Compounds Containing Nitrogen — CBSE Class 12 board PYQs

The correct name of the given reaction is

Amides can be converted into amines by the reaction named:

Which of the following would not be a good choice for reducing nitrobenzene to aniline?

Out of the following, the strongest base in aqueous solution is:

Arrange the following in increasing order of boiling points: (CH₃)₃N, C₂H₅OH, C₂H₅NH₂.

Write the IUPAC name of the compound shown in the figure (CH₃–NH–CH(CH₃)₂).

Write the IUPAC name of the compound shown in the figure (2,4,6-tribromoaniline).

Give a chemical test to distinguish between ethylamine and aniline.

Rearrange the following in increasing order of their basic strengths: C₆H₅NH₂, C₆H₅N(CH₃)₂, (C₆H₅)₂NH and CH₃NH₂.

Why is an alkylamine more basic than ammonia?

Write a chemical reaction in which the iodide ion replaces the diazonium group in a diazonium salt.

Rearrange the following in increasing order of their basic strengths: aniline, p-nitroaniline, p-toluidine.

Arrange the following compounds in increasing order of basic strength in their aqueous solutions: NH₃, CH₃NH₂, (CH₃)₂NH, (CH₃)₃N.

Write the chemical equation for the preparation of a primary amine from a primary alkyl halide.

Mention one commercial use of N,N-dimethylaniline.

Why do amines react as nucleophiles?

How is m-nitroaniline obtained from nitrobenzene?

Why are aqueous solutions of amines basic in nature?

Give a chemical test to distinguish between a primary and a secondary amine.

Give a chemical test to distinguish between aniline and N-methylaniline.

How is aminoethane obtained from ethanal (acetaldehyde)?

How is aniline obtained from benzoic acid?

How is the basic strength of aromatic amines affected by the presence of an electron-releasing group on the benzene ring?

Why do primary amines have higher boiling points than tertiary amines?

State the reaction taking place when bromine water is added to an aqueous solution of aniline.

Arrange the following in order of increasing basic character in aqueous solution: NH₃, EtNH₂, Et₂NH, Et₃N.

Write the IUPAC name of the compound shown in the figure (CH₃O–C₆H₄–NH₂, para).

Write the IUPAC name of the compound shown in the figure (per the printed structure).

Write the IUPAC name of the following compound: C₆H₅N⁺(CH₃)₃Br⁻.

Give a chemical test to distinguish between the following pair of compounds: CH₃CH₂NH₂ and (CH₃)₂NH.

Illustrate the following with an example: acetylation reaction.

How is Orange-I prepared?

Complete the reaction shown in the figure (a diazonium salt with the printed coupling partner).

a) Write the IUPAC name of the compound shown in the figure (per the printed structure).
b) How is phenylaminomethane obtained from phenyl nitrile (benzonitrile)?

Write one chemical reaction for the carbylamine test.

Out of methylamine and aniline, which is the stronger base, and why?

Account for the following: aniline is a weaker base than cyclohexylamine.

Write the IUPAC name of the compound shown in the figure (CH₃CH₂CH₂–N(CH₃)₂).

Write the chemical reactions occurring in the preparation of fluorobenzene from aniline.

Identify A and B in the following sequence:

What does the K_b value for an amine stand for?

For an amine RNH₂, write the expression for K_b to indicate its base strength.

Account for the following: ammonolysis of an alkyl halide does not give the corresponding amine in a pure state.

(a) Carry out the following conversions:
(i) nitrobenzene to aniline
(ii) aniline to phenol

(b)(i) Write a chemical test to distinguish between dimethylamine and ethanamine.
(ii) Write the product formed when benzenediazonium chloride is treated with KI.

A compound 'X' with molecular formula C₃H₉N reacts with C₆H₅SO₂Cl to give a solid insoluble in alkali. Identify 'X' and give the IUPAC name of the product. Write the reaction involved.

(a)(i) Draw the zwitterion structure of sulphanilic acid.
(ii) How can the activating effect of the –NH₂ group in aniline be controlled?

(b)(i) Complete the reaction shown in the figure with the main product formed.
(ii) Convert bromoethane to propanamine.

A primary amine 'A', C₂H₇N, reacts with an alkyl halide (C₂H₅I) to give a secondary amine 'B'. 'B' reacts with C₆H₅SO₂Cl to give a solid 'C' which is insoluble in alkali. Identify A, B and C and write all the chemical reactions involved.

a) Account for the following:
i) pK_b for aniline is more than that of methylamine.
ii) Aniline does not undergo Friedel–Crafts reactions.
iii) Primary amines have higher boiling points than tertiary amines.

b)
i) Arrange the following in increasing order of basic strength in aqueous solution: CH₃NH₂, (CH₃)₃N, (CH₃)₂NH.
ii) What is Hinsberg's reagent?
iii) What is the role of pyridine in the acylation reaction of amines?

