General Organic Chemistry Level-1 Past Paper PDF

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ꕯ 𝛼𝑚 𝞠𝙧⚈ https://t.me/studyzee https://t.me/studyzee  @unacademyplusdiscounts_link https://telegram.me/Unacademyplusdiscounts_link https://telegram.me/Unacademyplusdiscounts_link https://telegram.me/Unacademyplusdiscounts_link Join Us Now For all study Materials for free  1 1 GENERAL ORGANIC CHEMISTRY Level - 1 1. How many 2º Hydrogen atoms are present in the given following compound ? Cl (a) 2 (b) 5 (c) 7 (d) 8 2. Identify which functional group is Not present in the given following compound? O O NH O O (a) Ketone (b) Ester (c) Amide (d) Ether 3. Correct energy profile for amine inversion and hybridization of nitrogen in transition state is: N D H T H T D N (A) (B) https://t.me/studyzee  2 sp3 sp3 (a) (b) (B) (A) (B) (A) sp2 sp2 (c) (d) (A) (B) (A) (B) 4. (i) (ii) (iii) Correct order of the heats of combustion of above compounds is: (a) (i) > (ii) > (iii) (b) (i) > (iii) > (ii) (c) (ii) > (i) > (iii) (d) (ii) > (iii) > (i) 5. Which of the following is not a resonance structure of the others ? - O O - (a) (b) O O - (c) (d) - 6. Rank the hydrogen atoms (H a , H b , H c ) present in the following molecule in decreasing order of their acidic strength. Ha O O H2C CH3 Hb H H H c (a) a > b > c (b) b > a > c (c) b > c > a (d) c > b > a https://t.me/studyzee  3 O || 7. CH 3 — C — O — CH 3 ; a b The correct relation between the bond lengths a and b is: (a) a = b (b) b > a (c) b < a (d) Impossible to predict 8. The number of sp 2 - sp 2 sigma bonds in the compound given below is : (a) 1 (b) 3 (c) 4 (d) 5 9. The total number of lone pair of electrons in the given molecule is : O N—H (a) 2 (b) 3 (c) 4 (d) 5 10. Which of the following rings is highly strained ? O O O O (a) (b) d-lactone g-lactone O O (c) O (d) N –H b-lactone d-lactam 11. The functional groups present in Cortisone are : HOH2C CH3 OCH3 O Cortisone O (a) ether, alkene, alcohol (b) alcohol, ketone, alkene, ether (c) alcohol, ketone, amine (d) ether, amine, ketone 12. Select the acid with the highest K a (i. e. , lowest pK a ). O O O O Cl OH OH OH (a) H3C OH (b) Cl H (c) (d) Cl I https://t.me/studyzee  4 13. Most stable carbocation among the following is : CH3 (a) (b) CH2 Å (c) (d) CH 3 14. Arrange the following in increasing order of their pK a values. O O || || (x) CH 3 — S — O — H (y) CH 3 — C — O — H (z) CH 3 — OH || O (a) y < x < z (b) x < y < z (c) y < z < x (d) x < z < y 15. Which is the major product of the following reaction ? H N HCl ¾¾¾® Product 1 mole N | H Cl– H H H N N H (a) N (b) N Cl– | | H H Cl H H | N N Cl (c) (d) N N | H H 16. In the given pair identify most acidic compound in (A) and (B). Most basic in (C) and (D). CO2H CO2H CO2H CO2H CH3 CH3 (A) (B) (I) (II) (I) (II) NH2 NH2 NH2 NH2 CH3 CH3 (C) (D) (I) (II) (I) (II) (a) A - I, B - II, C - I, D - II (b) A - II, B - I, C - I, D - II (c) A - II, B - II, C - II, D - II (d) A - I, B - II, C - I, D - I https://t.me/studyzee  5 17. Several factors (steric, electronic, orbital interactions etc.) can affect the inversion barrier of an amine. In the given pair which data is correctly placed ? Me i – Pr | | N vs N Me Me i – Pr Me (a) + DG = 7.9 kcal/mol DG = 0.2 kcal/mol vs N N (b) Me Me DG = 20.5 kcal/mol DG = 7.0 kcal/mol Me Cl | | N vs N (c) Me Me Cl Cl + + + + DG = 7.9 kcal/mol DG = 22.9 kcal/mol (d) All of these 18. Select the response that correctly identifies the number of carbon atoms of each type of hybridization in the compound given below H 2C == C == CH — CH == O sp 3 sp 2 sp sp 3 sp 2 sp (a) 2 2 0 (b) 1 3 0 (c) 0 3 1 (d) 1 2 1 19. Circle represents most basic atoms in these molecule. Which of the following is correct representation ? N–N H N (a) N (b) N O H2N CN (c) (d) All of these H2N NH2 20. Circle represent most acidic hydrogens in these molecules. Which of the following is correct representation ? https://t.me/studyzee  6 O OH MeO2C OH HO (a) (b) CO2H CF3 S (c) (d) All of these F 21. Arrange the following in decreasing order of their acidic strengths. Å Å O N N | | OH | H H H CH3 (A) (B) (C) (D) (a) A > C > B > D (b) A > D > B > C (c) A > D > C > B (d) D > A > C > B 22. Cyclopropane Cyclobutane Cyclopentane (I) (II) (III) The correct order of heats of combustion of above compounds is : (a) I > II > III (b) II > I > III (c) III > II > I (d) III > I > II 23. (A) (B) (C) Compare carbon-carbon bond rotation across A, B, and C (a) A > B > C (b) A > C > B (c) B > A > C (d) B > C > A 24. Which of the following acids would have a STRONGER CONJUGATE BASE ? (A) H2S vs H2O 1 2 O O NH NH (B) vs O 3 4 (C) CH 3C ºº CH vs CH 3CH == CH 2 5 6 (a) 2, 4, 6 (b) 1, 3, 5 (c) 2, 3, 5 (d) 1, 3, 6 https://t.me/studyzee  7 KH 25. ¾® A ¾¾ ; Major products of the reaction is (are): -H 2 H 2O ¯ * 14 Major (C = C ) Product (a) (b) (c) (d) both (b)& (c) 26. Which of the following