Chapter 13 Amines

Question 1. Which of the following is a 3° amine?

(i) 1-methylcyclohexylamine

(ii) Triethylamine

(iii) tert-butylamine

(iv) N-methylaniline

Question 2. The correct IUPAC name for $CH_2=CHCH_2NHCH_3$ is

(i) Allylmethylamine

(ii) 2-amino-4-pentene

(iii) 4-aminopent-1-ene

(iv) N-methylprop-2-en-1-amine

Question 3. Amongst the following, the strongest base in aqueous medium is ____________.

(i) $CH_3NH_2$

(ii) $NCCH_2NH_2$

(iii) $(CH_3)_2NH$

(iv) $C_6H_5NHCH_3$

Question 4. Which of the following is the weakest Brönsted base?

(i)

(ii)

(iii)

(iv) $CH_3NH_2$

Question 5. Benzylamine may be alkylated as shown in the following equation :

$C_6H_5CH_2NH_2 + R—X \rightarrow C_6H_5CH_2NHR$

Which of the following alkylhalides is best suited for this reaction through $S_N1$ mechanism?

(i) $CH_3Br$

(ii) $C_6H_5Br$

(iii) $C_6H_5CH_2Br$

(iv) $C_2H_5Br$

Question 6. Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?

(i) $H_2$ (excess)/Pt

(ii) $LiAlH_4$ in ether

(iii) Fe and HCl

(iv) Sn and HCl

Question 7. In order to prepare a 1° amine from an alkyl halide with simultaneous addition of one $CH_2$ group in the carbon chain, the reagent used as source of nitrogen is ___________.

(i) Sodium amide, $NaNH_2$

(ii) Sodium azide, $NaN_3$

(iii) Potassium cyanide, KCN

(iv) Potassium phthalimide, $C_6H_4(CO)_2N^–K^+$

Question 8. The source of nitrogen in Gabriel synthesis of amines is _____________.

(i) Sodium azide, $NaN_3$

(ii) Sodium nitrite, $NaNO_2$

(iii) Potassium cyanide, KCN

(iv) Potassium phthalimide, $C_6H_4(CO)_2N^–K^+$

Question 9. Amongst the given set of reactants, the most appropriate for preparing 2° amine is _____.

(i) 2° R—Br + $NH_3$

(ii) 2° R—Br + NaCN followed by $H_2$/Pt

(iii) 1° R—$NH_2$ + RCHO followed by $H_2$/Pt

(iv) 1° R—Br (2 mol) + potassium phthalimide followed by $H_3O^+$/heat

Question 10. The best reagent for converting 2–phenylpropanamide into 2-phenylpropanamine is _____.

(i) excess $H_2$

(ii) $Br_2$ in aqueous NaOH

(iii) iodine in the presence of red phosphorus

(iv) $LiAlH_4$ in ether

Question 11. The best reagent for converting, 2-phenylpropanamide into 1- phenylethanamine is ____.

(i) excess $H_2$/Pt

(ii) $NaOH/Br_2$

(iii) $NaBH_4$/methanol

(iv) $LiAlH_4$/ether

Question 12. Hoffmann Bromamide Degradation reaction is shown by __________.

(i) $ArNH_2$

(ii) $ArCONH_2$

(iii) $ArNO_2$

(iv) $ArCH_2NH_2$

Question 13. The correct increasing order of basic strength for the following compounds is _________.

(I)

(II)

(III)

(i) II < III < I

(ii) III < I < II

(iii) III < II < I

(iv) II < I < III

Question 14. Methylamine reacts with $HNO_2$ to form _________.

(i) $CH_3—O—N=O$

(ii) $CH_3—O—CH_3$

(iii) $CH_3OH$

(iv) $CH_3CHO$

Question 15. The gas evolved when methylamine reacts with nitrous acid is __________.

(i) $NH_3$

(ii) $N_2$

(iii) $H_2$

(iv) $C_2H_6$

Question 16. In the nitration of benzene using a mixture of conc. $H_2SO_4$ and conc. $HNO_3$, the species which initiates the reaction is __________.

(i) $NO_2$

(ii) $NO^+$

(iii) $NO_2^+$

(iv) $NO_2^-$

Question 17. Reduction of aromatic nitro compounds using Fe and HCl gives __________.

(i) aromatic oxime

(ii) aromatic hydrocarbon

(iii) aromatic primary amine

(iv) aromatic amide

Question 18. The most reactive amine towards dilute hydrochloric acid is ___________.

(i) $CH_3—NH_2$

(ii)

(iii)

(iv)

Question 19. Acid anhydrides on reaction with primary amines give ____________.

(i) amide

(ii) imide

(iii) secondary amine

(iv) imine

Question 20. The reaction $ArN_2^+Cl^– \xrightarrow{Cu/HCl} ArCl + N_2 + CuCl$ is named as _________.

