JEE Challenger
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ChemMedAdv 2025 • Paper 1

Match Organic Compounds with Chemical Tests and Observations

Match the compounds in List-I with the appropriate observations in List-II and choose the correct option.

List-IList-II(P)(1) Reaction with phenyl diazonium salt gives yellow dye.(Q)(2) Reaction with ninhydrin gives purple color and it also reacts with FeCl3 to give violet color.(R)(3) Reaction with glucose will give corresponding hydrazone.(S)(4) Lassaigne extract of the compound treated with dilute HCl followed by addition of aqueous FeCl3 gives blood red color.(5) After complete hydrolysis, it will give ninhydrin test and it DOES NOT give positive phthalein dye test.\begin{array}{ll} \textbf{List-I} & \textbf{List-II} \\ \text{(P)} & \text{(1) Reaction with phenyl diazonium salt gives yellow dye.} \\ \text{(Q)} & \text{(2) Reaction with ninhydrin gives purple color and it also reacts with } \text{FeCl}_3 \text{ to give violet color.} \\ \text{(R)} & \text{(3) Reaction with glucose will give corresponding hydrazone.} \\ \text{(S)} & \text{(4) Lassaigne extract of the compound treated with dilute } \text{HCl} \text{ followed by addition of aqueous } \text{FeCl}_3 \text{ gives blood red color.} \\ & \text{(5) After complete hydrolysis, it will give ninhydrin test and it } \textbf{DOES NOT} \text{ give positive phthalein dye test.} \end{array}
Question Diagram 1
Question Diagram 2
Question Diagram 3
Question Diagram 4

Options

A

P→1; Q→5; R→4; S→2\text{P} \rightarrow 1;\ \text{Q} \rightarrow 5;\ \text{R} \rightarrow 4;\ \text{S} \rightarrow 2

B

P→2; Q→5; R→1; S→3\text{P} \rightarrow 2;\ \text{Q} \rightarrow 5;\ \text{R} \rightarrow 1;\ \text{S} \rightarrow 3

Correct
C

P→5; Q→2; R→1; S→4\text{P} \rightarrow 5;\ \text{Q} \rightarrow 2;\ \text{R} \rightarrow 1;\ \text{S} \rightarrow 4

D

P→2; Q→1; R→5; S→3\text{P} \rightarrow 2;\ \text{Q} \rightarrow 1;\ \text{R} \rightarrow 5;\ \text{S} \rightarrow 3

Topics & Concepts

BiomoleculesAmino Acids and ProteinsAminesCarbohydrates

Step-by-Step Solution

To determine the correct matching between the compounds in List-I and the observations in List-II, let us analyze each compound individually:

  1. Compound (P):

    • Structure: It is a peptide derivative containing a free primary α\alpha-amino group (−NH2-\text{NH}_2) and a phenolic hydroxyl group (−OH-\text{OH}).
    • Reactivity:
      • Due to the presence of the free α\alpha-amino group, it gives a positive ninhydrin test yielding a purple-colored complex (Ruhemann's purple).
      • Due to the phenolic −OH-\text{OH} group, it reacts with neutral FeCl3\text{FeCl}_3 solution to form a characteristic violet-colored coordination complex.
    • Therefore, P→2\mathbf{P \rightarrow 2}.

  2. Compound (Q):

    • Structure: It is an NN-acetylated dipeptide methyl ester with no free amino or phenolic group.
    • Reactivity:
      • Upon complete acid/base hydrolysis, the amide and ester linkages are cleaved to liberate free α\alpha-amino acids (α\alpha-phenylglycine and valine).
      • These released amino acids give a positive ninhydrin test.
      • Since the compound lacks a phenolic moiety, it does not give the phthalein dye test.
    • Therefore, Q→5\mathbf{Q \rightarrow 5}.

  3. Compound (R):

    • Structure: Anilinium chloride (C6H5NH3+Cl−\text{C}_6\text{H}_5\text{NH}_3^+\text{Cl}^-), which in basic/neutral conditions releases aniline (C6H5NH2\text{C}_6\text{H}_5\text{NH}_2).
    • Reactivity:
      • Aniline undergoes an azo-coupling reaction with benzenediazonium chloride (phenyldiazonium salt) at its para-position to form pp-aminoazobenzene, which is a well-known yellow dye.
    • Therefore, R→1\mathbf{R \rightarrow 1}.

  4. Compound (S):

    • Structure: 2,4,6-trimethylphenylhydrazine (a substituted arylhydrazine derivative containing a −NHNH2-\text{NHNH}_2 functional group).
    • Reactivity:
      • Hydrazines react with the aldehyde/hemiacetal group of reducing sugars like D-glucose to form the corresponding hydrazone.
    • Therefore, S→3\mathbf{S \rightarrow 3}.

Matching all pairs: P→2;Q→5;R→1;S→3\text{P} \rightarrow 2; \quad \text{Q} \rightarrow 5; \quad \text{R} \rightarrow 1; \quad \text{S} \rightarrow 3

Thus, the correct option is (B).

Match Organic Compounds with Chemical Tests and Observations | Chemistry PYQ Solution - JEE Challenger