HYDROCARBON (13th).pdf

1. ORGANIC CHEMISTRY HYDROCARBON C O N T E N T S EXERCISE - I EXERCISE - II EXERCISE-III(A) EXERCISE III(B) ANSWER KEY

2. (1) R–CCH C 300 200 Ni , H2       or R–CH=CH2 Sabatier senderens reaction (2) R–X 4 LiAlH , Hi P d Re HCl Cu Zn          (3) R–Mg–X 2 3 RNH or NH or ROH or HOH        (4) RX reaction Wurtz ether dry , Na       (5) RX reaction s ' Frankland Zn        (6) O || ROH or Cl C R        Hi / P d Re or O || R C R   or RCHO (7) O || R C R   reduction s ' Clemension HCl . Conc / Hg Zn          (8) R | O C R   reduction Kishner / Wolf NH N H 2 2             or (RCH2 CH2 )3 B       O H2 (9) RCOONa         CaO NaOH (10) RCOONa           synthesis ic electrolyt s ' Kolbe (1) RX C 400 or light UV or h , X2                 (2)       Nitration R-N (3) acid Sulphonic Alkyl 7 2 2 O S H on Sulphonati             (4) SO2 + Cl2          h reaction ed Re RSO2 Cl (5) ion Isomerisat HCl / AlCl3        branched alkanes (6) C 700 500 Pyrolysis         Alkenes + CH4 or C2 H6 (7) C 500 O Al oxide V or Mo or Cr 3 2              Aromaticcompound (8) reaction up step N CH 2 2       Higher alkane (9)      2 O CO2 + H2 O Combustion R–H or R–R or Cn H2n+2 GMP GR REACTION CHART FOR ALKANES

3. (1) R–CH2 –CH2 –OH O H SO H . conc 2 4 2        (2) R–CH2 –CH2 –X HX KOH . alc       (3) R–CH2 –CH 2 X alkene higher for dust Zn       (4) X X | | CH CH R 2        dust Zn (5) R–C  CH C 300 200 H , Ni 2        (6) COOK RCH | COOK RCH                 synthesis ic electrolyt s ' Kolbe (7) (C2 H5 )4 N+ OH    (8) O || R CH CH O C R 2 2            Pyrolysis (9) R–H       Pyrolysis (10) CH2 =CHCl     2 CuR (1) C 300 200 Ni H , 2       R–CH2 –CH3 (2)   2 X R–CHX–CH2 X (3)    HX R–CHX–CH3 (4)       Peroxide , HBr R–CH2 –CH2 Br (5)     HOCl R–CH(OH)–CH2 Cl (6) O H SO H . dil 2 4 2       R–CH2 (OH)–CH3 (7) C 300 Ag O 2 / 1 2      (8)       2 2N CH (9)     3 BH (RCH2 CH2 )3 B (10) 4 2 ) CO ( HCo H CO       CHO | CH CH R 3   + CHO | CH CH R 2 2   (11)    2 O CO2 + H2 O (12)     4 S O O OH OH | | CH CH R 2   (13) 4 nO alkalineKM % 1 reagent Bayer       OH OH | | CH CH R 2   (14)       oxidant strong O || OH C R   + CO2 + H2 O (15) reaction s ' chalev iles Pr acid Per       (16) Ozonolysis O H O 2 3       + (17) P high C 200 O2    Polyalkene (18) C 500 Cl2     Substitutionproduct (19) C 300 200 ) SO ( Al 3 4 2         Isomerisation (20)        anhydride acetic R–CH2 =CH–COCH3 Methylalkenylketone (21)     Alkane Higher alkane R–CH=CH2 or Cn H2n REACTION CHART FORALKENES GMP GR