compound is most stable ? C9H19 C8H17 (a) (b) AcO AcO C8H17 C9H19 (c) (d) AcO AcO 27. Selected bond angles for six hydrocarbons are shown below. Arrange these hydrocarbons according to their pK a values, from the lowest to the highest. H H 128º 109.5º H H H H 115º H H H 108º H H H 117º (I) (II) (III) (IV) 180º H 120º H H H (V) (VI) (a) V < I < VI < II < III < IV (b) IV < I < II < III < V < VI (c) II < IV < I < VI < V < III (d) I < V < IV < III < II < VI 28. Which statement about the following equilibrium is true ? O¯ K+ + H2O OH + K+OH ¯ t-butoxide pKa = 15.7 pKa = 18 (a) The equilibrium favours the products (b) t-Butoxide is the dominant anionic species in the equilibrium https://t.me/studyzee  8 (c) Water is the weaker acid (d) t-Butoxide is stabilized by resonance 29. Consider the following reaction involving two acids shown below : formic acid and HF. O O K +F - + H OH H O-K+ + HF pK a = 3.2 pKa = 3.8 Which of the following statements about this reaction are true ? (A) Formic acid is the strongest Bronsted acid in the reaction (B) HF is the strongest Bronsted acid in the reaction (C) KF is the strongest Bronsted base in the reaction (D) KO2CH is the strongest Bronsted base in the reaction (E) The equilibrium favours the reactants (F) The equilibrium favours the products (G) Formic acid has a weaker conjugate base (H) HF has a weaker conjugate base (a) A, D and F (b) B, D, and H (c) A, C, and H (d) B, D, E and H 30. Which one of the following compounds has non zero dipole moment? OH CN ClCH2 CH2Cl NH (a) (b) (c) (d) HN ClCH2 CH2Cl HO NC CN 31. Which one of the following has the smallest heat of combustion ? CH3 CH3 CH3 CH3 (a) (b) (c) (d) H3C H3C H3C H3C C(CH3)3 C(CH3)3 C(CH3)3 C(CH3)3 32. Rank the following substances in order of decreasing heat of combustion (maximum ® minimum). CH3 CH3 CH3 CH3 CH3 1 2 3 4 (a) 1 > 2 > 4 > 3 (b) 3 > 4 > 2 > 1 (c) 2 > 4 > 1 > 3 (d) 1 > 3 > 2 > 4 33. Which of the following has lowest pK a value ? CH (a) (b) CH https://t.me/studyzee  9 (c) (d) 34. Arrange the following (w, x, y, z) in decreasing order of their boiling points: N O | N OH CH3 | H (w) (x) (y) (z) (a) w > x > z > y (b) w > x > y > z (c) w > z > y > x (d) w > z > x > y 35. Arrange the following in increasing order of their acidic strength. O O O O O O OCH3 (I) (II) (III) (IV) O O O (a) III < I < IV < II (b) II < I < IV < III (c) I < III < IV < II (d) II < III < I < IV 36. How many degrees of unsaturation are there the following compound ? OH O OH (a) 6 (b) 7 (c) 10 (d) 11 37. The heat of hydrogenation for 3-methylbutene and 2-pentene are –30 kcal/mol and –28 kcal/mol respectively. The heats of combustion of 2-methylbutane and pentane are – 784 kcal/mol and –782 kcal/mol respectively. All the values are given under standard conditions. Taking into account that combustion of both alkanes give the same products, what is DH (in kcal/mol) for the following reaction under same conditions ? (a) 0 (b) – 4 (c) – 2 (d) 2 https://t.me/studyzee  10 38. Which of the following s-bonds participate in hyperconjugation ? I V H H CH3 II H IV III (a) I and II (b) I and V (c) II and V (d) III and IV OH (y) HO (w) 39. OH HO (z) (x) Decreasing order of acidic strength of different (–OH) groups is : (a) w > x > y > z (b) w > z > x > y (c) z > w > x > y (d) z > x > w > y 40. Arrange the following alcohols in decreasing order of the ease of ionization under acidic conditions. O OH OH OH (I) (II) (III) (a) I > III > II (b) I > II > III (c) II > III > I (d) II > I > III 41. Among the isomeric amines select the one with the lowest boiling point. H | CH3 N | NH2 N (a) (b) NHCH (c) (d) 3 CH3 42. Which one of the compounds shown below, is not an isomer of the others ? (a) (b) (c) (d) https://t.me/studyzee  11 43. Arrange the anions (p) CH 3 , (q) NH 2 , (r) OH - , (s) F - , in decreasing order of their basic strength. (a) p > q > r > s (b) q > p > r > s (c) r > q > p > s (d) r > p > q > s 44. One among the following compounds will not give effervescence with sodium carbonate: OH SO3H NO2 NO2 (a) C 6H 5CO 2H (b) (c) C 6H 5OH (d) NO2 45. The carboxylic acid which has maximum solubility in water is: (a) phthalic acid (b) succinic acid (c) malonic acid (d) salicylic acid 46. Among the following compounds, the most basic compound is : (a) (b) N (c) (d) N N H O H H H x H z 47. y H H Arrange the (C – H) bonds x , y and z in decreasing order of their bond dissociation energies in homolysis. (a) y > x > z (b) z > x > y (c) z > y > x (d) y > z > x 48. 