Tiêu đề DPP - 2 Solutions.pdf ✅

Class : XIIth Subject : CHEMISTRY Date : DPP No. : 2 1 (b) respectively. In such case o-(minor) and p-isomers (major) predominates. 2 (c) C2H5NH2 is stronger base than NH3. The presence of alkyl group on N-atom intensifies –ve charge on N-atom and thus, electron pair is donated more readily. 3 (a) (CH3 )4N +I ― + NaOH→(CH3 )4N +OH ― + Nal (CH3 )4N +OH ―∆(CH3 )3N + CH3OH methanol 4 (c) Electron deficient group decreases the electron density of N-atom, thus, makes its lone pair less available for donation 5 (d) C6H5NH2 + CI ― COCH3NaOHC6H5NHCOCH3 + HCI aniline acetyl chloride acetanilide 6 (d) C3H9N represent following structures NHand C O gp. are o-and p-directing (activating) and m-directing gps.(deactivating) Topic :- Amines R NH2 H NH2 (+ve IE of alkyl gp.) Solutions
CH3CH2CH2NH2 Propanamine (1°amine) H | CH3CH2 ― N ― CH3 N-methyl ethanamine (2°amine) CH3 | CH3 ― N ― CH3 N,N-dimethyl methanamine (3°amine) 7 (c) Presence of α-H atom is the main condition for exhibiting tautomerism. The reactant taken in reaction (C) does not contain any α-H atom, thus the product (Y)will also show the absence of α-H atom, Hence, Y will show tautomerism 8 (a) R2NH + HNO2⟶R2N—N = O + H2O Nitrosoamines are carcinogens. 9 (b) Acetonitriles on hydrolysis produce carboxylic acids with the evolution of ammonia. O O || || CH3 ― C ≡ NH2OCH3 ― C ― NH2H2OCH3 ― C ― OH + NH3 Acetonitrile acetamide acetic acid
11 (b) Methyl cyanide gives acetic acid on hydrolysis. O || CH3CNH2O/H +CH3 ― C ― NH2H2O/H +CH3COOH + NH3 12 (c) 2RNH2 + 2HCl + PtCl4⟶(RNH3 )2PtCl6;RNH3AuCl4 13 (c) General formula for any amine is CnH2n+3N; also note that for primary amine, it is CnH2n+1 NH2; for secondary amine, it is CnH2n+2NH and for tertiary amine, it is CnH2n+3N. 14 (c) Aniline on diazotization in cold (at 0° to 5°C) gives benzene diazonium chloride. This benzene diazonium chloride on coupling reaction with dimethyl aniline gives a coloured product i.e. ,p(N, N dimethyl)amino azobenzene (azodye) 16 (c) Nitrobenzene on reduction with lithium aluminium hydride (LiAIH4) gives azobenzene. 17 (c) NH2 + NaNH2 +2 HCl 0-5 oC Diazotization N N Cl + NaCl + 2H2O benzene diazonium chloride N N N N(CH3 )2 HCl N.Cl + H N(CH3 )2 NaOH NO2 LiAlH4 2 N N nitrobenzene azobenzene
Both gives alkane (RH) with Grignard reagents RMgX due to the presence of acidic hydrogen (N—H) 19 (c) Presence of methyl group increase the electron density on nitrogen. So, increases the basicity. Aniline is weaker base than the primary aliphatic amines and this may be explained by resonance. The lone pair of N is involved in resonance, thus not available for donation. That’s why basic strength of aryl amines (aniline) is lowest. 20 (d) All primary (aliphatic ) amines give alcohol with HNO2 except CH3NH2 which forms CH3—O—N = O and CH3OCH3.