(i) Sandmeyer reaction

(ii) Gatterman reaction

(iii) Claisen reaction

(iv) Carbylamine reaction

Question 21. Best method for preparing primary amines from alkyl halides without changing the number of carbon atoms in the chain is

(i) Hoffmann Bromamide reaction

(ii) Gabriel phthalimide synthesis

(iii) Sandmeyer reaction

(iv) Reaction with $NH_3$

Question 22. Which of the following compound will not undergo azo coupling reaction with benzene diazonium chloride.

(i) Aniline

(ii) Phenol

(iii) Anisole

(iv) Nitrobenzene

Question 23. Which of the following compounds is the weakest Brönsted base?

(i)

(ii)

(iii)

(iv)

Question 24. Among the following amines, the strongest Brönsted base is __________.

(i)

(ii) $NH_3$

(iii)

(iv)

Question 25. The correct decreasing order of basic strength of the following species is _______.

$H_2O, NH_3, OH^–, NH_2^–$

(i) $NH_2^– > OH^– > NH_3 > H_2O$

(ii) $OH^– > NH_2^– > H_2O > NH_3$

(iii) $NH_3 > H_2O > NH_2^– > OH^–$

(iv) $H_2O > NH_3 > OH^– > NH_2^–$

Question 26. Which of the following should be most volatile?

(I) $CH_3CH_2CH_2NH_2$

(II) $(CH_3)_3N$

(III)

(IV) $CH_3CH_2CH_3$

(i) II

(ii) IV

(iii) I

(iv) III

Question 27. Which of the following methods of preparation of amines will give same number of carbon atoms in the chain of amines as in the reactant?

(i) Reaction of nitrite with $LiAlH_4$.

(ii) Reaction of amide with $LiAlH_4$ followed by treatment with water.

(iii) Heating alkylhalide with potassium salt of phthalimide followed by hydrolysis.

(iv) Treatment of amide with bromine in aqueous solution of sodium hydroxide.

Question 28. Which of the following cannot be prepared by Sandmeyer’s reaction?

(i) Chlorobenzene

(ii) Bromobenzene

(iii) Iodobenzene

(iv) Fluorobenzene

Question 29. Reduction of nitrobenzene by which of the following reagent gives aniline?

(i) Sn/HCl

(ii) Fe/HCl

(iii) $H_2$-Pd

(iv) $Sn/NH_4OH$

Question 30. Which of the following species are involved in the carbylamine test?

(i) R—NC

(ii) $CHCl_3$

(iii) $COCl_2$

(iv) $NaNO_2 + HCl$

Question 31. The reagents that can be used to convert benzenediazonium chloride to benzene are __________.

(i) $SnCl_2/HCl$

(ii) $CH_3CH_2OH$

(iii) $H_3PO_2$

(iv) $LiAlH_4$

Question 32. The product of the following reaction is __________.

(i)

(ii)

(iii)

(iv)

Question 33. Arenium ion involved in the bromination of aniline is __________.

(i)

(ii)

(iii)

(iv)

Question 34. Which of the following amines can be prepared by Gabriel synthesis.

(i) Isobutyl amine

(ii) 2-Phenylethylamine

(iii) N-methylbenzylamine

(iv) Aniline

Question 35. Which of the following reactions are correct?

(i)

(ii)

(iii)

(iv)

Question 36. Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?

(i) Acetyl chloride/pyridine followed by reaction with conc. $H_2SO_4$ + conc. $HNO_3$.

(ii) Acetic anyhdride/pyridine followed by conc. $H_2SO_4$ + conc. $HNO_3$.

(iii) Dil. HCl followed by reaction with conc. $H_2SO_4$ + conc. $HNO_3$.

(iv) Reaction with conc. $HNO_3$ + conc.$H_2SO_4$.

Question 37. Which of the following reactions belong to electrophilic aromatic substitution?

(i) Bromination of acetanilide

(ii) Coupling reaction of aryldiazonium salts

(iii) Diazotisation of aniline

(iv) Acylation of aniline

Question 38. What is the role of $HNO_3$ in the nitrating mixture used for nitration of benzene?

Question 39. Why is $NH_2$ group of aniline acetylated before carrying out nitration?

Question 40. What is the product when $C_6H_5CH_2NH_2$ reacts with $HNO_2$?

Question 41. What is the best reagent to convert nitrile to primary amine?

Question 42. Give the structure of ‘A’ in the following reaction.

Question 43. What is Hinsberg reagent?

Question 44. Why is benzene diazonium chloride not stored and is used immediately after its preparation?

Question 45. Why does acetylation of $—NH_2$ group of aniline reduce its activating effect?