23 g of sodium will react with methyl alcohol to give : (a) one mole of oxygen (b) 22.4 dm 3 of hydrogen gas at NTP (c) 1 mole of H 2 (d) 11.2 L of hydrogen gas at NTP 49. Which of the following is most polar? Q (a) (b) (c) (d) Q 50. NH ; N–H; N; O (x) (y) (z) The correct order of decreasing basic strengths of x, y and z is : (a) x > y > z (b) x > z > y (c) y > x > z (d) y > z > x https://t.me/studyzee  12 51. Which of the following is the strongest Bronsted acid ? NH2 NH2 OH OH (a) (b) (c) (d) 52. Which of the following is the strongest Bronsted base ? NH2 H H H N N (a) (b) N (c) (d) H H 53. Which of the following is polar aprotic solvent ? (a) DMSO (b) Crown ether (c) DMG (d) All of these 54. Some pairs of acids are given below. Select the pair in which second acid is stronger than first (a) CH 3CO 2H and CH 2FCO 2H (b) CH 2FCO 2 H and CH 2ClCO 2H (c) CH 2ClCO 2H and CH 2BrCO 2H (d) CH 3CH 2CHFCO 2H and CH 3CHFCH 2CO 2H a b 55. H — C ºº C — C ºº C — CH 3 ; Compare the bond lengths a and b: (a) a = b (b) a > b (c) b > a (d) a >>> b 56. Which (isomeric) amine has lowest boiling point ? (a) 1º amine (b) 2º amine (c) 3º amine (d) cannot predict Cl 2SbCl 57. ¾¾¾ ¾5 ® P ; P will be : Cl (a) 2– (b) 2+ 2SbCl Q 6 (c) (d) mixture of (a) and (b) 58. Which of the following substances is not an isomer of 3-ethyl 2-methyl pentane ? (a) (b) (c) (d) All are isomers https://t.me/studyzee  13 59. Which of the following is an isomer of compound 1 ? O || CH 3CH 2CHO CH 3 — C — CH 3 CH 3 — CH == CH — OH CH2 — CH — CH3 (1) (2) ( 3) O (4) (a) 2 (b) 4 (c) 2 and 3 (d) all are isomers Br AgNO 3 60. ¾¾¾® (A) ; Which statement is incorrect in respect of the above reaction ? (a) Product is aromatic (b) Product has high dipole moment (c) Product has less resonance energy (d) Product is soluble in polar solvent 61. Some pairs of ions are given below. In which pair, first ion is more stable than second? Å Å (a) CH 3 — C H — CH 3 and CH 3 — C H — OCH 3 Å Å (b) CH 3 — CH 2 — C H — CH 3 and CH 2 == CH — CH 2 — C H 2 CH2 CH2 (c) and CH3 CH CH3 CH3 N CH3 (d) and CH2 C CH3 CH3 C CH3 62. Among the given pairs in which pair, first compound has higher boiling point than second ? (a) CH 3 — CH 2OCH 3 and CH 3 — C H — CH 3 | OH (b) CH 3 — CH 2 — CH 2 — CH 3 and CH 3 — CH 2 — CH 3 CH 2 — CH 3 | (c) CH 3 — CH 2 — CH 2 — CH 2 — CH 3 and CH 3 — CH — CH 2 — OH (d) CH 3 — CH 2 — CH 2 — CH 3 and CH 3 — CH 2 — CH 2 — Cl 63. Which of the following alcohols is the least soluble in water ? (a) Ethanol (b) 1-Propanol (c) 1-Butanol (d) 1-Pentanol 64. Which of the following alcohols is expected to have a lowest pK a value ? (a) Ethanol (b) 1-propanol (c) 2, 2, 2-trifluorethanol (d) 2-chloroethanol https://t.me/studyzee  14 65. Which of the following alkenes is the most stable ? (a) (b) (c) (d) 66. Bond X is made by the overlap of which type of hybridized orbitals ? X 3 2 (a) sp and sp (b) sp and sp (c) sp 2 and sp 3 (d) none of these 67. Increasing order of acidic strength of given compounds is : OH OH OH OH H3C NC H3CO (I) (II) (III) (IV) (a) III < I < IV < II (b) II < I < IV < III (c) I < III < IV < II (d) I < III < II < IV 68. COOH + NaHCO3 ¾¾® CO2 + COONa, C is with the product : (a) CO 2 (b) COONa (c) both (d) none of these 69. Rank in the order of increasing acidity. (I) OH (II) NH2 (III) OH (a) III < I < II (b) I < III < II (c) III < II < I (d) II < I < III 70. Which compound has the highest value of pK a ? (a) Cl — CH 2 — CH 2 — COOH (b) CH 3 — CH 2 — COOH Cl | (c) CH 3 — C H — COOH (d) CH 3 — C — COOH | | Cl Cl 71. Consider the hydrogen atoms attached to three different carbon atoms (labeled 1, 2 & 3). Rank the attached hydrogen atoms in order from most acidic to least acidic. O O 3 O 1 2 (a) 2 > 1 > 3 (b) 1 > 2 > 3 (c) 2 > 3 > 1 (d) 3 > 2 > 1 https://t.me/studyzee  15 72. Decreasing order of acidic strengths of following compounds is : H CN (x) (y) (z) (a) x > y > z (b) y > x > z (c) z > y > x (d) z > x > y 73. Among the given pairs, in which pair second compound is more acidic than first ? O O || || (a) BrCH 2NO 2 and CH 3CH 3 (b) CH 3 — C CH 2CN and CH 3 — C — CH 3 OH OH OH OH (c) & (d) & CH3 — C == O CH3 74. Which of the underlined atoms in the molecules shown below have sp-hybridization ? (u) CH 2CHCH 3 (v) CH 2 CCHCl (w) CH 3 CH 2+ (x) H — C ºº C — H (y) CH 3 CN (z) (CH 3 ) 2 CNNH 2 (a) x and z (b) x, y, and z (c) u, w and x (d) v, x and y 75. Which of the following, is the product of the reaction between AlCl 3 and CH 3OCH 3 ? Cl Cl | CH3 | CH3 (a) Cl — Al — O (b) Cl — Al — O | CH3 | CH3 Cl Cl Cl Cl | CH3 | (c) Cl — Al — O (d) Cl — Al — CH3OCH3 | CH3 | Cl Cl 76. Which of the following compounds contain at least one secondary alcohol ? H OH OH OH O OH OH HO H HO CH3 HO H O HO CH3 H H (I) (II) (III) (IV) (V) (VI) (a) I, II, IV, VI (b) I, III (c) I, II, III, V (d) I, III, V https://t.me/studyzee  16 77. Which of the following has the most negative heat of hydrogenation ? (a) (b) (c) (d) 78. Which of the following options is the correct order of relative stabilities of cations I, II and III as written below (most stable first) ? + CH 3 CH2 + | + (I) (II) H 2C == CH — CH 2 — C H — CH 3 (III) H 3C — C — C H 2 | CH 3 (a) I > II > III (b) II > III > I (c) III > I > II (d) I > III > II 79. What