Amines are organic compounds derived from
A ammonia
B nitric acid
C nitrous acid
D nitriles
Amines are formed by replacing hydrogen atoms of ammonia with alkyl/aryl groups.
Primary amines have general formula
A R₂NH
B R₃N
C RNH₂
D R₄N⁺
One alkyl group attached to nitrogen.
Which is a secondary amine
A CH₃NH₂
B (CH₃)₂NH
C (CH₃)₃N
D NH₃
Two alkyl groups attached to nitrogen.
Which amine is tertiary
A ethylamine
B diethylamine
C triethylamine
D aniline
Three alkyl groups attached to nitrogen.
Amines are basic because
A nitrogen is electronegative
B lone pair on nitrogen
C resonance
D hydrogen bonding
Lone pair accepts proton.
Order of basicity of aliphatic amines in aqueous solution is
A 1° > 2° > 3°
B 2° > 1° > 3°
C 3° > 2° > 1°
D all equal
Solvation and steric effects influence basicity.
Aromatic amines are less basic than aliphatic amines due to
A steric hindrance
B resonance of lone pair
C inductive effect
D hydrogen bonding
Lone pair delocalises into ring.
Which amine is strongest base
A aniline
B ammonia
C methylamine
D nitroaniline
+I effect increases electron density.
Aniline is less basic than ammonia because
A −I effect
B steric hindrance
C resonance donation to ring
D hydrogen bonding
Lone pair participates in resonance.
Amines react with nitrous acid to give
A alcohol
B diazonium salt
C nitro compound
D aldehyde
Primary aromatic amines form diazonium salts.
Diazotisation is carried out at
A room temperature
B 50°C
C 0–5°C
D −20°C
Diazonium salts are unstable at higher temperature.
Primary aliphatic amines on reaction with nitrous acid give
A diazonium salt
B alcohol
C nitro compound
D nitrile
Unstable aliphatic diazonium salts decompose.
Secondary amines with nitrous acid form
A diazonium salts
B alcohols
C nitrosamines
D amides
Characteristic reaction of secondary amines.
Tertiary amines with nitrous acid give
A alcohol
B diazonium salt
C no reaction
D nitro compound
No replaceable hydrogen on nitrogen.
Aromatic diazonium salts are versatile intermediates because they
A are very stable
B undergo substitution reactions easily
C are strong bases
D are nucleophiles
–N₂⁺ is an excellent leaving group.
Sandmeyer reaction converts diazonium salt into
A alcohol
B phenol
C halobenzene
D aniline
Cu(I) salts replace diazonium group.
Replacement of diazonium group by –OH is done by
A Sandmeyer reaction
B Gattermann reaction
C hydrolysis
D azo coupling
Heating with water gives phenol.
Replacement of diazonium group by iodine requires
A CuI
B KI
C NaI
D I₂
Iodide ion replaces diazonium group directly.
Azo coupling reaction gives
A nitro compounds
B azo dyes
C alcohols
D phenols
Coupling with activated aromatic compounds.
Azo coupling is favoured in
A acidic medium
B basic medium
C neutral medium
D alcoholic medium
Phenoxide ion activates ring.
Aniline is protected before nitration by
A reduction
B oxidation
C acetylation
D sulphonation
Prevents excessive activation.
Acetanilide directs substitution to
A meta position
B ortho and para positions
C para only
D meta and para
–NHCOCH₃ is o,p-directing.
Which group is strongly activating in EAS
A –NO₂
B –CN
C –NH₂
D –COOH
Strong +R effect.
Nitro group is meta-directing because it
A donates electrons
B withdraws electrons by −R and −I effects
C increases steric hindrance
D stabilises σ-complex
Destabilises o,p σ-complex.
Which reaction introduces –CHO group into benzene
A Reimer–Tiemann
B Gattermann–Koch
C Friedel–Crafts alkylation
D Sandmeyer
Uses CO + HCl + AlCl₃/CuCl.