Question 46. Explain why $MeNH_2$ is stronger base than MeOH?

Question 47. What is the role of pyridine in the acylation reaction of amines?

Question 48. Under what reaction conditions (acidic/basic), the coupling reaction of aryldiazonium chloride with aniline is carried out?

Question 49. Predict the product of reaction of aniline with bromine in non-polar solvent such as $CS_2$.

Question 50. Arrange the following compounds in increasing order of dipole moment.

$CH_3CH_2CH_3, CH_3CH_2NH_2, CH_3CH_2OH$

Question 51. What is the structure and IUPAC name of the compound, allyl amine?

Question 52. Write down the IUPAC name of

Question 53. A compound Z with molecular formula $C_3H_9N$ reacts with $C_6H_5SO_2Cl$ to give a solid, insoluble in alkali. Identify Z.

Question 54. A primary amine, $RNH_2$ can be reacted with $CH_3—X$ to get secondary amine, $R—NHCH_3$ but the only disadvantage is that 3° amine and quaternary ammonium salts are also obtained as side products. Can you suggest a method where $RNH_2$ forms only 2° amine?

Question 55. Complete the following reaction.

Question 56. Why is aniline soluble in aqueous HCl?

Question 57. Suggest a route by which the following conversion can be accomplished.

Question 58. Identify A and B in the following reaction.

Question 59. How will you carry out the following conversions?

(i) toluene $\rightarrow$ p-toluidine

(ii) p-toluidine diazonium chloride $\rightarrow$ p-toluic acid

Question 60. Write following conversions:

(i) nitrobenzene $\rightarrow$ acetanilide

(ii) acetanilide $\rightarrow$ p-nitroaniline

Question 61. A solution contains 1 g mol. each of p-toluene diazonium chloride and pnitrophenyl diazonium chloride. To this 1 g mol. of alkaline solution of phenol is added. Predict the major product. Explain your answer.

Question 62. How will you bring out the following conversion?

Question 63. How will you carry out the following conversion?

$\xrightarrow{NH_2} NO_2$

Question 64. How will you carry out the following conversion?

$\xrightarrow{NH_2} Br$

Question 65. How will you carry out the following conversions?

(i)

(ii)

Question 66. Match the reactions given in Column I with the statements given in Column II.

Question 67. Match the compounds given in Column I with the items given in Column II.

Question 68. Assertion : Acylation of amines gives a monosubstituted product whereas alkylation of amines gives polysubstituted product.

Reason : Acyl group sterically hinders the approach of further acyl groups.

Question 69. Assertion : Hoffmann’s bromamide reaction is given by primary amines.

Reason : Primary amines are more basic than secondary amines.

Question 70. Assertion : N-Ethylbenzene sulphonamide is soluble in alkali.

Reason : Hydrogen attached to nitrogen in sulphonamide is strongly acidic.

Question 71. Assertion : N, N-Diethylbenzene sulphonamide is insoluble in alkali.

Reason : Sulphonyl group attached to nitrogen atom is strong electron withdrawing group.

Question 72. Assertion : Only a small amount of HCl is required in the reduction of nitro compounds with iron scrap and HCl in the presence of steam.

Reason : $FeCl_2$ formed gets hydrolysed to release HCl during the reaction.

Question 73. Assertion : Aromatic 1° amines can be prepared by Gabriel Phthalimide Synthesis.

Reason : Aryl halides undergo nucleophilic substitution with anion formed by phthalimide.

Question 74. Assertion : Acetanilide is less basic than aniline.

Reason : Acetylation of aniline results in decrease of electron density on nitrogen.

Question 75. A hydrocarbon ‘A’, ($C_4H_8$) on reaction with HCl gives a compound ‘B’, ($C_4H_9Cl$), which on reaction with 1 mol of $NH_3$ gives compound ‘C’, ($C_4H_{11}N$). On reacting with $NaNO_2$ and HCl followed by treatment with water, compound ‘C’ yields an optically active alcohol, ‘D’. Ozonolysis of ‘A’ gives 2 mols of acetaldehyde. Identify compounds ‘A’ to ‘D’. Explain the reactions involved.

Question 76. A colourless substance ‘A’ ($C_6H_7N$) is sparingly soluble in water and gives a water soluble compound ‘B’ on treating with mineral acid. On reacting with $CHCl_3$ and alcoholic potash ‘A’ produces an obnoxious smell due to the formation of compound ‘C’. Reaction of ‘A’ with benzenesulphonyl chloride gives compound ‘D’ which is soluble in alkali. With $NaNO_2$ and HCl, ‘A’ forms compound ‘E’ which reacts with phenol in alkaline medium to give an orange dye ‘F’. Identify compounds ‘A’ to ‘F’.

Question 77. Predict the reagent or the product in the following reaction sequence.