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The Learning App For, IAM NEET JEE JET RAS, , , , , , , , 20 || Some Basic Principles of Organic Chemistry, , , , , , , , , , e Tetravalency of carbon hybridization and shape of molecules, , + In excited state electonic configuration of c-atom has four unpaired electrons, hence carbon can, form four covalent bonds., , + Formation of same number of orbitals having same properties of various type of orbitals (s and, p) of C-atom is called hybridization and orbitals produces are called hybridized orbitals., , + Hybrid orbitals of carbon form o- bond and those orbitals which do not take part in hybridisation, form pi () bond., , + Single bond is always 6 bond. In double bond one o and one 1 bonds are present, while in triple, bond one o and two 7 bonds are present., , + On the basis of number of o-bond in carbon atom its hybridization is determined., , @ Remember :, , , , , , , , , , , , , , , , , , , , , , , , , , , , Type of Type of hybridi shape of bond Cc-C, compound bond -zation of molecule angle bond length, carbon, tod, Alkane «& - ¢ - sp> tetrahedral 109° 28° 154 pm, Alkene >C = C< sp? trigonal plannar 120° 134 pm, Alkyne -C =C sp linear 180° 120 pm, 1. In which of the following molecule carbon-carbon bond length is least ?, (A) ethane (B) ethene (C) ethyne (D) benzene, 2. How many o and x bonds are present in dicyano ethene CN — CH = CH — CN, respectively ?, (A) 7 and 1 (B) 7 and 5 (C) 5 and 7 (D) 3 and 5, Sy In but-l-ene-3-yne number of o and x bonds are ...... respectively., (A) 7 and 5 (B) 7 and 3 (C) 6 and 4 (D) 6 and 3, 4. In which of the following compound all C-atom have sp? hybridization ?, (A) ethane (B) propene (C) ethyne (D) ethylene, 5. What is the type of hybridization of each C in the following compound ?, , CH, - CH = CH - CN, (A) sp, sp*, sp, sp (B) sp*, sp*, sp’, sp (C) sp, sp’, sp’, sp (D)_ sp’, sp’, sp’, sp, , 6. What is the expected bond angle in the molecule in which the central atom is sp* hybridized ?, (A) 109° 28° (B) 120° (C) 90° (D) 180°, 7. Which hybrid orbitals are involved in the bond formation between C, — C, in given organic, , compound ?, , 'CH = *C — 3CH, — *CH,, , (A) sp— sp (B) sp’— sp (C) sp’ — sp* (D) sp sp, 475

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OT veer sce ser ras, , 10., , , , P.O,, In the dehydration reaction CH,CONH, => CH.CN hybridization of carbonyl carbon changes, , to what ?, , (A) sp* to sp? (B) sp? to sp* (C) sp? to sp (D) sp to sp*, , What are the changes in hybridization of carbon in addition halogenation reaction of ethene ?, (A) sp? to sp? (B) sp? to sp* (C) sp? to sp? (D) sp to sp*, , What is the correct order of C-C bond length ?, , (A) C,H, > C,H, > C,H, (B) C,H, > CH, > C\H,, , (© CH, < CH, < CH,, , , , , , , , ‘Answers : 1. (C), 2. (B), 3. (B), 4. (D), 5. (B), 6. (A), 7. (D), 8. (©), 9. (B), 10. (A), , , , , , © Classification of organic compounds on the basis of functional group, , e The atom or group of atom which is responsible for characteristic reactions of organic compunds, is called functional group., , e While writing the structure of organic compounds it is necessary to remember the number of, bonds. For example carbon has four bonds, nitrogen has three bonds, oxygen has two bond and, for hydrogen and halogen single bond., , e While writing the name of organic compounds on the basis of number of C atom present in it, corresponding word root (Greekword) is used which as follows :, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Number of C > 1 2 3 4 5 6 a 8 9 10, word root > meth eth prop but pent hex hept oct non dec, e Organic compounds classified into 14 parts based on functional group :, Type of Functional Prefix/suffix Example IUPAC, compound group in nomenclature Name, (1) Alkane ¢ - ¢ - —| ane CH,-CH,-CH, propane, R-H, (2) Alkene >C=C< -| ene CH,-CH=CH, propene, (3) Alkyne —C=C-— —| yne CH,-C=CH propyne, (4) Alcohol —OH -| ol CH,-CH,-CH,-OH propan-|-ol, (5) Ether 26 alkoxy |- CH,-O-CH,-CH, | Methoxy ethane, (6) Aldehyde -CHO -| al CH,-CH,-CHO propanal, (7) Ketone -CO- -| one CH,-CO-CH, propanone, (8) Carboxylic -COOH -| oic CH, CH,-COOH propanoic, acid acid acid, (9) Ester —COOR -| oate CH, COOCH, Methyl, R=alkyl ethanoate, (10) Amine (a) —-NH, —| amine CH,-CH,-CH,-NH, propan-1, primary amine -amine, , , , , , , , , , , , , , , , , , 476

