Chemistry — Organic Chemistry for the NEET Exam

Common failure modes

These are the patterns that cause most candidates to lose marks on this topic. Recognising them in advance is half the work.

• !Confusing Markovnikov's rule for HBr addition with the anti-Markovnikov product formed in the presence of peroxides
• !Forgetting that carbohydrates are classified by the number of carbon atoms and the functional group (aldose vs ketose)
• !Misidentifying peptide bond formation and hydrolysis direction
• !Confusing addition polymer (polyethene) with condensation polymer (nylon, polyester) types
• !Selecting the wrong Tollens' vs Fehling's test for aldehydes — both are correct but the distinction matters for reducing sugars

Study tips

• 1Study NCERT Class 12 Organic Chemistry chapters in order: Haloalkanes → Alcohols/Phenols/Ethers → Aldehydes/Ketones/Carboxylic Acids → Amines → Biomolecules → Polymers. The logic builds sequentially.
• 2Make a named-reaction chart for NEET: Aldol condensation, Cannizzaro, Reimer-Tiemann, Kolbe's synthesis, Sandmeyer, Balz-Schiemann, Hoffmann bromamide, Wolff-Kishner.
• 3For biomolecules, memorise: glucose structure (open-chain and Haworth), classification of amino acids (acidic, basic, neutral, essential), DNA vs RNA differences (sugar, base, structure).
• 4Drill reducing sugars vs non-reducing sugars: all monosaccharides reduce Fehling; sucrose (non-reducing disaccharide) does not.
• 5Do NEET PYQ Organic Chemistry sets from the last 5 years — the question style is highly repetitive.

Sample NEET Chemistry — Organic Chemistry questions

These sample items mirror the format and difficulty of real NEET questions. Practice with thousands more on the free Koydo question bank.

1. 1

   Which of the following sugars is a non-reducing sugar?

   • AGlucose
   • BFructose
   • CMaltose
   • DSucroseCorrect
   Why this answer?

   Sucrose is a non-reducing sugar because it is formed by the linkage of glucose (C1) and fructose (C2) through both anomeric carbons (C1 of glucose and C2 of fructose), leaving no free aldehyde or ketone group to reduce Fehling's or Tollens' reagent. All monosaccharides and most disaccharides (maltose, lactose) are reducing sugars.

2. 2

   Nylon-6,6 is an example of:

   • AAddition polymer
   • BCondensation polymerCorrect
   • CNatural polymer
   • DElastomer
   Why this answer?

   Nylon-6,6 is formed by the condensation of hexamethylenediamine and adipic acid with the elimination of water molecules, forming amide linkages (−CO−NH−). Condensation polymers lose small molecules (H₂O, HCl) during formation. Addition polymers (like polyethene) form without loss of any atom.

3. 3

   Which test is used to distinguish a primary amine from a secondary amine?

   • ATollens' test
   • BHinsberg testCorrect
   • CLucas test
   • DFehling test
   Why this answer?

   The Hinsberg test uses benzenesulfonyl chloride: primary amines form a sulfonamide soluble in NaOH; secondary amines form a sulfonamide insoluble in NaOH; tertiary amines don't react. This distinguishes 1°, 2°, and 3° amines.