The following two reactions give the same foul-smelling product Z. Reaction 1: C2H5Cl + X -> Z Reaction 2: C2H5CONH2 ->[Br2, NaOH] Y ->[CHCl3 / ethanolic KOH][ ] Z X and Z, respectively, are :

Correct answer: (A) (A) X = AgCN; Z = C2H5NC. AgCN is a covalent, ambident nucleophile that bonds through nitrogen, so C2H5Cl + AgCN -> C2H5NC + AgCl gives ethyl isocyanide (X = AgCN, Z = C2H5NC). In Reaction 2, C2H5CONH2 undergoes Hofmann degradation to ethylamine C2H5NH2 (Y), which on the carbylamine reaction (CHCl3 + ethanolic KOH) also gives the foul-smelling isocyanide C2H5NC (Z). Both routes converge on the same isocyanide.

NEET 2026 (Phase 1) · ChemistryPrevious Year Question

The following two reactions give the same foul-smelling product $Z$ . Reaction 1: $C X_{2} H X_{5} Cl + X Z$ Reaction 2: $C X_{2} H X_{5} CONH X_{2} Br X_{2}, NaOH$ $Y$ $CHCl3 / ethanolic KOH Δ$ $Z$ $X$ and $Z$ , respectively, are :

Answer: (A) (A) $X = AgCN$ ; $Z = C X_{2} H X_{5} NC$ . $AgCN$ is a covalent, ambident nucleophile that bonds through nitrogen, so $C X_{2} H X_{5} Cl + AgCN C X_{2} H X_{5} NC + AgCl$ gives ethyl isocyanide ( $X = AgCN$ , $Z = C X_{2} H X_{5} NC$ ).

A.(A) $X = AgCN$ ; $Z = C X_{2} H X_{5} NC$ ✓
B.(B) $X = KCN$ ; $Z = C X_{2} H X_{5} CN$
C.(C) $X = AgCN$ ; $Z = C X_{2} H X_{5} CN$
D.(D) $X = KCN$ ; $Z = C X_{2} H X_{5} NC$

Correct Answer

(A) (A) $X = AgCN$ ; $Z = C X_{2} H X_{5} NC$

Solution & Explanation

$AgCN$ is a covalent, ambident nucleophile that bonds through nitrogen, so $C X_{2} H X_{5} Cl + AgCN C X_{2} H X_{5} NC + AgCl$ gives ethyl isocyanide ( $X = AgCN$ , $Z = C X_{2} H X_{5} NC$ ). In Reaction 2, $C X_{2} H X_{5} CONH X_{2}$ undergoes Hofmann degradation to ethylamine $C X_{2} H X_{5} NH X_{2}$ ( $Y$ ), which on the carbylamine reaction ( $CHCl X_{3}$ + ethanolic KOH) also gives the foul-smelling isocyanide $C X_{2} H X_{5} NC$ ( $Z$ ). Both routes converge on the same isocyanide.

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The following two reactions give the same foul-smelling product Z. Reaction 1: CX2​HX5​Cl+X​Z Reaction 2: CX2​HX5​CONHX2​BrX2​, NaOH​ Y CHCl3 / ethanolic KOHΔ​ Z X and Z, respectively, are :

Solution & Explanation

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The following two reactions give the same foul-smelling product $Z$ . Reaction 1: $C X_{2} H X_{5} Cl + X Z$ Reaction 2: $C X_{2} H X_{5} CONH X_{2} Br X_{2}, NaOH$ $Y$ $CHCl3 / ethanolic KOH Δ$ $Z$ $X$ and $Z$ , respectively, are :