is the decreasing order of stability (most stable ® least stable) of the following carbocations ? + + + + + 1 2 3 4 5 (a) 3 > 2 > 1 > 4 > 5 (b) 3 > 2 > 5 > 4 > 1 (c) 1 » 4 > 2 » 5 > 3 (d) 3 > 1 » 4 > 2 » 5 H 80. the hydrogen indicated by arrow will be easily removed as : (a) H + (b) H Q (c) H · (d) H -2 81. Rank the bond dissociation energies of the bonds indicated with the arrows. (from smallest to largest). H 1 | 2 CH2 H 3 H (a) 1 < 2 < 3 (b) 3 < 2 < 1 (c) 2 < 3 < 1 (d) 3 < 1 < 2 82. Rank the following compounds in order of decreasing acid strength (most acidic ® least acidic). OH OH OH OH NO2 NO2 1 2 3 4 (a) 2 > 4 > 1 > 3 (b) 1 > 3 > 4 > 2 (c) 3 > 1 > 2 > 4 (d) 3 > 1 > 4 > 2 https://t.me/studyzee  17 83. Rank the following compounds in order of increasing acidity (weakest acid first). Cl CH3 NO2 Cl OH H3C OH O2N OH Cl CH3 NO2 1 2 3 (a) 2 < 3 < 1 (b) 3 < 1 < 2 (c) 1 < 2 < 3 (d) 2 < 1 < 3 84. Which of the following phenols has the largest pK a value (i. e. , is least acidic) ? (a) Cl OH (b) O2N OH (c) H3C OH (d) N C OH 85. Among the given sets, which represents the resonating structures ? (a) H — C ºº N — O and H — O — C ºº N (b) H — O == C == N and H — O — C ºº N O (c) H — C ºº N — O and H — C — N (d) H — O — C ºº N and H — N == C == O 86. Identify each species in the following equilibrium according to the code : SA = stronger acid ; SB = stronger base ; WA = weaker acid ; WB = weaker base. The pK a of (CH 3 ) 2 NH is 36 ; the pK a of CH 3OH is 15.2. + CH 3OH + (CH 3 ) 2 NH 1 2 º CH 3 — O - + CH 3 — NH — CH 3 | H 1 2 1 2 1 2 1 2 (a) WA WB (b) WB WA (c) SA SB (d) SB SA (e) WA WA 87. The hydrogen bonding is strongest in which one of the following set ? (a) F — H - - - F (b) O — H - - - S (c) S — H - - - F (d) F — H - - - O 88. Intermolecular hydrogen bonding is strongest in : (a) methylamine (b) phenol (c) formaldehyde (d) methanol O d O a O–H 89. H SH OH OH c b https://t.me/studyzee  18 Identify most acidic hydrogen in given compound. (a) a (b) b (c) c (d) d 90. Which of the following compounds would you expect to be strongest carbon acid ? O O O (a) (b) O (c) CH2(CO2Et)2 (d) CH3COCH2COOC2H5 91. 5-Bromo-2-cyclopropyl cyclohex-2-enol have correct structure is: Br OH (a) (b) HO Br OH Br (c) (d) Br OH 92. Rearrange the following in the increasing order of acidic strength. (i) benzoic acid (ii) p-methoxybenzoic acid (iii) o-methyoxybenzoic acid (a) i < ii < iii (b) iii < i < ii (c) ii < i < iii (d) iii < ii < i 93. In the following acid-base reaction, in which can backward reaction if favoured? (a) EtO + OH (b) KH + EtOH O (c) Me3CO + H 2O (d) + CH3OH 94. Which compound posses highest dipole moment ? (a) naphthalene (b) phenanthrene (c) anthracene (d) azulene H2 H2 2H 95. ¾ ¾¾® catalyst ¾(E ¾¾ ) ® ¾(E ¾¾ ) ® 2 3 (E1 ) (E = activation energy) Relation between activation energies of above reactions is : (a) E 2 > E 1 > E 3 (b) E 3 > E 1 > E 2 (c) E 3 > E 2 > E 1 (d) E 1 > E 2 > E 3 https://t.me/studyzee  19 96. Rank the following solvents in decreasing order of ability to dissolve given compound. Solvent Et2O H2O ¾® EtOH Solute (a) Et 2O > H 2O > EtOH (b) H 2O > EtOH > Et 2O (c) H 2O > Et 2O > EtOH (d) Et 2O > EtOH > H 2O Me2N: :NMe2 97. 1, 8-Bis (dimethylamino) naphthalene is after referred so as (Proton sponge) Its basic strength is 1010 more than 1-dimethyl amino naphthalene. Reason for high basic strength is : (a) resonance (b) steric inhibitation of resonance (c) ortho effect (d) hyperconjugation 98. In the given pair of compounds, in which pair second compound has higher boiling point than first compound ? (a) OH and O (b) O and (c) HO — CH 2 — CH 2 — OH and CH 3 — CH 2 — CH 2 — OH CH3 | N NH (d) and Me Me Me Me N N Me Me 99. , ; Dipole moments of given compound will be : Me Me NO2 NO2 (A) (B) (a) (A) = 6.87D, (B) = 4.11D (b) (A) = 4.11 D , (B) = 6.87 D (c) (A) = 4.11 D , (B) = 4.11 D (d) (A) = 6.87 D, (B) = 6.87 D 100. Order of decreasing basic strengths of halides is : (a) F - > Cl - > I - > Br - (b) F - > Cl - > Br - > I - - - - - (c) I > Br > Cl > F (d) I - > Cl - > Br - > F - https://t.me/studyzee  20 101. Among the xylenes, which is thermodynamically most stable ? (a) (b) (c) (d) All are equally stable 102. Heat of combustion of two isomer x and y are 17 kJ/mol and 12 kJ/mol respectively. From this information it may be concluded that : (a) isomer x is 5 kJ /mol more stable (b) isomer y is 5 kJ/mol less stable (c) isomer y has 5 kJ/mol more potential energy (d) isomer x is 5 kJ/mol less stable 103. Rank the following substances in decreasing order of heat of combustion (most exothermic ¾® least exothermic) (A) (B) (C) (a) B > A > C (b) A > B > C (c) C > A > B (d) C > B > A 104. (1) (2) (3) (4) Choose the statement that best describes given compounds. (a) 1, 3, 4 represent same compound (b) 1 and 3 are isomer of 2 and 4 (c) 1, 4 are isomer of 2 and 3 (d) All the structure