4. (1) CH2 Br–CH2 Br         2 NaNH or KOH . alc (2) CH3 –CHBr2        2 NaNH , KOH . alc (3) CHCl3        powder Ag (4) CHBr2 –CHBr2       dust Zn (5) CHBr || CHBr   Zn (6) CH2 =CH–Cl        2 NaNH , KOH . alc (7) COONa HC || COONa HC             synthesis ic electrolyt s ' Kolbe (8) CaC2     O H2 (9) 2C + H2 process s ' Berthelot C 1200 , arc electric          (10) CH3 –CCH        X R ) ii ( Na ) i ( (10) CH3 –CCH         X R ) ii ( MgI CH ) i ( 3 (1) Ni H2   C2 H4 , C2 H6 (2)   2 X C2 H2 X4 (3) Peroxide HBr     CH3 BrCH2 Br (4) Peroxide No HBr     CH3 –CHBr2 (5)     HOCl Cl2 CHCHO (6)        2 ) CN ( Ba , HCN CH2 =CHCN (7)        2 3 Hg , COOH CH CH3 CH(OCOCH3 )2 (8) ) reaction s ' Kucherov ( SO H . dil , C 80 , Hg 4 2 2            CH3 CHO (9)       4 2SO H . Conc CH3 CH(HSO4 )2 (10) reaction Bunsen & det Ca AsCl3     CHCl=CHAsCl2 (11) 4 2 5 2 HgSO O H / OH H C        CH3 CHO (12) 4 ) CO ( Ni HOH CO        CH2 =CH–COOH (13) C 160 , Ni EtOH CO         CH2 =CH–COOEt (14)      2 NaNH Na–CC–Na (15) ) agent Re s ' Tollen ( OH NH AgNO 4 3          Ag–CC–Ag (16)          OH NH Cl Cu 4 2 2 Cu–CC–Cu (17)        2 O Combustion CO2 + H2 O (18)        agent Re Bayer CHO HCOOH | CHO  (19) Ozonolysis O3        O H2 HCOOH (20) ) tube iron hot d (Re ion Trimerisat       benzene (21) ] ) CN ( Ni [ ion Trimerisat 2       C8 H8 or 1,3,5,7-cyclo octa tetraene (22)        ] ) NH ( Cu [ on Dimerisati 2 3 butenyne (23)   s (24) ) HgO BF ( OH CH 3 3       methylal C2 H2 REACTION CHART FORALKYNES GMP GR

5. Exercise 1 Q.1 Number of required O2 mole for complete combustionofone mole ofpropane – (A) 7 (B) 5 (C) 16 (D) 10 Q.2 How muchvolume ofair willbe needed for complete combustionof10 lit. ofethane – (A) 135 lit. (B) 35 lit. (C) 175 lit. (D) 205 lit. Q.3 When n-butane is heated in the presence ofAlCl3/HClit willbe converted into – (A)Ethane (B) Propane (C) Butene (D) Isobutane Q.4 The reacting species of alc. KOH is – (A) OH– (B) OR+ (C) OK+ (D) RO– Q.5 The product of reaction between one mole of acetylene and two mole of HCHO in the presence of Cu2Cl2 – (A) HOCH2 – CC – CH2OH (B) H2C = CH – CC – CH2OH (C) HC  C – CH2OH (D) None ofthese Q.6 During the preparation ofethane byKolbe’s electrolytic method using inert electrodes the pH ofthe electrolyte – (A) Increases progressivelyas the reaction proceeds (B) Decreases progressivelyas the reaction proceeds (C) Remainsconstant throughout the reaction (D) Maydecrease ofthe the concentrationofthe electrolyte is not veryhigh Q.7 Ethylene formsethylene chlorohydrinbytheactionof– (A) DryHCl gas (B) Drychlorine gas (C) Solutionofchlorine gas inwater (D) Dilutehydrochloric acid Q.8 Anti–Markownikoff’s additionofHBr is not observed in – (A) Propene (B) But–2–ene (C) Butene (D) Pent–2–ene Q.9 Which alkene onheating withalkaline KMnO4 solutiongivesacetone and a gas, whichturns lime water milky– (A) 2–Methyl–2–butene (B) Isobutylene (C) 1–Butene (D) 2–Butene Q.10 B      Lindlar R–CC–R      3 NH / Na A A and B are geometrical isomers (R–CH=CH–R) – (A)Ais trans, B is cis (B)Aand B both are cis (C)Aand B both are trans (D)Ais cis, B is trans Q.11 Which is expected to react most readilywith bromine – (A) CH3CH2CH3 (B) CH2=CH2 (C) CHCH (D) CH3–CH=CH2 Q.12 Bythe additionof CO and H2O onethene, the following is obtained – (A) Propanoic acid (B) Propanal (C) 2–Propenoic acid (D) None ofthe above

