Polymers & Everyday Chemistry · JEE Main previous year questions

2025 2 questions

1. Q612025 · 4 Apr 2025 · Shift 2

   A toxic compound \" A \" when reacted with $\text{NaCN}$ in aqueous acidic medium yields an edible cooking component and food preservative \" B \". \" B \" is converted to \" C \" by diborane and can be used as an additive to petrol to reduce emission. \"C\" upon reaction with oleum at $140^{\circ }\text{C}$ yields an inhalable anesthetic \" D \". Identify \" A \", \" B \", \" C \" & \" D \", respectively :

   1. A.Methanol; acetic acid; ethanol; diethyl ether
   2. B.Ethanol; acetonitrile; ethylamine; ethylene
   3. C.Methanol; formaldehyde; methyl chloride; chloroform
   4. D.Acetaldehyde; 2-hydroxypropanoic acid; propanoic acid; dipropyl ether
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   Answer: A

2. Q692025 · 29 Jan 2025 · Shift 2

   Drug $X$ becomes ineffective after $50\%$ decomposition. The original concentration of drug in a bottle was $16mg/mL$ which becomes $4mg/mL$ in 12 months. The expiry time of the drug in months is ____. Assume that the decomposition of the drug follows first order kinetics.

   1. A.12
   2. B.3
   3. C.6
   4. D.2
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   Answer: C