represent the same compound 105. Decreasing order of acid strengths is : Å Ph — OH , Ph — CH 2 — OH , Ph — CO 2H , Ph — CH 2 — N H 3 (A ) ( B) (C) (D ) (a) B > A > C > D (b) C > A > B > D (c) C > A > D > B (d) C > B > A > D 106. Rank the following in decreasing order of basic strength is : (A) CH 3 — CH 2 — C ºº C - (B) CH 3 — CH 2 — S - (C) CH 3 — CH 2 — CO -2 (D) CH 3 — CH 2 — O - (a) B > A > D > C (b) D > A > B > C (c) A > D > B > C (d) A > D > C > B https://t.me/studyzee  21 107. Among the given compound choose the two that yield same carbocation on ionization. Br Br Br Br (A) (B) (C) (D) (a) A, C (b) B, D (c) A, B (d) B, C 108. Oxalic acid pK 1 Malonic acid pK 2 Heptanedioic acid pK 3 where pK 1 , pK 2 , pK 3 are first ionization constants. Correct order is : (a) pK 1 > pK 2 > pK 3 (b) pK 1 < pK 2 < pK 3 (c) pK 3 > pK 2 = pK 1 (d) pK 3 > pK 1 > pK 2 109. In sets a – d, only one of the set is incorrect regarding basic strength. Select it : NH2 (a) Ph — NH — Ph 1 < Ph — NH 2 < (strong base) H | N (b) N < < | N H NH2 NH2 NH2 N (c) > > (d) < < N N | | N H H NO2 CH3 110. Dipole moment of which ketone is maximum ? O O (a) (b) (c) (d) O O 111. Correct order of basic strengths of given amines is : (a) Me 2NH > MeNH 2 > Me 3N > NH 3 (Protic solvent) 2° 1° 3° (b) Et 2NH > Et 3H > EtNH 2 > NH 3 (Protic solvent) 2° 3° 1° (c) Me 3N > Me 2NH > Me - NH 2 > NH 3 (Gas phase) (d) All are correct https://t.me/studyzee  22 NH2 CH3 112. Order of basic strength Ph — NH 2 , Ph — NH — Me , Ph — N — Me, (A) (B) | Me (C) (D) (a) A > B > C > D (b) B > A > C > D (c) C > B > A > D (d) C > B > D > A 113. Carbon-carbon double bond length will be maximum in which of the following compounds ? (a) CH 3 — CH == CH 2 (b) CH 3 — CH == CH — CH 3 (c) CH 3 — C == C — CH 3 (d) CH 2 == CH 2 | | CH 3 CH 3 114. Which has maximum dipole moment ? (a) (b) O || O C || C (c) (d) N 115. (i) Et 3N (ii) (iii) N N Compare the basic strengths of compounds given: (a) (i) > (ii) > (iii) (b) (ii) > (i) > (iii) (c) (ii) > (iii) > (i) (d) (iii) > (ii) > (i) 116. For the following two reactions, which statement is true ? E E reactants reactants products products Reaction A Reaction B (a) Reaction A is faster and less exergonic than B (b) Reaction B is faster and more exergonic than A (c) Reaction A is faster and less endergonic than B (d) Reaction B is faster and more endergonic than A https://t.me/studyzee  23 a O Å b H 117. ¾¾¾® c N d | CH3 Identify the site, where attack of H + is most favourable. (a) a (b) b (c) c (d) d 118. Rank the following alkenes on order of increasing l max. (1) (2) (3) (a) 1 < 2 < 3 (b) 1 < 3 < 2 (c) 2 < 1 < 3 (d) 2 < 3 < 1 119. Which of the following cyclic amine has lowest DG# for inversion ? (a) N – CH3 –Me (b) N – n-Bu (c) N – t-Bu (d) N – Ph 120. Rank in the order of increasing acidic strength: O O CO2Et EtO2C CO2Et CO2Et O O CO2Et (A) (B) (C) (a) A < B < C (b) A < C < B (c) B < A < C (d) B < C < A 121. Which one of the following dienes would you expect to be the most stable ? (a) (b) (c) (d) 122. Which metal catalyzed reaction would release the maximum amount of heat per CH2 unit ? (a) cyclopropane + H 2 ® propane (b) cyclobutane + H 2 ® butane (c) cyclopentane + H 2 ® pentane (d) cyclohexane + H 2 ® hexane O O O – 123. (A) (B) (C) – – Compare basic strengths of the above compounds: (a) A > B > C (b) B > A > C (c) C > A > B (d) C > B > A https://t.me/studyzee  24 124. On reaction with acid, 4-pyrone gives a very stable cationic product. Which of the following structures shows the protonation site in that product ? O 4-Pyrone O O H O O ÅO H Å H Å (a) Å (b) H (c) (d) O O O H O H 125. Which of the following is the most stabilized carbocation ? OMe OMe OMe OMe Å Å Å (a) (b) Å (c) (d) 126. Which carbocation is the most stable ? (a) (b) Å Å Å (c) (d) Å 127. Consider a positively charged C 2H 3 species in which the positively charged carbon is sp - hybridized, the uncharged carbon is sp 2 -hybridized and an empty p-orbital is perpendicular to the p system. What it the best description of this cation ? (a) vinyl (b) allenyl (c) alkyl (d) allyl 128. Which of the following reactions is not exothermic ? (a) CH3 — Cl + CH3 — CH3 ¾® CH4 + CH3 — CH2 — Cl (b) CH3 — Cl + (CH3)3 C — H ¾® CH4 + (CH3)3 C — Cl (c) CH3 — Cl + CH2 == CH — CH3 ¾® CH4 + CH2 == CH — CH2 — Cl (d) CH3 — Cl + CH2 == CH2 ¾® CH4 + CH2 == CHCl 129. List the following carbocations in order of decreasing stabilization energies. + + + + (I) (II) (III) (IV) (a) II, III, I, IV (b) III, IV, II, I (c) III, IV, I, II (d) I, II, IV, III 130. For the following two acid-base reactions, which statement is true ? (I) CH 3CH -2 + CH 3NH 2 CH 3CH 3 + CH 3NH - pK a =35 pK a =50 (II) F - + H 2O HF + HO - pK a = 15.7 pK a =3.2 https://t.me/studyzee  25 (a) I is favoured to the right, II is favoured to the left (b) I is favoured to the left, II is favoured to the