SOLVED EXAMPLES Ex. 1 How may 1°, 2°, 3° and 4° carbon atoms are present in following molecule. CH3 CH3 CH C CH2 CH CH3 CH3 CH3 CH2 CH3 Sol. 1° Carbon atoms = 6, Note : Primary, secondary, tertiary & quaternary carbon atoms in a molecule are denoted by the letters p, s, t and q respectively. Ex. 2 How many 1°, 2°, 3° and 4° carbon atoms are present in following molecule. CH3 2° Carbon atoms = 2, 3° Carbon atoms = 2, 4° Carbon atom = 1 CH3 C CH2 CH CH3 CH3 CH3 1° CH3 Sol. 1° CH3 4° C 2° 3° 1° CH2 CH CH3 1° CH3 1° CH3 1° Carbon atoms = 5, Ex. 3 2° Carbon atom = 1, Write the IUPAC name of following compounds. (i) H 3C CH2 CH COOH 3° Carbon atom = 1, 4° Carbon atom = 1 (ii) 3-Bromocyclohexane-1-sulphonic acid OC 2H5 CH3 (iii) CH3 CH3 (iv) 3-Cyano-3-ethoxy-4-nitropentanoyl bromide SO3H Sol. (i) 2-Ethoxybutanoic acid (ii) Br CN (iii) 1,1,2-Trimethylcyclopentane (iv) CH3 CH C O CH2 C Br NO2 OC2H5 Ex. 4 Draw the structure of following IUPAC name. (i) (ii) 3-Methoxycarbonylpropanoic acid O Sol. (i) 3-Ethypenta-1,4-diyne (ii) HO OCH3 O NOMENCLATURE OF ORGANIC COMPOUND Ex. 5 Sol. Make the structure of following organic compounds – 1. Isopropylidene Bromide 2. Active amylene Iodide 4. Isobutylene 5. Trimethylene glycol Br 1. CH3 C Br CH3 I OH 2. CH3 C CH2 I 3. CH3 C CH2 OH CH2 CH3 3. Isobutylene glycol 4. H 3C C = CH 2 CH3 CH 3 Ex. 6 The correct IUPAC name of the following compound is O=CH CH2 CH CHO H C=O (A) 1,1-diformyl propanal (B) 3-formyl butanedial (C) 2-formyl butanedial (D) 1, 1,3-ethane tricarbaldehyde Sol. (C) The principal functional group is – CHO. 4 3 2 5. CH2 CH2 CH2 OH OH 1 O=CH CH2 CH CHO CHO 2-formyl butanedial Ex. 7 Sol. The correct IUPAC name of compound CH3 CH2 C CH CHO is O CN (A) 2-cyano-3-oxopentanal (B) 2-formyl-3-oxopentanenitrile (C) 2-cyano-1, 3-pentanedion (D) 1, 3-dioxo-2-cyanopentane (B) Here the main functional group is – CN, which had nitrile suffix and CHO and CO are taken substituents. 5 4 3 2 CH3 CH2 C CH CHO (2-formyl-3-oxopentanenitrile) 1 O CN Ex. 8 IUPAC name of CH3 C CH C OCH3 O C=O O CH3 (A) Methyl-2, 2-acetyl ethanoate (C) Methyl-2-acetyl-3-oxobutanoate Sol. (B) 2, 2- acetyl-1-methoxy ethanone (D) none of these (C) The principal functional groups is ester group. CH3 C CH C OCH3 (Methyl-2-acetyl-3-oxobutanonate) O C=O O CH3 Ex. 9 The IUPAC name of compound HO C=O CH3 is CH3 C=C C H Sol. NH2 Cl (A) 2-amino-3-chloro-2-methyl-2-pentenoic acid (B) 3-amino-4-chloro-2-methyl-2-pentenoic acid (C) 4-amino-3-chloro-2-methyl-2-pentenoic acid (D) none of these (B) The principal functional group is carboxylic acid (–COOH) 1 5 HO C=O CH3 2 3 4 CH3 C=C C H NH2 Cl 3-amino-4-chloro-2-methyl-2-pentenoic acid Ex. 10 How many carbons are in simplest alkyne having two side chains? (A) 5 (B) 6 (C) 7 Sol. (B) Ex. 11 The compound name trichloroethane is (A) Westron (B) Perclene Cl C=C (C) Westrosol (C) Trichloroethene is westrosol Ex. 12 The type of unsaturation present in crotonic acid is (A)  (B)  (C)  (A) The type of unsaturation present in crotonic acid is . Sol. (D) Orlone Cl Sol. H (D) 8 Cl 1, 1, 2-trichlorethene(westrosol) (D)  O CH3 CH=CH C 4 3 2 1 OH Crotonic acid or (2-Butenoic acid) O Ex. 13 IUPAC name of compound CH 3CH 2OCCH2CH 2CH3 is (A) Propyl propanoate (C) Propyl butanoate Sol. 1 (B) Ethyl butanoate (D) Ethyl propanoate 3 2 4 (B) CH3 CH2 O C CH2 CH2 CH3 Ethyl butanoate O Ex. 14 The IUPAC name of the compound given below is Sol. (A) Bicyclo [3,2,1] octane (C) Spiro [2, 2] octane (A) Ex. 15 The structure of spiro [3, 3] heptane is (A) (B) Bicyclo [3,2,2] octane (D) None of these (B) Sol. (B) Ex. 16 The structure of bicyclo [1.1.0] butane is (A) Sol. (D) (B) (C) (D) (C) (D)