NEET PYQ Patterns and Highest-Probability Questions

Pattern 1 — Monomer-Polymer Matching (highest frequency): Question format: "Which monomer gives Nylon-6?" or "Match the polymers with their monomers." Must know: Nylon-6 ↔ Caprolactam (ring-opening, 1 monomer). Nylon-6,6 ↔ HMD + Adipic acid (2 monomers, 6C each). Dacron ↔ Ethylene glycol + Terephthalic acid. Bakelite ↔ Phenol + HCHO. Probability: 1 question in almost every NEET year.

Pattern 2 — HDPE/LDPE Conditions (very high frequency): Question format: "HDPE is made by..." with options that reverse conditions. Must know: HDPE = ZN + low P (linear). LDPE = radical + 1000–2000 atm (branched). Probability: appears every 2–3 years, usually as the hardest chemistry question in polymer section.

Pattern 3 — Acid Rain pH (high frequency): Question format: "Acid rain has pH less than ___?" or "Normal rain pH is ___?" Must know: Normal = 5.6. Acid rain = below 5.6. Distractor = pH 7. Probability: 1 question every 2–3 years.

Pattern 4 — London vs Photochemical Smog: Question format: "Photochemical smog contains ___?" or classify smog type. Must know: London = SO2 + reducing. Photo = O3 + PAN + oxidizing + eye irritation. Probability: 1 question every 2–4 years.

Pattern 5 — BOD and Water Pollution: Question format: "Which BOD value indicates polluted water?" Must know: clean < 5 ppm; sewage > 17 ppm. Higher BOD = more polluted. Probability: 1 question every 2–3 years.

Pattern 6 — Heavy Metal Diseases: Question format: "Minamata disease is caused by ___?" or "Cadmium causes ___ disease." Must know: Hg → Minamata. Cd → Itai-Itai. Pb → neurological. Probability: 1 question every 2–3 years.

Pattern 7 — Ozone Depletion: Question format: "Which species catalytically destroys ozone?" or "How many O3 molecules does one Cl• destroy?" Must know: Cl• is the catalyst; ~100,000 O3 destroyed per Cl•.