6. Q.13 An alkyne C7H12 onreactionwith alk. KMnO4 and subsequent acidification with HClyields a mixture of 3 3 CH | CHCOOH CH  + CH3CH2COOH. The alkyne is – (A) 3–Hexyne (B) 2–Methyl–3–hexyne (C) 2–Methyl–2–hexyne (D) 2–Methyl–2–hexene Q.14 Acompound (C5H8) reactswithammonicalAgNO3 to givea white precipitate and reactswithexcess of KMnO4 solutionto give (CH3)2CH–COOH. The compound is – (A) CH2=CH–CH=CH–CH3 (B) (CH3)2CH–CCH (C) CH3(CH2)2CCH (D) (CH3)2C=C=CH2 Q.15 Whichofthe following reagents cannot be used to locate the position oftriple bond in CH3–CC–CH3 (A) Br2 (B) O3 (C)  2 2 Cu (D) KMnO4 Q.16 CH3–CH2–CCH CH3CC–CH3 A and B are – (A) alcoholic KOH and NaNH2 (B) NaNH2 and alcoholic KOH (C) NaNH2 and Lindlar (D) Lindlar and NaNH2 Q.17 B       OH / O H THF / BH 2 2 3      O H3 A A and B are – (A) Both (B) Both (C) (D) Q.18 B       OH O H THF BH , 2 2 3 CH3–CCH        4 2 4 SO H / HgSO A A and B are – (A) 3 3 2 3 CH C CH , CHO CH CH || O   (B) CHO CH CH CH C CH || O 2 3 3 3   (C) CH3CH2CHO (both) (D) O || CH C CH 3 3   (both) Q.19 CH3CH=CH2       OH / O H NaBD 2 2 4 product X X is – (A) OH | D CH CH CH 2 3   (B) D | OH CH CH CH 2 3  

7. (C) OD | CH CH CH 3 3   (D) noneis correct Q.20 CH2=CH–CH=CH2      Br CCl3 product. The major product is – (A) Br–CH2–CH=CH–CH2–CCl3 (B) Br | CCl CH CH CH CH 3 2 2     (C) 3 2 2 CCl | Br CH CH CH CH     (D) None is correct Q.21 Mixture of onemoleeach of etheneand propyne on reaction with Nawill form H2 gas at S.T.P. – (A) 22.4 L (B) 11.2 L (C) 33.6 L (D) 44.8 L Q.22 Dehydrationof2, 2, 3, 4,4–pentamethyl–3–pentanolgave two alkenesAandB.Theozonolysisproducts ofAand B are - (A) Agives 3 3 3 3 ) CH ( C C C ) CH ( || O   and HCHO B gives 3 3 2 3 ) CH ( C CH C CH || O    and HCHO (B) Agives 3 3 3 3 ) CH ( C C C ) CH ( || O   and HCHO B gives 3 3 3 3 3 CH | ) CH ( C C C CH | || CH O    and HCHO (C) A gives 2 3 3 3 ) CH ( CH C C ) CH ( || O   and HCHO B gives 3 3 2 3 ) CH ( C C CH ) CH ( || O    and CH3CH2CHO (D) None of these Q.23 CHCH 2 2 4 Cl Cu Cl NH      product Product is – (A) Cu–CC–Cu (B) CH2=CH–CCH (C) CHC–Cu (D) Cu–CC–NH4

8. Q.24 3 3 3 3 3 CH | CH C CH C CH | | CH CH            4 4 KMnO / NaIO products, Products are – (A) 3 3 CH C CH || O   , (CH3)3C–COOH (B) 3 3 CH C CH || O   , (CH3)3C–CHO (C) OH C CH || O 3   , (CH3)3C–COOH (D) None is correct Q.25 Alkene A      O H / O 2 3 3 3 CH C CH || O   + CH3COOH + O || COOH C CH3   A can be – (A) (B) 3 3 2 3 CH HC CH C CH || ) CH ( C     (C) Both correct (D) None is correct Q.26      2 R reagent      1 R reagent R1 and R2 are – (A) Cold alkaline KMnO4, OsO4/H2O2 (B) Cold alkaline KMnO4, HCO3H (C) Cold alkaline KMnO4, CH3–O–O–CH3 (D) C6H5CO3H, HCO3H Q.27 3 3 CH | C H || C H | CH          4 KMnO alkaline A, whichistrue about this reaction? (A)Ais meso 1, 2–butan–di–olformed bysyn addition (B)Ais meso 1, 2–butan–di–ol formed byanti addition (C)Ais a racemic mixture ofd and l, 1, 2–butan–di–olformed byantiaddition (D)Ais a racemic mixture ofd and l 1,2–butan–di–olformed bysyn addition

