The following two reactions give the same foul smelling product Z. X and Z, respectively, are :

Q: The following two reactions give the same foul smelling product Z. X and Z, respectively, are :

Step 1: Analyze the second reaction sequence (bottom). - C2H5CONH2 Br2, NaOH Y: This is Hoffmann bromamide degradation. The amide loses its carbonyl group to form a primary amine: C2H5NH2 (Y). - C2H5NH2 CHCl3 / KOH, Delta Z: This is the Carbylamine reaction (isocyanide test). Primary amines react to form highly offensive, foul-smelling isocyanides. Thus, Z is Ethyl isocyanide (C2H5NC). Step 2: Analyze the first reaction (top). - C2H5Cl X C2H5NC (Z). - To convert an alkyl chloride directly into a

Year	2024	Total
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2024

Total

Questions

Solution & Explanation

Core Logic

Step 1: Analyze the second reaction sequence (bottom).

$C₂H₅CONH₂ Br₂, NaOH Y$ : This is Hoffmann bromamide degradation. The amide loses its carbonyl group to form a primary amine: $C₂H₅NH₂$ $C_2H_5NH_2$ (Y).
$C₂H₅NH₂ CHCl₃ / KOH, Δ Z$ : This is the Carbylamine reaction (isocyanide test). Primary amines react to form highly offensive, foul-smelling isocyanides. Thus, Z is Ethyl isocyanide ( $C₂H₅NC$ $C_2H_5NC$).

Step 2: Analyze the first reaction (top).

$C₂H₅Cl X C₂H₅NC$ $C_2H_5Cl \xrightarrow{X} C_2H_5NC$ (Z).
To convert an alkyl chloride directly into an isocyanide, we use Silver Cyanide ( $AgCN$ $AgCN$) because it is predominantly covalent, ensuring bonding through the Nitrogen atom rather than the Carbon atom (which happens with ionic KCN).

Step 1: Final Conclusion

Therefore, Reagent X is $AgCN$ $AgCN$ and product Z is $C₂H₅NC$ $C_2H_5NC$.

Pattern Recognition

$AgCN$ $AgCN$ yields isocyanides ( $R-NC$ $R-NC$). $KCN$ $KCN$ yields cyanides/nitriles ( $R-CN$ $R-CN$). "Foul smelling" is the universal keyword for Carbylamine test (isocyanides).

Chapter Mix

Class 12 Chemistry: Amines Class 12 Chemistry: Haloalkanes and Haloarenes

Solution

Core Logic

Step 1: Free radical chlorination of Ethane:

C₂H₆ + Cl₂ UV C₂H₅Cl (X)

Step 2: Nucleophilic substitution (Ammonolysis):

C₂H₅Cl NH₃ C₂H₅NH₂ (Y)

Step 3: Diazotization and Hydration of aliphatic primary amine:

C₂H₅NH₂ NaNO₂ / HCl [C₂H₅N₂^+ Cl^-] H₂O C₂H₅OH + N₂ + HCl (Z)

Step 1: Final Conclusion

Solution for Q47 - Amines Reaction Scheme

The final major product Z is Ethanol (

C₂H₅OH

Pattern Recognition

Aliphatic primary amines react with nitrous acid ( $NaNO₂ + HCl$ $NaNO_2 + HCl$) to form unstable diazonium salts, which immediately decompose in water to yield the corresponding alcohol and release nitrogen gas.

Chapter Mix

Class 12 Chemistry: Amines Class 12 Chemistry: Haloalkanes and Haloarenes

Q61 neet_2026_03_may_morning Preparation of Amines

Select the reagents that reduce nitriles to primary amines. A. (i)

LiAlH₄

; (ii)

H₂O

B. Sn + HCl C.

H₂/Ni

Na(Hg)/C₂H₅OH

Br₂/aq. NaOH

Choose the correct answer from the options given below.

A. A, B and C only
B. A, C and D only
C. A, D and E only
D. B, D and E only

Solution

Core Logic

Reduction of Nitriles ( $R-CN$ $R-CN$) to Primary Amines ( $R-CH₂-NH₂$ $R-CH_2-NH_2$) can be achieved using strong reducing agents or catalytic hydrogenation:

$R-CN Na(Hg) / C₂H₅OH R-CH₂-NH₂$ (Mendius Reduction - Reagent D is correct)
$R-CN [(ii)H₂O](i)LiAlH₄ R-CH₂-NH₂$ (Strong Hydride Reduction - Reagent A is correct)
$R-CN H₂ / Ni R-CH₂-NH₂$ (Catalytic Hydrogenation - Reagent C is correct)

Incorrect Reagents:

$R-CN Sn + HCl R-CHO$ (Stephen reaction reduces nitriles to aldehydes, not amines - Reagent B is incorrect).
$Br₂/aq. NaOH$ $Br_2/aq. NaOH$ is used for Hoffmann bromamide degradation of amides, not nitriles (Reagent E is incorrect).

Step 1: Final Conclusion

Reagents A, C, and D are correct for reducing nitriles to primary amines.

Pattern Recognition

Nitriles require full reduction (addition of 4 Hydrogens) to become primary amines. Mild reducing agents like $Sn/HCl$ $Sn/HCl$ (Stephen's reduction) stop at the imine stage, hydrolyzing to an aldehyde.

Chapter Mix

Class 12 Chemistry: Amines

The following two reactions give the same foul smelling product Z. $C₂H₅CI X Z$ $C₂H₅CONH₂ Br₂, NaOH Y [Δ]CHCl₃ / ethanolic KOH Z$ X and Z, respectively, are :

Solution & Explanation

Core Logic

Step 1: Final Conclusion

Pattern Recognition

Chapter Mix

Reference Study Guides

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Solution

Core Logic

Step 1: Final Conclusion

Pattern Recognition

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Solution

Core Logic

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Pattern Recognition

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