Pattern 1: Polymer-Monomer Matching (Most Frequent)

NEET 2022, 2019, 2017 type: "Which monomer gives nylon-6?" or "Which polymer is formed from caprolactam?"

• Key tested pairs: Nylon-6 ↔ Caprolactam; Nylon-6,6 ↔ HMD + Adipic acid; Dacron ↔ Ethylene glycol + Terephthalic acid; Bakelite ↔ Phenol + HCHO.
• Trap: Nylon-6 vs Nylon-6,6 monomer count reversal.

Pattern 2: HDPE vs LDPE Conditions

NEET 2023, 2020 type: "Which is the correct preparation condition for HDPE?"

• Key facts: HDPE = ZN catalyst + low P; LDPE = free radical + 1000–2000 atm.
• Trap: Options always reverse the conditions — read carefully.

Pattern 3: Smog Type Identification

NEET 2021, 2018 type: "Which pollutant is associated with photochemical smog?" or "Classify London smog."

• Key tested facts: London smog = SO2 + particulates + reducing. Photochemical = O3 + PAN + oxidizing.
• Trap: PAN as a specific component of photochemical smog (not London smog); eye irritation = photochemical smog only.

Pattern 4: Acid Rain pH

NEET 2022, 2016 type: "What is the pH of acid rain?" or "What is the pH of normal rain?"

• Key fact: Normal rain = 5.6 (CO2); acid rain = below 5.6.
• Trap: Answer "below 7" = wrong; must say "below 5.6."

Pattern 5: BOD and Water Pollution

NEET 2020, 2017 type: "A BOD value of ___ indicates polluted water."

• Key scale: <5 ppm = clean; >17 ppm = heavily polluted/sewage.

Pattern 6: Heavy Metal Diseases

NEET multiple years: "Which disease is caused by cadmium?" or "Minamata disease is caused by?"

• Key pairs: Hg → Minamata; Cd → Itai-Itai; Pb → neurological damage.

Scoring Strategy

• Guarantee 6/6 on polymer questions: memorize all monomer-polymer pairs cold.
• Guarantee 1/1 on acid rain: write "5.6" in your notes 10 times before the exam.
• BOD values: clean < 5, polluted > 17 — no other values tested.