9. Q.28 + CH3MgBr      O H3 A       4 2SO H . Con B       Zn / O H / O 2 3 C A, B and C are – A B C (A) (B) (C) (D) Q.29   A A can be – (A) Conc. H2SO4 (B) alcoholic KOH (C) Et3N (D) t-BuOK Q.30 BrCH2–CH2–CH2Br reacts withNa in the presence of ether at 100 °C to produce – (A) BrCH2–CH=CH2 (B) CH2=C=CH2 (C) (D)Allofthese Q.31 Which has least heat ofhydrogenation – (A) (B) (C) (D) Q.32 O H / NaOH / NaBH ) 2 ( THF / O H / ) OAc ( Hg ) 1 ( 2 4 2 2           A. Ais – (A) (B) (C) (D) Q.33 CH3–CH=CH–CH3   x product isY (non–resolvable) then X can be – cis (A) Br2 water (B) HCO3H (C) Cold alkaline KMnO4 (D) allofthe above

10. Q.34 Electrophilic additionreactionis not shownby (A) 3 3 2 CH | CH C CH   and Br2 (B) CHCH2 and HO–Cl (C) CH3–CCH and CH3MgBr (D) CH2=CH2and dil. H2SO4 solution Q.35 Amixture of CH4, C2H4 and C2H4 gaseous are passed through a Wolfbottle containing ammonical cuprous chloride. Thegas coming out is (A) Methane (B)Acetylene (C) Mixture ofmethane and ethylene (D)originalmixture Q.36 Whichreagent is the most usefulfor distinguishing compound Ifromthe rest ofthe compounds CH3CH2CCH CH3CCCH3 CH3CH2CH2CH3 CH3CH=CH2 I II III IV (A) alk. KMnO4 (B) Br2/CCl4 (C) Br2/CH3COOH (D)AmmonicalAgNO3 Q.37 CH2=CH–CH=CH2 + CHCOOH | | CHCOOH   product X by reaction R. X and R are (A) DielsAlder (B) Friedel-Crafts (C) DielsAlder (D) Friedel-Crafts

11. Exercise 2 1. An organic compound (A) (C5 H8 ) on hydrogenation gives compound B(C5 H12 ). CompoundAon ozonolysis gives Formaldehyde & 2 keto propanal. Deduce the structure of compound A. 2. An organic compoundAof vapour density 49.5 gave a dihydric alcohol(B) on treatment with moist silver oxide but an alkene (C) on heating with zinc dust. IdentifyA, B & C. Give IUPAC name of the compound obtained by ozonolysis. 3. An alkanol (A) forms an alkene (B) on heating with concentrated H2 SO4 (B) is allowed to react with Br2 water & the product is dehydrogenated with alcoholic KOH giving a compound (C). C forms D when hydrolysed with dilute H2 SO4 in presence of dilute HgSO4 . D, not a ketone can also be produced by dehydrogenation ofA. IdentifyA, B, C & D & explain the reaction. 4. An organic compound (A) C5 H9 Br which readily decolourises Br2 water & KMnO4 solution gives (B), C5 H11 Br on treatment with Sn/HCl. The reaction ofAwith NaNH2 produce C with evolution of NH3 . C neither reacts with Na nor forms a any metal acetylide but reacts with Lindlar catalyst to give D & on reaction with Na/liq. NH3 produce E. Both the compounds D & E are isomeric. Give structures ofAto E with proper reasoning. 5. When 1, 4 hexadiene 3ol is dissolved in H2 SO4 it is completely converted into 3, 5 hexadiene 2-ol. How do you account for this. 6. Acompound ofthe molecular formula C5 H12 has three isomers X, Y& Z. Monochloro derivative of X yield the compoundA, B on dehydrohalogenation with alcoholic KOH.Ayields acetaldehyde & propionaldehyde on ozonolysis but B yields formaldehyde & n – butyraldehyde. Identify X, Y & Z & also A& B & give the reaction. 7. The hydrocarbon A, adds one mole of H2 in presence of Pt catalyst to form n-hexane. WhenAis oxidised rigorously with KMnO4 a single carboxylic acid, containing 3 carbon atoms is isolated. Give the structure ofA& explain. 8. What will be the product in the following reaction (i) +  (ii) +  (iii) + Br2  A 1 3 2 2 3 3 . ( .) . NaMH equiv NH CH I    B 9. Conversion: (i). C2 H2  racemic 2, 3 dibromobutane (ii) 2 butyne  2 pentyne (iii) Ethyne Acetone (iv) Methane  n Butane (v) Ethene  Propionic Acid 10. Hydrocarbon (A) C6 H10 ontreatment with H2 /Ni; H2 /Lindlar catalyst & Na/NH3 forms three different reduction products B, C & D respectively. Adoes not form any salt with ammoniacal solution but forms a salt (E) on heating with NaNH2 in an inert solvent. Compound (E) reacts with CH3 I to give F. Compound D on oxidative ozonolysis gives n butanoic acid along with other products. Give structure ofAto F with proper reasoning.