right (c) I is favoured to the right, II is favoured to the right (d) I is favoured to the left, II is favoured to the left 131. Rank the hydrogen atoms (H a , H b , H c ) in the following molecules according to their acidic strengths: Ha Hc Hb (a) a > b > c (b) b > a > c (c) b > c > a (d) a > c > b 132. In which of the following reactions, backward reaction is favoured ? (a) H — C ºº C — H + Li+ –CH2CH3 H — C ºº C :Q Li+ + H3C — CH3 O O (b) + –OCH2CH3 - + HOCH2CH3 F 3C OH F3C O: : : + Å (c) CH 3CH 2 SH 2 + CH 3CH 2OH && - H CH 3CH 2SH + CH 3CH 2 O | H + + NH3 OH NH2 OH2 (d) + + 133. Which carbocation is the most stabilized ? Å (a) (b) (c) Å (d) Å Å 134. Taking into account of hybridization and resonance effects, rank the following bonds in order of decreasing bond length. :O: (I) (II) : O : : O : : (III) (a) I > II = III (b) II > III > I (c) I > III > II (d) II = III = I 135. Which one among the following carbocations has the longest half-life ? + + (a) C (b) C https://t.me/studyzee  26 + + (c) C (d) CH 3 — C — CH 3 | CH 3 136. Rank the following alkenes in order of decreasing heats of hydrogenation (largest first) 1 2 3 4 (a) 2 > 3 > 4 > 1 (b) 2 > 4 > 3 > 1 (c) 1 > 3 > 4 > 2 (d) 1 > 4 > 3 > 2 137. Which of the following reactions is most exothermic ? hv hv (a) + Cl2 ¾¾ ® Cl + HCl (b) + Br2 ¾¾ ® Br + HBr hv hv (c) + Cl2 ¾¾ ® Cl + HCl (d) + Br2 ¾¾ ® Br + HBr 138. Which energy diagram best represents the given reaction ? CH3 hn H3C H3C CH3 E E E E (a) (b) (c) (d) 139. Which one of the following is most stable ? H Br H Br H Br Br H H H H H H H H (a) (b) + (c) (d) H + + H H H H H H H H :NH2 :NH2 +NH :NH2 2 140. Which of the following is strongest acid ? H H + N –H (a) H - N +- H (b) H H H H +H + N N (c) (d) https://t.me/studyzee  27 141. Compare relative stability of the following resonating structure. O O– O (i) (ii) (iii) C C C N N N (a) (i) > (ii) > (iii) (b) (ii) > (i) > (iii) (c) (i) > (iii) > (ii) (d) (ii) > (iii) > (i) 142. Compare relative stability of the following resonating structure. O O O (p) CH3 (q) (r) C N N N (a) p > q > r (b) q > p > r (c) q > r > p (d) p > r > q 143. Which of the following isomeric hydrocarbons is most acidic ? (a) (b) (c) (d) 144. Which of the following has the lowest barrier to rotation about the indicated bond ? (a) (b) (c) (d) 145. Use the following data to answer the question below. H2 ( DH = - 28.6 kcal mol -1 ) Ni excess H2 (Ni) ( DH = - 116.2 kcal mol -1 ) Anthracene Calculate the resonance energy of anthracene: (a) 84 kcal mol (b) 100 kcal mol (c) 110 kcal mol (d) 116 kcal mol 146. How many double bond equivalents does a compound of molecular formula C 6 H 12O 6 possess? (a) 0 (b) 1 (c) 2 (d) 3 https://t.me/studyzee  28 147. How many double bond equivalents does amoxycillin (shown below) possess ? NH2 H N S O N HO O amoxycillin CO2H (a) 5 (b) 6 (c) 7 (d) 9 148. What is the oxidation state of osmium in 7B and 7C, respectively ? O O O O + Os Os O O O O 7A 7B 7C (a) 6, 8 (b) 8, 6 (c) 6, 6 (d) 8, 8 O O Ha Hb 149. N N Hc | Hd | H He Identify most acidic hydrogen present in the above compound: (a) a (b) b (c) c (d) d 150. Which of the following compounds has most acidic hydrogen ? O S (a) CH (b) CH O S H | N O (c) CH (d) CH N N | H H 151. Acetic acid, (CH3COOH), has a pK a of 4.8. Ethanol, (CH 3CH 2OH), has a pK a of 16.0. What are the major species present, when acetic acid and ethanol are added to water and the pH is adjusted to 7.0 ? (a) CH 3CO 2H and CH 3CO 2OH (b) CH 3CH 2O - and CH 3CH 2OH (c) CH 3CO 2H and CH 3CH 2O - (d) CH 3CO -2 and CH 3CH 2OH 152. O https://t.me/studyzee  29 The most stable canonical structure of given molecule is: Q Q Q Å Å O O O Å O (a) (b) Q (c) Å (d) 153. In the potential energy diagram to the right, the point X represents : Potential energy X W Y Electronic Reorganization (a) a transition state (b) a reaction intermediate (c) a resonance hybrid (d) a reactant 154. CH3 CH2 (I) (II) (III) Which of the following orders is correct for heat of hydrogenation of these compounds ? (a) I > III > II (b) III > II > I (c) III > I > II (d) II > I > III CH3 CH2 CH3 155. CH3 CH3 CH3 (I) (II) (III) Which of the following orders is correct for heat of hydrogenation of these compounds ? (a) I > II > III (b) III > II > I (c) II > III > I (d) III > I > II Å Q Q Å 156. CH 2 == O ¬¾® CH 2 — O ¬¾® CH 2 — O (I) (II) (III) Which of these structures is practically not a valid canonical structure for formaldehyde ? (a) I (b) II (c) III (d) None of these 157. CH 2 == CH — CH == CH — ÅNH 3 ; Å CH 2 —CH ==CH — Q CH — Å NH 3 (I) (II) Å CH 2 — CH == CH — CH == NH 3 (III) Which of these structures is not a valid canonical structure ? (a) I (b) II (c) III (d) none of these https://t.me/studyzee  30 O OQ O?Q || | | 158. C ¬® C ¬® C Q Å Q H CH2 H CH2 H CH2 (I) (II) (III) The correct order of stability for the given canonical structures is : (a) I > III > II (b) III > I > II (c) II > III > I (d) II > I > III Å O O O Å 159. Å (I) (II) (III) The most stable canonical structure among the given structure is : (a) I (b) II (c) III (d) all are equally stable 160. OCH3 OCH3 (I) (II) OCH3 (III) For the given compounds the correct order of resonance energy is : (a) III > I > II (b) II > I > III (c) I > II > III (d) III > II > I O–H Å OH OH || CH3 | CH3 | Å CH3 161. CH3 – C – N CH3 – C – N CH3 – C = N Å CH3 CH3 CH3 (I) (II) (III) The correct stability order of the given canonical structures is : (a) I > II > III (b) III > I > II (c) I > III > II (d) II > III > I O 162. In the above compound, how many sites are available for the attack of CH 3O - ? (a) 1 (b) 2 (c) 3 (d) 4 163. CH2 == CH2 CH3O – CH == CH2 CH3O – CH == CH – C – OEt || (I) (II) O (III) Which of the following orders of rotation barrier about the C = C bond, as indicated, is correct ? (a) I > II > III (b) III > II > I (c) III > I > II (d) II > I > III https://t.me/studyzee  31 164. CH CH2 CH CH (I) (II) CH CH OCH3 (III) Which of the following orders of rotation barrier about the C == C bond, as indicated, is correct? (a) I > II > III (b) III > II > I (c) III > I > II (d) II > I > III 165. Which of the following compound is not resonance stabilized ? s O s (a) (b) (c) (d) O O s O 166. Homologous compound have same: (a) General formula (b) Emperical formula (c) Structural formula (d) Molecular formula 167. Most acidic is: OH OH OH OH (a) (b) (c) (d) NO2 CH3 NO2 168. Which of the following substituents will decrease the acidic strength of phenol? (a) —NO 2 (b) —CN (c) —CH 3 (d) —CHO 169. Which of the following structures possesses a cross-conjugated system? (a) CH 2 == CH — CH == CH — CH 2 (b) CH 2 == CH — C == CH 2 | CH 2CH 3 (c) CH 2 == CH — CH — CH == CH 2 (d) CH 2 == CH — C == CH 2 | | CH == CH 2 CH == CH2 170. Examine the following resonating structures of formic acid for their individual stability and then answer the question given below. O O– O– O+ + + – H—C—OH¬¾®H—C== O—H¬¾®H—C—OH¬¾®H—C—OH I II III IV Which of the following arrangements gives the correct order of decreasing stability of the above-mentioned resonance contributors? (a) II > I > III > IV (b) I > II > III > IV (c) IV > III > I > II (d) IV > III > I > II https://t.me/studyzee  32 171. Which of the following is not resonating structure of each other? (a) CH 3 — N == C == S and CH 3 — S — C ºº N + + (b) CH 3 — C == O and CH 3 — C ºº O O O- || | + (c) CH 3 — C — OH and CH 3 — C == O — H + (d) CH 2 == CH — C ºº N and CH 2 — CH == C == N - 172. In the molecule CH 3C ºº CCH == CH 2 , the maximum number of carbon atoms arranged linearly is: (a) 2 (b) 3 (c) 4 (d) 5 173. The stability order of the following carbocations is: + + + + I II III IV (a) II > IV > III > I (b) IV > II > III > I (c) II > III > I > IV (d) I > III > II > IV 174. Total number of a-hydrogen in given compound is: (a) 4 (b) 5 (c) 6 (d) 7 175. In which pair second ion is more stable than first? s r OH CH3 r r r s r s (i) (ii) (iii) (iv) (a) (i) and (ii) (b) (ii) and (iii) (c) (ii) and (iv) (d) (iii) and (iv) 176. Which one is the most stable cation in the following ? OH OH OH OH r r (a) (b) (c) (d) r r https://t.me/studyzee  33 177. The most reactive amine towards dilute hydrochloric acid is ________. CH2NH2 CONH2 NH2 : NH (a) (b) (c) (d) : N H 178. How many resonance structures are there for anthracene ? (a) 6 (b) 5 (c) 4 (d) 2 179. Which base is strong enough to convert (CH 3 ) 3 COH into (CH 3 ) 3 CONa in a reaction that goes to completion ? (a) NaNH 2 (b) CH 3CH 2Na (c) NaOH (d) CH 3CO 2Na (e) More than one of the above 180. Based upon an understanding of product stability, predict the product formed when the following dianion reacts with one equivalent of acid Os Os Hr s Os OH OH O (a) (b) Os O s O O (c) (d) O sO (e) 181. Rank the following alkyl radicals in order of increasing stability (least < < < most). Ph 1 2 3 4 (a) 4 < 2 < 1 < 3 (b) 3 < 1 < 2 < 4 (c) 1 < 3 < 4 < 2 (d) 2 < 4 < 3 < 1 182. Among the given cations, the most stable carbonium ion is ? (a) sec-butyl (b) tert-butyl (c) n-butyl (d) None of these https://t.me/studyzee  34 183. Cyclohexadiene contains ____ vinylic and _____ allylic hydrogen atoms ? (a) 2 and 2 respectively (b) 4 and 4 respectively (c) 2 and 4 respectively (d) 4 and 2 respectively 184. The dipole moments of halo compounds are in the order (a) CHCl 3 > CCl 4 > CHCl 2 > cis - CHCl = CHCl (b) cis - CHCl = CHCl > CHCl 3 > CH 2Cl > CCl 4 (c) cis - CHCl = CHCl > CH 2Cl 2 > CHCl 3 > CCl (d) CHCl 3 > CHCl 2 > cis - CHCl = CHCl > CCl 4 185. The pka value in H 2O of picric acid, acetic acid and phenol are in the order : (a) Picric acid 0.4, acetic acid 4.75, phenol 10.0 (b) Acetic acid 0.4, picric acid 4.75, phenol 10.0 (c) Picric acid 0.4 phenol 4.75, acetic acid 10.0 (d) Phenol 0.4, acetic acid 4.75 picric acid 10.0 