.
3. The reason tells where the oxides come from, not how smog is produced, so it does not explain the assertion.

Teacher's Note:
1. C
2. h
3. e
4. c
5. k
6.
7. w
8. h
9. e
10. t
11. h
12. e
13. r
14.
15. t
16. h
17. e
18.
19. r
20. e
21. a
22. s
23. o
24. n
25.
26. e
27. x
28. p
29. l
30. a
31. i
32. n
33. s
34.
35. t
36. h
37. e
38.
39. a
40. s
41. s
42. e
43. r
44. t
45. i
46. o
47. n
48. ,
49.
50. n
51. o
52. t
53.
54. m
55. e
56. r
57. e
58. l
59. y
60.
61. w
62. h
63. e
64. t
65. h
66. e
67. r
68.
69. i
70. t
71.
72. i
73. s
74.
75. t
76. r
77. u
78. e
79. .
80.
81. H
82. e
83. r
84. e
85.
86. t
87. h
88. e
89.
90. t
91. w
92. o
93.
94. f
95. a
96. c
97. t
98. s
99.
100. a
101. r
102. e
103.
104. r
105. e
106. l
107. a
108. t
109. e
110. d
111.
112. b
113. u
114. t
115.
116. i
117. n
118. d
119. e
120. p
121. e
122. n
123. d
124. e
125. n
126. t
127. .

Answer: (b) Both A and R are true, but R is not the correct explanation of A.

Explanation:
1. Diesel engines release fine particles (SPM, diameter below 10 micrometre), so the assertion is true.
2. Catalytic converters convert CO, NO and unburnt hydrocarbons into harmless products, so the reason is true.
3. The reason does not explain why diesel vehicles release SPM, so it is not the correct explanation.

Teacher's Note:
1. T
2. h
3. r
4. e
5. e
6. -
7. w
8. a
9. y
10.
11. c
12. a
13. t
14. a
15. l
16. y
17. t
18. i
19. c
20.
21. c
22. o
23. n
24. v
25. e
26. r
27. t
28. e
29. r
30. s
31.
32. m
33. a
34. i
35. n
36. l
37. y
38.
39. c
40. o
41. n
42. t
43. r
44. o
45. l
46.
47. C
48. O
49. ,
50.
51. N
52. O
53. x
54.
55. a
56. n
57. d
58.
59. h
60. y
61. d
62. r
63. o
64. c
65. a
66. r
67. b
68. o
69. n
70. s
71. .
72.
73. T
74. h
75. e
76. y
77.
78. a
79. r
80. e
81.
82. a
83.
84. p
85. o
86. l
87. l
88. u
89. t
90. i
91. o
92. n
93. -
94. c
95. o
96. n
97. t
98. r
99. o
100. l
101.
102. d
103. e
104. v
105. i
106. c
107. e
108. ,
109.
110. n
111. o
112. t
113.
114. t
115. h
116. e
117.
118. c
119. a
120. u
121. s
122. e
123.
124. o
125. f
126.
127. S
128. P
129. M
130.
131. r
132. e
133. l
134. e
135. a
136. s
137. e
138. .