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CBSE Important Questions

CBSE Guess > Papers > Important Questions > Class XII > 2013 > Chemistry > Amines by Mr. R. Srinivas Vasudevamurthy

CBSE CLASS XII

Amines - 4 Marks Questions

1. Give one example each of the following named reactions:

a) Sand meyer reaction

b) Gabriel pthalimide synthesis.

C) Coupling reaction

d) Diazotisation reaction.

e) Gatterman reaction

f) Hoffmann bromamide reaction

2. Explain the following tests with suitable examples:

a) Carbylamine test

b) Hinsberg test.

3. Account for the following:

a) Methyl chloride reacts with AgNO2 to give nitro methane as a major product where as it gives nitrito methane as a major product with KNO2

b) C-N bond in aniline is shorter than in aliphatic amines.

c) In ammonalysis of halo alkane , primary amine is the only product when large excess of ammonia is used while quaternary ammonium salt is the only product when halo alkane is in excess.

d) Primary and sec amines have higher boiling point than tert amine.

e) Amines have lower boiling point than alcohol of comparable molar mass.

f) Amines are soluble in water. Solubility of amines p.amines>sec amines>tert amines

g) Amines are less soluble in water than alcohol.

h) Basicity of amines in aqueous solution is sec amine>tert amine>p.amine.

i) Basicity of amines in vapor phase tert amine>sec amine>p.amine.

j) Aniline is a weaker base than aliphatic amine.

k) Electron repelling group at ortho and para position increases the basicity while electron with drawing group at ortho and para position decreases the density of aniline.

l) Ammonalysis of halo alkane is carried out in the presence of a base.

m) Unlike alkylation of amines acylation stops after first styep.

n) Tert amines do not react with acid derivatives.

o) Aniline undergoes bromination even in the absence of halogen carrier.

p) Nitration of aniline gives 47% meta nitro aniline.

q) P-toluidine is more basic than aniline.

r) Amines are less acidic than alcohol.

s) Halo alkane reacts with KCN to give alkyl cyanide as a major product while it gives alkyl isocyanide as a major product with AgCN.

t) Aniline do not undergo Friedel craft's reaction.

u) Aniline can't be prepared by Gabriel pthalimide synthesis.

v) ArN2X is more stable than RN2X at lower temperature.

w) Aniline is a weaker base than ammonia.

x) Order of basicity (C2H5)2NH>(C2H5)3N > C2H5NH2>NH3

y) Order of basicity (CH3)2NH>CH3NH2>(CH3)3N>NH3

Z) Bromination of aniline after acylation gives only para bromo aniline.

aa) Sandmeyer reaction is prefered over Gatterman reaction to prepare halo arenes from aniline.

bb) Ethyl amine is soluble in water but not aniline.

cc) Aqueous solution of methyl amine with ferric chloride solution gives brown precipitate of ferric hydroxide..

dd) Gabriel pthalimide synthesis is prefered to prepare primary amine.

ee) p-nitro aniline is less basic than aniline.

4. Carry out the following conversions:

a) Ethanoyl chloride to

i) ethanamine.
ii)
N-methyl amino ethane.

b) Ethanoyl chloride methanamide

c) Methanamine to

i) N-methyl ethanamide.
ii) methyl iso cyanide.

d) Dimethyl amine to N,N dimethyl amine.

e) Ethane nitrle to

i) ethanoic acid.
ii) methyl ethanoate.
iii) acetone.
iv) ethanamine.

f) Benzo nitrile to

i) benzoic acid
ii) aniline

g) Aniline to

i) chloro benzene.

ii) bromo benzene.

iii) flouro benzene

iv) iodo benzene .

v) phenol

vi) benzene.

vii) benzoic acid.

viii) para hydroxyl azo benzene.

ix) para amino azo benzene.

x) Nitro benzene

xi) 1,3,5-tribromo benzene

xii) p-bromo aniline

xii) 2,4,6-tribromo aniline

xiii) benzyl alcohol

h) 4-nitro toluene to 2-bromo benzoic acid.