12. 11. There are 6 different alkenes A, B, C, D, E, F. Each on addition of 1 mole of hydrogen gives G which is the lowest molecular weight hydrocarbon containing only one assymmetric carbon atom. None of the above alkene give acetone as a product on ozonolysis. Give the structures ofAto F. 12. An organic compound (A) contains 85.1% bromine & reacts with moist Ag2 O to yield compound B (C2 H6 O2 ). B is oxidised to an acid (C) which evolves CO & CO2 on warming with concentrated H2 SO4 . SubstanceAon boiling with alcoholic KOH yields a gas D which on being passed through ammoniacal Cu2 Cl2 solution deposits a red solid containing 84.1 % Cu. DeduceAto D. 13. IdentifyAto E PhCHCl CH2 Cl Alcoholic KOH     A 1 2 2 . . NaNH Cyclopentyl iodide     B 14. What will be products in the following reaction? (a) PhC CH NaNH MeI 2    A Na NH e / ( ) 3    B (b) PhCH = CH2 Br2    A 1 3 2 2 3 . ( ) . NaNH equi CH I    B (c) PhC  C – H 1 2 4 3 2 . . HgSO H O NH OH      A 15. One of the constituent of turpentine is -pinene having molecular formula C10 H16 . The following scheme give reaction of -pinene. Determine the structure of–pinene & of the reaction products A through E. E(C10 H18 O2 ) A(C10 H16 Br2 )  H2 O  Br2 /CCl4 C10 H16 O(D) PhCO H 3    –pinene Br H O 2 2      B (C10 H17 OBr) 16. What are Ato D & a  f for the following reaction: (i) (ii) 17. What areAto K for the following reactions (i) PhC  CH + CH3 MgX  A ArCH Cl 2     B Li NH / 3    C. (ii) PhCH2 CH2 CH3 + Br2 h    D alcoholic KOH    E  Cold dilute KMnO4 G hot KMnO4     F

13. (iii) H    (iv) I    (v) CF3 – CH = CH2 HBr    J (vi) NBS h ,      K 18. A hydrocarbon (A) ofmolecular weight 54 reacts with an excess of Br2 in CCl4 to give a compound (B) whose molecular weight is 593% more than that ofA. However on catalytic hydrogenation with excess of H2 (A) forms C whose molecular weight is 7.4% more than that of A. A reacts with CH3 CH2 Br in presence of NaNH2 to give another hydrocarbon (D) which on ozonolysis yields diketone E. E on oxidation gives propionic acid. Give structuresAto E with proper reasons. 19. A 10g mixture of isobutane & isobutene requires 20g of Br2 in CCl4 for complete addition. If10 g of the mixture is catalytically hydrogenated & the entire alkane is monobrominated in presence of light at 1270 C, which exclusive product & how much of it would be formed. (At wt. of Bromine = 80) 20. A& B on combustion analysis indicated C = 88.82%, H = 11.18%. Both decolourises Br2 solution. A gives a precipitate with ammoniacal AgNO3 solution. A oxidises to CO2 & propionic acid. Compound B does not give a ppt. with ammoniacalAgNO3 & oxidises to CO2 & oxalic acid. Give structures ofA& B. 21. An organic compound A (C6 H10 ) on reduction first gives B(C6 H12 ) & finally C(C6 H14 ). A on ozonolysis gives two aldehydes D(C2 H4 O) & E(C2 H2 O2 ). Oxidation of B with acidified KMnO4 gives the acid F(C4 H8 O2 ). Determine the structures ofthe compoundsAto F with proper reasoning. 22. Dehydrobromination of compoundsA B yield the same alkene C. Alkene C can regenerateA& B by addition of HBr in presence or absence of peroxide respectively. Hydrolysis of A & B gives isomeric products D & E respectively. 1, 1 diphenyl ethane is obtained on reaction of C with benzene in presence of H+ . Give the structures ofAto E with proper reasons. 23. Identify n, A& B CH2 = CH – CH = CH – CH = CH – (CH2 )5 C  C – (CH2 )6 – C  C – CH3  n moles of H2 /Ni A ( ) 2 5 2 n moles of H Ni     B red P HI      CH3 (CH2 )9 –CH2 Br 24. The following cyclisation has been observed in the oxymercuration & demercuration of this unsaturated alcohol. Propose a mechanism for this reaction. 1 2 2 4 . ( ) . Hg OAC NaBH    