Give the structures of A and B in the following sequences:
(a) CH₃COOH →NH₃, Δ→ A →NaOBr→ B
(b) C₆H₅NO₂ →Fe/HCl→ A →NaNO₂ + HCl, 0–5 °C→ B
(c) C₆H₅N₂⁺Cl⁻ →CuCN, Δ→ A →H₂O/H⁺→ B

(a) How will you distinguish between the following pairs of compounds?
(i) aniline and ethanamine
(ii) aniline and N-methylaniline
(b) Arrange the following compounds in decreasing order of their boiling points: butanol, butanamine, butane.

An aromatic compound 'A' on heating with Br₂ and KOH forms compound 'B' of molecular formula C₆H₇N, which on reacting with CHCl₃ and alcoholic KOH produces a foul-smelling compound 'C'. Write the structures and IUPAC names of compounds A, B and C.

Give reasons for the following:
(a) Acetylation of aniline reduces its activating effect.
(b) CH₃NH₂ is more basic than C₆H₅NH₂.
(c) Although –NH₂ is an o/p-directing group, aniline on nitration gives a significant amount of m-nitroaniline.

Write the structures of A, B and C in the following reactions:
i) C₆H₅COO⁻NH₄⁺ →Δ→ A →Br₂/KOH→ B →CH₃COCl/pyridine→ C
ii) C₆H₅N₂⁺BF₄⁻ →NaNO₂/Cu, Δ→ A →Sn/HCl→ B →CHCl₃ + alc. KOH→ C

Write the structures of A, B and C in the following:
i) C₆H₅CONH₂ →Br₂/aq. KOH→ A →NaNO₂ + HCl, 0–5 °C→ B →KI→ C
ii) CH₃Cl →KCN→ A →LiAlH₄→ B →CHCl₃ + alc. KOH, Δ→ C

State reasons for the following:
i) The pK_b value of aniline is more than that of methylamine.
ii) Ethylamine is soluble in water whereas aniline is not.
iii) Primary amines have higher boiling points than tertiary amines.

a) Explain why an alkylamine is more basic than ammonia.
b) How would you convert:
i) aniline to nitrobenzene
ii) aniline to iodobenzene?

Give chemical tests to distinguish between the following pairs of compounds:
i) ethylamine and aniline
ii) aniline and benzylamine

Identify A and B in each of the following processes:
i) CH₃CH₂Cl →NaCN→ A →reduction Ni/H₂→ B
ii) C₆H₅NH₂ →NaNO₂/HCl→ A →C₆H₅NH₂, OH⁻→ B

Rearrange the compounds as directed:
i) increasing basic strength: C₆H₅NH₂, C₆H₅N(CH₃)₂, (C₂H₅)₂NH and CH₃NH₂
ii) decreasing basic strength: aniline, p-nitroaniline and p-toluidine
iii) increasing pK_b values: C₂H₅NH₂, C₆H₅N(CH₃)₂, (C₂H₅)₂NH and C₆H₅NH₂

Complete the following reaction equations:
i) (the diazonium reaction shown in the figure)
ii) C₆H₅N₂Cl + H₃PO₂ + H₂O →
iii) C₆H₅NH₂ + Br₂(aq) →

Giving an example of each, describe the following reactions:
i) Hofmann's bromamide reaction
ii) Gattermann reaction
iii) a coupling reaction

Complete the following reactions:
(i) C${}_6$H${}_5$N${}_2$Cl + KI →
(ii) (the reaction shown in the figure)

i) Arrange the following in increasing order of basic strength in water: C₆H₅NH₂, (C₂H₅)₂NH, (C₂H₅)₃N and NH₃.
ii) Arrange the following in increasing order of basic strength in the gas phase: C₂H₅NH₂, (C₂H₅)₂NH, (C₂H₅)₃N and CH₃NH₂.

Write one chemical reaction each to illustrate the following:
i) Hofmann bromamide reaction
ii) Gabriel phthalimide reaction

Account for the following observations:
i) pK_b for aniline is more than that for methylamine.
ii) A methylamine solution in water reacts with ferric chloride solution to give a precipitate of ferric hydroxide.
iii) Aniline does not undergo Friedel–Crafts reactions.

State the reactions and conditions for the following conversions:
i) benzenediazonium chloride to nitrobenzene
ii) aniline to benzenediazonium chloride
iii) ethanamide to methylamine

Account for any two of the following:
a) Amines are basic substances while amides are neutral.
b) Aromatic amines are weaker bases than aliphatic amines.