186. The preferred sites of protonation in the following compounds are: O1 CH3 NHCH3 2 N NH2 3 4 (i) (ii) (a) 1 and 3 (b) 2 and 4 (c) 1 and 4 (d) 2 and 3 187. Among i-iii OH OH OH OH OH (i) (ii) (iii) the boiling point follows the order (a) (ii) < (i) < (iii) (b) (iii) < (ii) < (i) (c) (i) < (ii) < (iii) (d) (ii) < (iii) < (i) 188. The number of C — C sigma bonds in the compound O (a) 16 (b) 14 (b) 18 (d) 11 189. The correct order of dipole moment for the following molecules is F F F F F F F F Cl F (I) (II) (III) (IV) (a) IV > I > III > II (b) I > IV > III > II (c) III > I > II > IV (d) II > III > IV > I https://t.me/studyzee  35 190. Curved arrows are used in Organic Chemistry to show the movement of electrons in the mechanism of a reaction. The correct product of the following reaction is O O O O O (a) (b) (c) H (d) 191. Which of the following will form carbocation most readily ? O O HClO4 HClO4 (a) (b) O Cl OH HClO4 AlCl3 (c) (d) 192. Observed heat of hydrogenation for cyclohexa-1,4-diene and cyclo hexa-1,3-diene is x & y kcal/mol respectively, calculate the resonance energy of cyclohexa-1,3-diene : 3x 2x (a) -y (b) -y 2 2 3y 2y (c) -x (d) -x 2 2 https://t.me/studyzee  36 ANSWERS – LEVEL 1 1. (c) 2. (d) 3. (d) 4. (a) 5. (d) 6. (d) 7. (b) 8. (c) 9. (b) 10. (c) 11. (b) 12. (b) 13. (a) 14. (b) 15. (b) 16. (b) 17. (d) 18. (c) 19. (d) 20. (d) 21. (c) 22. (c) 23. (c) 24. (a) 25. (d) 26. (d) 27. (d) 28. (a) 29. (d) 30. (a) 31. (c) 32. (c) 33. (d) 34. (d) 35. (d) 36. (d) 37. (b) 38. (b) 39. (a) 40. (c) 41. (c) 42. (d) 43. (a) 44. (c) 45. (c) 46. (d) 47. (b) 48. (d) 49. (b) 50. (b) 51. (d) 52. (d) 53. (d) 54. (a) 55. (c) 56. (c) 57. (b) 58. (b) 59. (d) 60. (c) 61. (b) 62. (b) 63. (d) 64. (c) 65. (d) 66. (c) 67. (a) 68. (a) 69. (d) 70. (b) 71. (a) 72. (d) 73. (d) 74. (d) 75. (a) 76. (d) 77. (a) 78. (a) 79. (b) 80. (a) 81. (d) 82. (d) 83. (d) 84. (c) 85. (b) 86. (a) 87. (a) 88. (b) 89. (a) 90. (d) 91. (b) 92. (c) 93. (d) 94. (d) 95. (d) 96. (d) 97. (b) 98. (d) 99. (a) 100. (b) 101. (b) 102. (d) 103. (a) 104. (a) 105. (c) 106. (c) 107. (c) 108. (b) 109. (c) 110. (c) 111. (d) 112. (c) 113. (c) 114. (c) 115. (c) 116. (a) 117. (a) 118. (d) 119. (c) 120. (c) 121. (c) 122. (a) 123. (c) 124. (c) 125. (d) 126. (b) 127. (a) 128. (d) 129. (b) 130. (a) 131. (c) 132. (d) 133. (c) 134. (d) 135. (a) 136. (d) 137. (c) 138. (d) 139. (c) 140. (c) 141. (a) 142. (d) 143. (b) 144. (c) 145. (a) 146. (b) 147. (d) 148. (b) 149. (a) 150. (b) 151. (d) 152. (b) 153. (a) 154. (a) 155. (c) 156. (c) 157. (c) 158. (b) 159. (c) 160. (c) 161. (b) 162. (c) 163. (a) 164. (a) 165. (c) 166. (a) 167. (d) 168. (c) 169. (d) 170. (b) 171. (a) 172. (c) 173. (c) 174. (c) 175. (b) 176. (b) 177. (c) 178. (c) 179. (e) 180. (d) 181. (c) 182. (b) 183. (b) 184. (c) 185. (a) 186. (a) 187. (a) 188. (b) 189. (b) 190. (c) 191. (c) 192. (b) https://t.me/studyzee  37 Level - 2 1. Rank in order of radical stability (1 = most stable). (a) (b) (c) (d) * * * * 2. Predict the acidity order for the three phenols shown below : Acidity order : 1 (most) to 3 (least) OH OH OH (a) (b) (c) Me Me Me O || O Acidity order :.................................. 3. Comprehension OH OH OH O2N NO2 (A) (B) (C) NO2 NO2 CH3 OH OH OH H2N NH2 (D) (E) (F) NO2 C NH2 O CH3 https://t.me/studyzee  38 A. Which of the phenol derivatives above is the strongest acid ? * Compound A * Compound B * Compound C * Compound D * Compound E * Compound F B. Which of the phenol derivatives above is the weakest acid ? * Compound A * Compound B * Compound C * Compound D * Compound E * Compound F C. Which of the mono-nitrophenol derivatives above is the strongest acid ? * Compound A * Compound D D. Which of the carbon-substituted phenol derivatives above is the strongest acid ? * Compound C * Compound F 4. The following questions refer to the twelve compounds given below. You may enter as many as six choices in each answer box. O (a) (b) (c) H3C N O — C2H5 OH CH3 (d) H —F (e) CH3 (f) CH3 O O (g) (h) O (i) O—H NH2 O (j) (k) H3C (l) N O A. Which compound may serve only as H-bond donors ? B. Which may serve both as H-bond donors and acceptors? C. Which compounds will not participate in H-bonding ? 5. Consider the following compounds and answer A and B. (I) (II) (III) (IV) N N O O O O N O | | | H H H A. Which of the compounds is the strongest Bronsted acid ? (a) I (b) II (c) III (d) IV https://t.me/studyzee  39 B. Which of the compounds is the strongest Lewis base ? (a) I (b) II (c) III (d) IV 6. Rank the non-bonding electrons indicated by the arrows in order of increasing energy. B C H3C.. – A N.. H3C –.. N — CH3 N O 7. In each of the following sections four nitrogen containing compounds are listed. In the box under each formula write a number (1 to 4) indicating the order of base strength. N—H (a) N — CH3 O2N NH2 N O O N—H NH2 O2N NH2 N—H (b) O N—H N(CH3)2 N—H N N—H N — CH3 (c) H H3C N—H C ºº N