i) 3-methyl aniline to 3-nitro toluene.

j) Ethanoic acid to

a) ethanamine
b) methanamine

k) Methanol to ethanoic acid.

l) Ethanamine to methanamine

m) Methanamine to ethanamine.

n) Nitro methane to dimethyl amine.

o) Propanoic acid to ethanoic acid.

p) Ethanoic acid to propanoic acid.

q) Nitro benzene to benzoic acid.

r) Benzene to m-bromo phenol.

s) Benzoic acid to aniline.

t) Aniline to 2,4,6- tribromo fluorobenzene

u) Benzyl chloride to 2-phenyl ethanamine.

v) Chloro benzene to p-chloro aniline.

w) Benzamide to toluene

6. Distinguish chemically between

a) Methyl amine and aniline

b) methyl amine and dimethyl amine.

c) Aniline and benzyl amine

d) Aniline and N- methyl aniline.

e) dimethyl amine and trimethyl amine.

7. An organic compound

A on reaction with NaOH and Br2 gives

B. B on diazotization gives

C. C when warmed with water gives

D. D gives violet coloration with neutral ferric chloride solution. Identify the compounds and write the equations of the reactions involved.

8. Give equation for the following reactions:

a) ethanolic NH3 with C2H5Cl

b) ammonalysis of benzyl chloride followed by reaction with 2 moles of methyl chloride.

c) sulphonation of aniline

d) reaction of aniline with acetic anhydride.

e) reaction of aniline with aqueous bromine.

9. Give the structure of A,B and C in the following reactions:

                    NaCN               OH-                 NaOH
a) C2H5   B 
                                           partial                     Br2
                                           hydrolysis

 

                             CuCN               H3O+             NH3
b) C6H5N2Cl  A   C   


c) C2H5Br +KCN  C
                                                           LiAlH4            HNO2, 273K

 

d)  C6H5NO2 B C
                          Fe/HCl        NaNO2+HCl         H3O+


                                                       273K
e)  CH3COOH+NH3 A B C
                                        Heat             NaOBr          NaNO2+HCl, 273K


    
f) C6H5NO2 A B C
                       Fe/HCl      NaNO2+HCl, 273K          C6H5OH

10. An organic compound A on heating with aqueous ammonia forms B. B on treatment with Br2 and KOH gives C of molecular formula C6H7N. Give the structure of the compounds A,B and C. Write IUPAC name of the each compound.

11. Give the equations of the reactions involved when  aniline is reacted with

a) CHCl3+KOH 

b) Conc sulphuric acid

c) aqueous bromine

d) acetic anhydride

12.  Give the equation of the reaction involved when benzene diazonium chloride is treated with

a) H3PO2+ H2O

b) i) HBF4 followed by NaNO2 / Cu D

13. Arrange the following:

a) increasing order of pKb values- C2H5NH2, (C2H5)2NH, C6H5NHCH3, C6H5NH2

b) increasing order of basic strength

(i) C6H5NH2, C6H5N(CH3)2, (C2H5)2NH,CH3NH2

(ii)  Aniline, para nitro aniline, para toluidine

(iii)  Aniline, N-Methyl aniline, benzyl amine

(iv)  Aniline, methyl amine, dimethyl amine, trimethyl amine, benzyl amine

(iv)  Aniline, ethyl amine, diethyl amine, triethyl amine.

c) decreasing order of basic strength in gas phase C2H5NH2, (C2H5)2NH, (C2H5)3N, NH3

d) increasing order of boiling point- C2H5OH, (CH3)2NH,C2H5NH2

e) increasing order of solubility in water- Aniline, ethyl amine, Diethyl amine

14. Write the reaction of final alkylation product with excess of ethyl iodide in the presence of Sodium carbonate solution.

15. Write the chemical reaction of aniline with benzoyl chloride and give the IUPAC name of the product formed.

 

Submitted By : Mr. R. Srinivas Vasudevamurthy
Email: vasudm@yahoo.co.uk