14. 25. Propose structures for intermediates & productsAto K 26. An alkene (A) yields acetone & an aldehyde on ozonolysis. The aldehyde is easily oxidised to an acid (B) which ontreatment with Br2 in presence of P yields a compounds C. C on hydrolysis gives a hydroxy acid D. D can also be obtained from acetone by the reaction of HCN followed by hydrolysis. IdentifyA, B, C & D & give the reactions. 27. Identify the following (A to D). 28. An alkyne (A) of molecular formula C8 H12 produces B & C on reaction with Na/Liq. NH3 & H2 /Pd (Lindlar’s Catalyst)). D(isomer of B) gives acetone as one of the products on ozonolysis & on electrophilic addition with H+ gives E. E on ozonolysis gives 2, 7 octanedione. IdentifyAto E. 29. Conversion Me2 C = CH – CH CH CMe Citral 2 2 = CHCHO + H3 O+ 

15. Explain with mechanism. 30. Write the structuralformula of limonene fromthe following observation: (a) Limonene when treated with excess H2 & Pt catalyst, the product formed is 1 isopropyl· 4 methyl cyclohexane (b) When it is treated with O3 & then Zn/H2 O the products of the reaction are HCHO & following compound

16. Exercise 3(A) Q.1 Alcoholic solution ofKOH is a specific reagent for – (A)Dehydration (B) Dehydrogenation (C) Dehydro halogenation (D) Dehalogenation Q.2 Ofthe following, unsaturated hydrocarbons are – (A) ethyne (B) cyclohexane (C) n–propane (D) ethene Q.3 1-chlorobutane onreaction withalcoholic potashgives – (A) 1–butene (B) 1–butanol (C) 2–butene (D) 2–butanol Q.4 The hybridisation ofcarbon atoms in C–C single bond of HCC–CH=CH2 is – (A) sp3–sp3 (B) sp2–sp3 (C) sp–sp2 (D) sp2–sp2 Q.5 The product(s) obtained via oxymercuation (HgSO4 + H2SO4) of1–butyne would be – (A) O || CH C CH CH 3 2 3    (B) CH3–CH2–CH2–CHO (C) CH3–CH2–CHO + HCHO (D) CH3–CH2–COOH + HCOOH Q.6 When cyclohexane is poured on water, it floats, because – (A) Cyclohexand is in ‘boat’ form (B) Cyclohexane is in ‘chair’form (C) Cyclohexane is in ‘crown’ form (D) Cyclohexane is less dense than water Q.7 Whichofthe following compoundswillshow geometricalisomerism? (A) 2–butene (B) Propene (C) 1–phenylpropene (D) 2–methyl–2–butene Q.8 In the compound CH2=CH–CH2–CH2–CCH, the C2–C3 bond is ofthe type – (A) sp–sp2 (B) sp3–sp3 (C) sp–sp3 (D) sp2–sp3 Q.9 Whichone ofthe following alkenes willreact fastest with H2 under catalytichydrogenation condition– (A) (B) (C) (D) Q.10 Propyne and propene can be distinguished by– (A) conc. H2SO4 (B) Br2 in CCl4 (C) dil. KMnO4 (D)AgNO3 inammonia Q.11 In the presence of peroxide, hydrogen chloride and hydrogen iodide do not give anti–Markovnikov addition to alkene because – (A) bothare highlyionic (B) one is oxidising and theother is reducing (C) one ofthe step is endothermic inboth the cases (D)Allthe steps are exothermic in both cases

17. Q.12 Hydrogenation oftheabove compound in the presence ofpoisoned paladiumcatalyst gives – (A)Anopticallyactive compound (B)Anopticallyinactive compound (C)Aracemic mixture (D)Adiastereomeric mixture Q.13 The reactionofpropene with HoClproceeds via the additionof– (A) H+ infirst step (B) Cl+ infirst step (C) OH– infirst step (D) Cl+ and OH– insingle step Q.14 The nodal plane in the –bond ofethene is located in – (A) themolecular plane (B) a plane parallelto the molecular plane (C)aplaneperpendicular to themolecular planewhichcontainsthecarbon–carbon–bondatright angle (D) aplane perpendicular to themolecular plane which contains the carbon–carbon–bond Q.15 Consider the following reactions – 3 3 3 CH D | | CH CH CH C H    + ‘X’ + HBr Identifythestructure ofthe major product ‘X’ (A) 3 2 • 3 CH D | | H C CH CH C H    (B) 3 3 • 3 CH D | | CH C CH C H    (C) 3 3 • 3 CH D | | CH CH C C H    (D) 2 3 • 3 CH | CH CH H C C H    Q.16 Identifya reagent fromthe following list which caneasilydistinguish between1–butyne and 2-butyne- (A) bromine, CCl4 (B) H2, Lindlar catalyst (C) dilute H2SO4, HgSO4 (D) ammoniacalCu2Cl2 solution Q.17 C6H5–CC–CH3 4 2 4 SO H HgSO      A (A) (B) (C) OH | CHCH C H C 3 5 6   (D) OH | CH C CH H C 3 5 6   

