Tiêu đề DPP - 8 Solutions.pdf ✅

9 (a) Trimethyl amine is a tertiary amine. It dissolve in cold nitrous acid to form salts which decompose on warming to nitrosoamine and alcohol. It will not liberate nitrogen. (CH3 )3N + HNO2→[(CH3 )3NH] + NO ― 2 trimethyl ammonium nitrite 11 (a) Carbylamine reaction is given by aliphatic and aromatic primary amine hence, it can be used for the distinguish of primary amine with secondary and tertiary amine. In this reaction, a primary amine reacts with chloroform and alcoholic KOH to give poisonous substance isocyanide. RNH2 + CHCI3 + 3KOH(alc.)∆RNC + 3KCI + 3H2O Primary amine alkyl isocyanide 12 (b) Nitrobenzene is reduced by Zn and alcoholic KOH into hydrazobenzene. 2C6H5NO2 + 10HZn + alc.KOHC6H5 ― NH ― NH ― C6H5 + H2O hydrazobenzene 13 (b) Electron withdrawing groups (e.g., benzyl) because the basicity of amines. Electron donating groups (e.g., alkyl) increase the acidity of amines. ∴ The correct order of basicity of amines is C2H5NH2 > CH3NH2 > NH3 > C6H5NH2 14 (b) Aliphatic amines (in which amino group is attached with alkyl group) are more basic than aromatic amines (in which amino group is bonded directly with benzene nucleus). Hence, C6H5CH2NH2 (benzyl amine), being an aliphatic amine, is the most basic among the given the compounds. 15 (d) (a) C6H5CONH2LiAlH4 ether C6H5CH2NH2
Benzylamine (b) C6H5CH2CONH2 Br2/KOH C6H5CH2NH2 Benzylamine (c)C6H5CNLiAlH4C6H5CH2NH2 Benzylamine (d) C6H5CH2NC LiAlH4 C6H5CH2NHCH3 2°amine 16 (b) Biuret formed gives violet colour with CuSO4 in alkaline medium. 17 (b) CH3 ― C ≡ NReductionCH3CH2NH2HONOCH3CH2OH methyl cyanide ethanamine ethanol 1. (B) CH3CH2NH2CHCI3,KOHCH3CH2N = C 2. Ethyl isocyanide (C) 18 (d)
∴ Z is aniline 19 (a) On direct nitration of aniline, lone pair of electrons present at nitrogen atom will accept proton from the nitrating mixture to give anilium ion which is meta directing. NO2 Sn/HCl NH2 (X) aniline NaNO2 HCl, 0 oC N2Cl (Y) diazonium salt NH2 (Z) aniline NaNH2 NH2 NH3 H2SO+HNO3 anilium ion