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The Learning App For, IAM NEET JEE JET RAS, , , , , , , , , , , , , , , , , , , , , , , , , , , , Amine (b) —NH— —| amine CH,-CH,-NH-CH, N-Methyl, secondary amine ethanamine, Amine (c) <N- —| amine CH,-CH,-N-CH, | N,N-dimethyl, tertiary amine cH, ethanamine, (11) Amide —-CONH, —| amide CH,CH,CONH, Propananide, (12) Nitro -NO, Nitro |- CH,-CH,-CH,-NO, | I-nitro propane, (13) Cyanide -CN — nitrile CH,-CH,-CN propane nitrile, (14) Halide =X halo |- CH-CH,-CH,-Cl_|I-chloro propane], X=F, Cl, Br, I, Note :, , (1) In alkane, alkene and alkyne’s nomenclature proper suffix is added to wordroot on the basis of, number of carbon, eg., CH, — CH = CH, word root + suffix, prop + ene = propene, (2) In other compounds nomenclature appropriate prefix or suffix is added to alkane name., eg., CH,- CH — CH, prefix + alkane, 2 - chloro + propane, SI = 2 - chloro propane, (3) In case of ether, group with less number of carbon atom attached to oxygen is given, prefix alkoxy and group with greater number of carbon is taken as alkane., (4) In ester (-COOR), after writing the name of alkyl group connected in place of R,, remaining carbon is taken as alkane and “oate” suffix is added., (5) In 2° and 3° amine, group with highest number of carbon is taken as alkane, suffix, “amine” is added and remaining groups taken as alkyl group., , , , 11., , 12., , 13., , 14., , 15., , 16., , From which of the following compounds suffix “oate” is added ?, , (A) aldehyde (B) ketone (C) ester (D) ether, In IUPAC nomenclaure of cyanide compound which suffix is added ?, , (A) cyano (B) cyanide (C) cyanate (D) nitrile, Compounds with which hybridization of carbon get suffix ‘ene’ in IUPAC nomenclature ?, (A) dsp? (B) sp° (©) sp’ (D) sp, , Mention the IUPAC name of CH,CH,COOCH,,., , (A) butanoate (B) ethyl ethanoate (C) Methyl propanoate (D) Methyl propanoate, Identify the formula of butane nitrile :, , (A) CH,CH,CH,CN (B) CH,CH,CH,NH,, , (C) CH,CH,CH,CH,CN (D) CH,CH,CH,CH,NO,, , In which compound having only one functional group, prefix is added in nomenclature ?, , (A) alcohol (B) ether (C) amide (D) ketone, , , , , , Answers : 11. (C), 12. (D), 13. (B), 14. (D), 15. (A), 16. (B), , , , , , 477

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ysyapa¥) The Leaming App For, , NEET JEE JET RAS, , e Homologous series and isomerism, , Series of compounds having difference of — CH, — between two successive member is, called homologous series. eg. alkane series., , CH,, C,H, CyHy CH CAL,, Compounds having same molecular formula but different properties are called isomers of, , each other and this phenomenon is called isomerism., , , , e Classification of isomerism as follows :, Isomerism, L, L L, Structural isomerism Stereo isomerism, , (D, Q), (3), (4), (5), (6), , | 1., , , , , , chain isomerism conformational geometrical optical, position isomerism isomerism isomerism isomerism, functional isomerism L 4 L, metamerism staggered as enantiomers, Tautomerism eclipsed trans diasteveomers, ring-chain isomerism meso, , Chain isomerism : arrangement of carbon atom is linear or branched., eg., CH, — CH, — CH,-— CH, and CH, — CH— CH,, n— butane |, CH,, , iso butane, , Position isomerism : Position of functional group is different., eg. CH,— CH,- CH,- OH and CH, - CH- CH,, Propan-I-ol - | :, OH, propan — 2— ol, Functional group isomerism : Functional groups are different., eg., CH, — CH, - COOH and CH, = COOCH,, Propanoic acid Methyl ethanoate, , This isomerism is observed in ester-acid alcohol-ether, aldehyde-ketone and 1°, 2°, 3° amine., , metamerism : functional group is same but alkyl groups connected on both side have, different numbers of carbon atoms., eg., CH, — O— CH,CH,CH, and = CH,CH,— O— CH,CH,, , l-methoxy propane Ethoxy ethane, , This isomerism is observed in ether, ester, 2° and 3° amine., , 478

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The Learning App For, IAM NEET JEE JET RAS, , Tautomerism : Isomers form due to migration of o — hydrogen atom., , eg, CH,— C- CH, — CH,= C—CH,, ll |, oO OH, keto form enol form, , Ring chain isomerism : one isomer has cyclic structure and other isomer has linear chain structure., , eg., CH, and CH, — CH= CH,, , Propene, CH,— CH,, , Cyclo propane, , , , 17., , 18., , 19., , 20., , 21., , 22., , 23., , 24., , 25., , 26., , 27., , 28., , How do successive members of homologous series differ from each other ?, , (A) — CH, group (B) — CH, group (C) — C,H, group (D) — CH group, Between successive members of alkane homologous series, difference between molecular, mass IS ...... ®, , (A) 16 amu (B) 12 amu (C) 14 amu (D) 18 amu, Which of the following pair shows functional group isomerisms ?, , (A) aldehyde and alcohol (B) alcohol and amine, , (C) carboxylic acid and aldehyde (D) alcohol and ether, , How many isomers does pentane chain contain ?, , (A) 2 (B) 3 (Cc) 4 (D) 6, , How many isomers of C,H,N compound having amine group ?, , (A) 5 (B) 3 (Cc) 4 (D) 6, , How many chain isomers are possible for C,H, ?, , (A) 3 (B) 5 (Cc) 4 (D) 6, , Which of the following compound does not show position isomerism ?, , (A) butene (B) butanal (C) but-1-amine (D) butyne, , How many chain isomers are possible for pentanol ?, , (A) 4 (B) 5 (C) 6 (D)7, Which of the following is not isomer of diethyl ether ?, , (A) Methyl propyl ether (B) butan-1-ol, , (C) 2-Methyl-propan-1-ol (D) diethyl ketone, , Number of isomers of C,H,,O ...... :, , (A) 7 (B) 8 (C5 (D) 6, , Isomer of ethyl alcohol is, , , , (A) diethyl ether (B) dimethyl ether (C) ethanal (D) acetone, ait type of isomerism is observed in urea., , (A) chain (B) position (C) geometrical (D) tautomerism, , 479