18. Q.18 O H H 2     x ) mixture (    2 Br 5 compounds ofmolecular formula C4H8Br2 Number ofcompoundsinX willbe: (A) 2 (B) 3 (C) 4 (D) 5 Q.19 2–hexyne can be converted into trans–2–hexene bythe action of: (A) H2–Pd-BaSO4 (B) Liin liq. NH3 (C) H2–PtO2 (D) NaBH4 Q.20 When PhenylMagnesiumBromide reacts with tert. butanol, whichofthefollowing is formed? (A)Tert. butylmethylether (B)Benzene (C)Tert. butylbenzene (D) Phenol Q.21 1–bromo–3–chlorocyclobutanewhentreatedwithtwo equivalents ofNa, inthe presenceofetherwhich ofthe followingwillbe formed? (A) (B) (C) (D) Q.22 Cyclohexene is best prepared fromcyclohexanolbywhichofthe following: (A) conc. H3PO4 (B) conc. HCl/ZnCl2 (C) conc. HCl (D) conc. HBr Exercise 3(B) Q.1 3 2 2 3 CH CH C ) CH ( | Cl       KOH . alc ? Q.2 Br | CHCH CH H C 3 2 5 6 heat KOH . alc      ?     HBr ? Q.3 C(C6H12), anopticallyactive hydrocarbon whichoncatalytic hydrogenationgivesan opticallyinactive compound, C6H14. Q.4 Draw the stereochemicalstructure ofthe product inthe following reactions. R–CC–R catalyst Lindlar H2   Q.5 Write downthestructures ofthe stereoisomers formed whencis–2–butene isreacted with bromine. Q.6 AnorganiccompoundE(C5H8)onhydrogenationgivescompoundF(C5H12). CompoundE onozonolysis gives formaldehyde and 2–ketopropanal. Deduce the structureofcompound E. Q.7 Give the structuresofthe major organicproducts from3–ethyl–2–pentene under eachofthe following reactionconditions. (a) HBr in the presence ofperoxide (b) Br2/H2O (c) Hg(OAc)2/H2O; NaBH4

19. Q.8 Analkylhalide,(X)offormulaC6H13Clontreatment withpotassiumtertiarybutoxidegivestwo isomeric alkenes (Y) and (Z) (C6H12). Both alkenes on hydrogenation give 2, 3–dimethylbutane. Predict the structures of(X), (Y) and (Z) Q.9 3,3–Dimethyl–butan–2–ol losesamoleculeof water in thepresenceof concentrated sulphuric acid to givetetramethylethyleneasamajor product. Suggest asuitablemechanism. Q.10 Onemoleof thecompoundA (molecular formulaC8H12), incapableofshowingstereoisomerism, reacts with only one mole of H2 on hydrogenation over Pd. Aundergoes ozonolysis to give a symmetrical diketone B (C8H12O2). What are the structure ofAand B? Q.11 Compound (A) C6H12 gives a positive test with bromine in carbon tetrachloride. Reactionof(A) with alkaline KMnO4 yields only(B) which is the potassium salt ofan acid. Write structure formulae and IUPAC name of(A) and (B). Q.12 The centralcarbon–carbon bond in 1,3–butadiene is shorter than that ofn–butane. Why? Q.13 Write the intermediate steps for eachofthe following reaction C6H5CH(OH)CCH C6H5CHCHCHO Q.14 Write the intermediatesteps for each ofthe following reaction.    H Q.15 Discuss the hybridisation ofcarbon atoms in allene (C3H4) andshow the –orbitaloverlaps. Q.16 Complete thefollowing –   1   2   3 Q.17 Complete thefollowing –   4   5   6 Q.18 Explainbrieflythe formationontheproducts giving the structuresofthe intermediates. (i)     HCl + + etc. But (ii)     HCl