Nucleophilic aromatic substitution occurs easily when ring has
A electron-donating groups
B electron-withdrawing groups at o/p position
C alkyl groups
D amino groups
Stabilises Meisenheimer complex.
Which compound undergoes nucleophilic aromatic substitution fastest
A chlorobenzene
B bromobenzene
C nitrochlorobenzene
D toluene
–NO₂ stabilises intermediate.
Nucleophilic aromatic substitution proceeds via
A SN1
B SN2
C addition–elimination
D free radical
Meisenheimer complex formation.
Benzyne mechanism occurs under
A mild conditions
B strongly acidic conditions
C strongly basic conditions
D neutral conditions
Requires elimination of HX.
Which base is commonly used for benzyne mechanism
A NaOH
B NaNH₂
C KOH
D NH₃
Strong base in liquid ammonia.
In benzyne mechanism, substitution occurs at
A original carbon only
B adjacent carbon
C any one of two carbons
D meta position only
Benzyne is symmetrical.
Aromatic nucleophilic substitution is favoured when
A leaving group is poor
B ring is activated by EDG
C ring is activated by EWG
D solvent is non-polar
Electron withdrawal stabilises intermediate.
Which is a good leaving group in diazonium reactions
A Cl⁻
B OH⁻
C N₂
D NH₂⁻
Nitrogen gas escapes, driving reaction.
Which compound gives azo dye most readily
A benzene
B phenol
C nitrobenzene
D chlorobenzene
Activated ring couples easily.
Which reaction forms phenol from diazonium salt
A Sandmeyer
B Gattermann
C hydrolysis
D coupling
Water replaces diazonium group.
Which amine reacts fastest with HCl
A aniline
B methylamine
C nitroaniline
D diphenylamine
Strongest base among options.
Amines form salts with acids due to
A covalent bonding
B hydrogen bonding
C protonation of nitrogen
D oxidation
Lone pair accepts proton.
Which amine is least basic
A methylamine
B ammonia
C aniline
D ethylamine
Lone pair delocalised into ring.
Which compound gives carbylamine test
A secondary amine
B tertiary amine
C primary amine
D amide
Only primary amines respond.
Carbylamine test produces
A pleasant smell
B fruity smell
C foul smell
D no smell
Isocyanides have unpleasant odour.
Which reagent is used in carbylamine test
A NaOH
B chloroform
C chloroform + alcoholic KOH
D KI
Forms isocyanide.
Hinsberg test distinguishes
A alcohols
B aldehydes
C amines
D acids
Differentiates 1°, 2°, 3° amines.
In Hinsberg test, secondary amine forms
A soluble sulphonamide
B insoluble sulphonamide
C no reaction
D diazonium salt
No acidic hydrogen for salt formation.
Which amine does not react in Hinsberg test
A primary
B secondary
C tertiary
D aromatic
No N–H bond.
Which compound undergoes fastest EAS
A nitrobenzene
B benzene
C aniline
D chlorobenzene
Strong activation by –NH₂.
Which group deactivates benzene most strongly
A –CH₃
B –Cl
C –NO₂
D –OH
Strong −I and −R effects.
Which reaction preserves aromaticity
A addition
B elimination
C electrophilic substitution
D nucleophilic addition
Core reaction of aromatic compounds.
Which reagent nitrates benzene
A conc. HNO₃
B HNO₃ + H₂SO₄
C NaNO₂
D NO₂
Generates nitronium ion.
Which reaction introduces halogen into benzene ring
A free radical substitution
B nucleophilic substitution
C electrophilic substitution
D elimination
FeCl₃/AlCl₃ catalysed halogenation.
Correct statement is
A Amines are acidic compounds
B Diazotisation occurs at high temperature
C Electron-withdrawing groups favour nucleophilic aromatic substitution
D Aniline is meta-directing
They stabilise Meisenheimer complex.