How would you achieve the following conversions? Write the chemical equation with reaction conditions in each case.
i) nitrobenzene to aniline
ii) an alkyl halide to a quaternary ammonium salt
iii) aniline to benzonitrile

a) Explain the following observations:
i) Electrophilic substitution in aromatic amines takes place more readily than in benzene.
ii) Primary amines boil higher than comparable tertiary amines.
b) Mention two important uses of N,N-dimethylaniline.

Give reasons:
a) Methylamine in water reacts with ferric chloride to precipitate ferric hydroxide.
b) Aromatic amines are less basic than aliphatic amines.

a) How will you convert an alkyl halide to a primary amine whose molecule has one more carbon atom than the alkyl halide used?
b) Why are amines more basic than comparable alcohols?

a) Assign a reason: alkylamines are stronger bases than arylamines.
b) How would you convert methylamine into ethylamine?

Give reasons:
a) Methylamine is a stronger base than ammonia.
b) The reactivity of the –NH₂ group is reduced in acetanilide.

i) Stating the necessary reaction conditions, write chemical equations to obtain chlorobenzene from aniline.
ii) Identify A and B in the two sequences shown in the figure.

Give reasons for the following observations:
i) It is difficult to prepare pure amines by ammonolysis of alkyl halides.
ii) Electrophilic substitution in aromatic amines takes place more readily than in benzene.

Explain the following observations:
i) In aqueous solution the K_b order is Et₂NH > Et₃N > EtNH₂.
ii) Amines are more basic than comparable alcohols.

What happens when (write reactions only):
i) nitroethane is treated with LiAlH₄
ii) a diazonium chloride reacts with phenol in basic medium

Identify A and B in the following reactions:
i) C₂H₅C≡N →LiAlH₄→ A →HNO₂→ B
ii) (the sequence shown in the figure)

Illustrate the following with an example reaction in each case:
i) Sandmeyer reaction
ii) coupling reaction

Illustrate the following with an example reaction:
i) ambident nucleophile
ii) Hinsberg test

Write one chemical equation each to exemplify the following reactions:
i) carbylamine reaction
ii) Hofmann bromamide reaction

Identify A and B in each of the three reaction sequences shown in the figure.

State the reactions for obtaining benzoic acid from aniline.

Write chemical reaction equations, one example each, for the following:
(a) a coupling reaction
(b) Hofmann's bromamide reaction
(c) acetylation

Illustrate each of the following with an example reaction:
i) Sandmeyer reaction
ii) diazotisation reaction

Give reasons for the following: sulphanilic acid is insoluble in water but is soluble in both aqueous bases and aqueous mineral acids taken separately.

Write the reactions involved in obtaining p-aminoazobenzene using only nitrobenzene as the organic starting reagent.

Account for the following observations:
i) Silver chloride dissolves in aqueous methylamine solution.
ii) Tertiary amines do not undergo acylation.
iii) Aniline reacts readily with bromine to give 2,4,6-tribromoaniline.

Write the IUPAC names of the following compounds:
i) H₂N–CH₂–CH₂–CH=CH–CHO
ii) (the amino-benzaldehyde shown in the figure)

Before reacting aniline with HNO₃ for nitration, it is converted to acetanilide. Why is this done, and how is nitroaniline obtained subsequently?

Write the IUPAC names of the two compounds shown in the figure:
i) CH₃CH(NH₂)CH(CH₃)CONH₂
ii) (CH₃)₂N–C₆H₄–NO₂ (para)

Account for the following:
i) Aniline is a weaker base than methylamine.
ii) Aryl cyanides cannot be formed by the reaction of aryl halides with sodium cyanide.

Show how p-aminoazobenzene can be obtained from aniline.

Write the chemical equations for the following conversions:
i) ethyl isocyanide from ethylamine
ii) aniline to N-phenylethanamide

(a) Illustrate Sandmeyer's reaction with an equation.
(b) Explain why (CH₃)₂NH is more basic than (CH₃)₃N in aqueous solution.

(a) Write the reactions involved in the following:
(i) Hofmann bromamide degradation
(ii) diazotisation
(iii) Gabriel phthalimide synthesis
(b) Give reasons:
(i) (CH₃)₂NH is more basic than (CH₃)₃N in aqueous solution.
(ii) Aromatic diazonium salts are more stable than aliphatic …

An aromatic compound 'A' of molecular formula C₇H₇ON undergoes the series of reactions shown in the figure. Write the structures of A, B, C, D and E.

a) Write the structures of the main products when aniline reacts with the following reagents:
i) Br₂ water ii) HCl iii) (CH₃CO)₂O/pyridine
b) Arrange the following in increasing order of boiling point: C₂H₅NH₂, C₂H₅OH, (CH₃)₃N.
c) Give a simple chemical test to distinguish betwee …