20. Explainthenonformation ofcyclicproduct in(ii) Q.19 Carryout thefollowing transformationinnot more thanthree steps. CH3–CH2–CC–H  3 2 2 3 CH C CH CH CH || O     Q.20 CH2=CH– is more basic than HCC– Q.21 What would be the major product in each ofthe following reactions? (i) 3 2 3 3 CH | Br CH C CH | CH         OH H C 5 2 (ii) Catalyst s ' Lindlar H2   Q.22 On reactionwith4N alcoholic KOH at 175 °C 1–pentyneis slowlyconverted into equilibriummixture of 1.3% 1–pentyne (A), 95.2% 2–pentyne (B) and 3.5% 1,2–pentadiene (C). Give the suitable mechansismofformationofA, B and Cwith allintermediates. Q.23 Identify X, Yand Z in the following synthetic scheme and write their structures. Is the compound Z opticallyactive?Justifyyour answer. CH3CH2CC–H Br CH CH ) ii ( NaNH ) i ( 2 3 2      X         4 2 BaSO Pd / H Y        4 KMnO alkaline Z Q.24 Abiologicallyactivecompound, Bombykol(C16H30O) isobtained froma naturalsource. The structure ofthecompound is determined bythe following reactions. (a) On hydrogenation, Bombykol gives a compoundA, C16H34O, which reacts with acetic anhydride to give an ester. (b) Bombykol also reacts with acetic anhydride to give another ester, which on oxidative ozonolysis (O3/H2O2) gives a mixture of butanoic acid, oxalic acid and 10-acetoxydecanoic acid. DeterminethenumberofdoublebondsinBombykol.WritethestructuresofcompoundAandBombykol. How manygeometricalisomers are possible for Bombykol? Q.25 If after complete ozonolysis of one mole of monomer of natural polymer gives two moles of CH2O andonemoleof O CH C O | CH3    . Identifythemonomeranddrawtheall-cisstructureofnaturalpolymer. . Q.26       , H X COOH Cl / Zn ) ii ( O ) i ( 3 3       Y. Y. IdentifyXandY.

21. ANSWER KEY Exercise 1 Q.1 B Q.2 C Q.3 D Q.4 A Q.5 A Q.6 A Q.7 C Q.8 B Q.9 B Q.10 A Q.11 D Q.12 A Q.13 B Q.14 B Q.15 A Q.16 A Q.17 D Q.18 B Q.19 B Q.20 A Q.21 B Q.22 B Q.23 B Q.24 A Q.25 C Q.26 B Q.27 A Q.28 A Q.29 A Q.30 C Q.31 C Q.32 C Q.33 C Q.34 C Q.35 C Q.36 D Q.37 A Exercise 3(A) Q.1 C Q.2 A, D Q.3 A Q.4 C Q.5 A Q.6 D Q.7 A, C Q.8 D Q.9 A Q.10 D Q.11 C Q.12 B Q.13 B Q.14 A Q.15 B Q.16 D Q.17 A Q.18 B Q.19 B Q.20 B Q.21 D Q.22 A Exercise 3(B) 1 3 3 3 CH | CH CH C CH    2 heat KOH . alc          HBr 3 ) H C ( CH | CH CH C CH CH | H 12 6 3 2 2 3     4 5 6 (E) CH C CH || || CH CH 3 2 2   7 (a) (CH3–CH2) 3 CH CH CH | Br   ; (b) (CH3–CH2)2 Br | CH CH C | OH 3   ; (c) (C2H5)3C–OH 8 (X) Cl | CH CH C CH | | CH CH 3 3 3 3    ; (Y) 3 2 3 3 CH C C CH | | CH CH    ; (Z) 3 3 3 3 CH C C CH | | CH CH    10 (A) (B) 11 (A) CH3–CH2–CH=CH–CH2–CH3 (B) CH3CH2COOK 16 1 ozonolysis ; 2 LiAlH4 ; 3 H2SO4 17 (4)  HO–Cl ; (5)  CH3MgCl ; (6) H2O/H+

22. 19 (1) NaNH2, (2) Me–I, (3) HgSO4 dil H2SO4 20 higher electronegativityofsp carbon 21 (i) 6 2 3 2 3 3 H C O | CH CH C CH | CH     (ii) 23 (X)  Et–CC–Et (Y)  (Z)  Z is meso so opticallyinactive. 24. Bombykol :- HO–C–C–C–C–C–C–C–C–C–C=C–C=C–C–C–C (A) :- 4 geometricalisomers are possible 25 (a) 2 2 3 CH CH C CH | CH    (b) 26. (X) , (Y) O CH ) CH ( C CH | | O 4 2 3    

HYDROCARBON (13th).pdf

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