NEET 2027
HIGH-WEIGHTAGE CHEMISTRY
PART 4B (Questions 151–300)
ENVIRONMENTAL • EVERYDAY LIFE • PURIFICATION MIXED HIGH-DIFFICULTY PRACTICE
150 Unique Questions | Completes Part 4 (300 total)
Special Features
✓ Q151–300 – no overlap with any previous part
✓ Environmental, Everyday Life, Purification + Mixed
✓ Detailed why-correct / why-wrong for every question
✓ Completes full Chemistry set: 750 questions
, CONTENTS – PART 4B
6. Environmental Chemistry + Chemistry in Everyday Life — Q151 to Q200
7. Purification & Characterisation of Organic Compounds — Q201 to Q230
8. Mixed High-Difficulty Practice (All Chapters) — Q231 to Q300
NEET 2027 | Chemistry Part 4B Page 2
, 6. ENVIRONMENTAL CHEMISTRY + CHEMISTRY IN EVERYDAY LIFE
Greenhouse gases (CO■, CH■, N■O, CFCs), ozone depletion (Cl• from CFCs), acid rain (SO■, NO■), photochemical
smog (NO■ + hydrocarbons + sunlight → O■, PAN). BOD/COD, eutrophication, biodegradable vs non-biodegradable.
Drugs: analgesics, antibiotics, antiseptics, antacids, antihistamines, tranquillisers. Soaps (scum in hard water) vs
detergents (work in hard water); micelles. Artificial sweeteners, antioxidants, preservatives.
Q151. Greenhouse gas:
A. N■
B. O■
C. CO■
D. Ar
✓ Correct Answer: C
Why this is correct: CO■ is a major greenhouse gas (also CH■, N■O, CFCs, H■O vapour).
✗ Why the other options are wrong:
• A, B, D do not absorb IR significantly.
Q152. Main cause of ozone depletion:
A. CO■
B. CFCs
C. N■
D. O■
✓ Correct Answer: B
Why this is correct: Cl• from CFCs catalytically destroys stratospheric ozone.
✗ Why the other options are wrong:
• A greenhouse gas, not main ozone depleter.
Q153. Acid rain mainly from:
A. NO■ and SO■
B. Only CO■
C. Only CH■
D. Only O■
✓ Correct Answer: A
Why this is correct: SO■ and NO■ form H■SO■ and HNO■ in rain (pH < 5.6).
✗ Why the other options are wrong:
• B contributes weakly (H■CO■).
Q154. BOD means:
A. Biological Oxygen Demand
B. Biochemical Oxygen Demand
C. Both used
D. Bacterial only
✓ Correct Answer: C
Why this is correct: BOD = Biochemical/Biological Oxygen Demand – O■ needed by microbes to decompose organic matter.
✗ Why the other options are wrong:
• D not standard.
Q155. Biodegradable pollutant:
A. DDT
B. Most plastics
C. Domestic sewage
D. Mercury
✓ Correct Answer: C
Why this is correct: Domestic sewage is biodegradable. DDT, many plastics, Hg persist.
✗ Why the other options are wrong:
• A, B, D non-biodegradable/persistent.
Q156. Photochemical smog from:
A. NO■ + hydrocarbons + sunlight
B. Only SO■ + fog
C. Only CO■
D. Only CH■
NEET 2027 | Chemistry Part 4B Page 3
HIGH-WEIGHTAGE CHEMISTRY
PART 4B (Questions 151–300)
ENVIRONMENTAL • EVERYDAY LIFE • PURIFICATION MIXED HIGH-DIFFICULTY PRACTICE
150 Unique Questions | Completes Part 4 (300 total)
Special Features
✓ Q151–300 – no overlap with any previous part
✓ Environmental, Everyday Life, Purification + Mixed
✓ Detailed why-correct / why-wrong for every question
✓ Completes full Chemistry set: 750 questions
, CONTENTS – PART 4B
6. Environmental Chemistry + Chemistry in Everyday Life — Q151 to Q200
7. Purification & Characterisation of Organic Compounds — Q201 to Q230
8. Mixed High-Difficulty Practice (All Chapters) — Q231 to Q300
NEET 2027 | Chemistry Part 4B Page 2
, 6. ENVIRONMENTAL CHEMISTRY + CHEMISTRY IN EVERYDAY LIFE
Greenhouse gases (CO■, CH■, N■O, CFCs), ozone depletion (Cl• from CFCs), acid rain (SO■, NO■), photochemical
smog (NO■ + hydrocarbons + sunlight → O■, PAN). BOD/COD, eutrophication, biodegradable vs non-biodegradable.
Drugs: analgesics, antibiotics, antiseptics, antacids, antihistamines, tranquillisers. Soaps (scum in hard water) vs
detergents (work in hard water); micelles. Artificial sweeteners, antioxidants, preservatives.
Q151. Greenhouse gas:
A. N■
B. O■
C. CO■
D. Ar
✓ Correct Answer: C
Why this is correct: CO■ is a major greenhouse gas (also CH■, N■O, CFCs, H■O vapour).
✗ Why the other options are wrong:
• A, B, D do not absorb IR significantly.
Q152. Main cause of ozone depletion:
A. CO■
B. CFCs
C. N■
D. O■
✓ Correct Answer: B
Why this is correct: Cl• from CFCs catalytically destroys stratospheric ozone.
✗ Why the other options are wrong:
• A greenhouse gas, not main ozone depleter.
Q153. Acid rain mainly from:
A. NO■ and SO■
B. Only CO■
C. Only CH■
D. Only O■
✓ Correct Answer: A
Why this is correct: SO■ and NO■ form H■SO■ and HNO■ in rain (pH < 5.6).
✗ Why the other options are wrong:
• B contributes weakly (H■CO■).
Q154. BOD means:
A. Biological Oxygen Demand
B. Biochemical Oxygen Demand
C. Both used
D. Bacterial only
✓ Correct Answer: C
Why this is correct: BOD = Biochemical/Biological Oxygen Demand – O■ needed by microbes to decompose organic matter.
✗ Why the other options are wrong:
• D not standard.
Q155. Biodegradable pollutant:
A. DDT
B. Most plastics
C. Domestic sewage
D. Mercury
✓ Correct Answer: C
Why this is correct: Domestic sewage is biodegradable. DDT, many plastics, Hg persist.
✗ Why the other options are wrong:
• A, B, D non-biodegradable/persistent.
Q156. Photochemical smog from:
A. NO■ + hydrocarbons + sunlight
B. Only SO■ + fog
C. Only CO■
D. Only CH■
NEET 2027 | Chemistry Part 4B Page 3
