Test Date: (Sunday) Test Time: 2:00 pm to 3:30 pm Test Venue: Lajpat Bhawan, Madhya Marg, Sector 15-B, Chandigarh

Transcription

1 Test Date: (Sunday) Test Time: :00 pm to :0 pm Test Venue: Lajpat hawan, Madhya Marg, Sector 15-, handigarh Dr. Sangeeta Khanna Ph.D 1 EMISTRY ING IRLE

2 LEVEL II (Test Dated: ) 1. The test is of 1 hour 0 minutes duration.. The maximum marks are This test consists of 41 questions. RED INSTRUTINS REFULLY SETIN (Single orrect hoice Type) Negative Marking [-1] This Section contains 8 multiple choice questions. Each question has four choices ), ), ) and D) out of which NLY NE is correct. Marks: 8 4 = 1. rrange the following in decreasing order of E reaction: a. X > Y > Z b. X > Z > Y c. Z > X > Y d. Y > X > Z s the number of anti H and increases E reaction increases. (X) (Y) (Z). Na Product: a. b. c. d. No reaction D H and are not anti position. (II) (III). (IV) (I) Which omine is most reactive for SN attack of ion a. I b. II c. III d. IV (III) (II) (IV) (I) [electron withdrawing group increases Reactivity in SN ] Dr. Sangeeta Khanna Ph.D EMISTRY ING IRLE

3 4. mong the following the most reactive towards alcoholic KH is a. = b. c. d. In, the -hydrogen is more acidic due to electron-withdrawing effect of the = group, therefore, it can be easily abstracted by a base. Further, the product formed is stabilized by resonance due to conjugation of the double bond with the = group. Thus is most reactive towards alcoholic KH KH(alc.) H 5. H = H Major product: a. H b. H c. H d. H = 6. Match the column I with column II olumn I NaNH in liq.nh () cis--utene () trans--utene (D) p-nitrochlorobenzene q. KH olumn II () hlorobenzene (p) meso-, -Dibromobutane (q) enzyne mechanism (r) imolecular mechanism (s) (±)-, -Dibromobutane a. p ; r; q ; D - s b. q ; s ; p ; D r c. p ; r; s ; D q d. q ; r, s ; D p (chlorobenzene) q(benzyne mechanism); (cis--butene)-s ((±)-, -dibromobutane); (trans--butene)-p(meso-, -dibromobutane); D(p-nitrochlorobenzene)-r-(bimolecular /mechanism). rsn 7. (1 mol) NS / Fe H () () (i) Mg/ether (ii) (iii) H + () The structure of (c) is a. b. c. d. H H H Dr. Sangeeta Khanna Ph.D EMISTRY ING IRLE

4 Mg NS Mg H (i) (ii) HH 8. To prepare -Methylbutane from ethyl chloride which of following will be the best reagent? a. Na (dryether) b. c. Li + ux d. Li ux Na (dryether) H u LI ux Li + -Methylbutane SETIN (ssertion and Reason) Negative Marking [-1] This Section contains 10 multiple choice questions. Each question has four choices ), ), ) and D) out of which NLY NE is correct. Marks: 10 4 = 40 (a) Statement -1 is True, Statement- is True; Statement- is a correct explanation for Statement-1 (b) Statement- 1 is True, Statement- is True; Statement- is NT a correct explanation for Statement-1 (c) Statement-1 is True, Statement - is False (d) Statement 1 is False, Statement- is True 1. Statement 1: Nucleophilicity does not always match with basicity. Statement : While nucleophilcity is more related to size, polarizability and steric factors, the basicity is the ability to abstract a proton from a substrate & depend on stability of bond with hydrogen. Statement- 1: Low reactivity of the haloarenes compared to alkylhalides has been attributed to delocalization of electrons by resonance and the halogens are linked to sp hybridized carbons in haloarene. Statement : The presence of electron withdrawing group like F at ortho position to the halogen atom makes the aryl halides more susceptible to nuclephilic attack.. Statement 1: when treated with NaN gives mainly the corresponding cyanide or nitrile. Statement : Sodium cyanide have only one nucleophilic centre on carbon atom. Dr. Sangeeta Khanna Ph.D 4 EMISTRY ING IRLE

5 N is ambident Nucleophile. 4. Statement 1: Fluorobenzene undergoes nucleophilic substitution much faster than chlorobenzene. Statement : Fluorine being more electronegative causes more decrease in electron density at the carbon leading to a faster attack by the nucleophile & it also stablise intermediate formed after nucleophilic attack. 5. Statement 1: 7 H 7 [7-omocyclohepta-1,,5-triene] readily give yellow ppt. with gn. Statement : fter loss of ion, it becomes aromatic It is 6. Statement 1: bnormal R.T.R [Reimer Tiemann s reaction] of pyrrole shows ring expansion Statement : ttacking reagent in R.T.R is dichlorocarbene 7. Statement 1: Ph N H on heating in presence of g give vinylbenzene as major product Statement : Least acidic -hydrogen will be attacked by H. It is Hoffmann s elimination reaction 8. Statement 1: liphatic pri-amine are less reactive than aromatic pri.amine on reaction with & alc. KH Statement : oth give foul smelling isocyanide on reacting with & alc. KH D liphatic Primary amine are more reactive due to e donating effect of alkyl gp, attack of carbene will be fast 9. Statement 1: rder of acidic strength of trihalomethane is: > F > > I Statement : onjugate base of is resonance stabilized and for rest of the trihalide, decrease in [ I] effect will decrease the acidic strength. 10. Statement 1: In Reimer Tiemann reaction of phenol only one aldehyde group will be introduced at either ortho & para position Statement : ldehyde group introduced after first RTR, will deactivate the ring for further Reimer Tiemann s reaction Dr. Sangeeta Khanna Ph.D 5 EMISTRY ING IRLE

6 SETIN (Paragraph Type) Negative Marking This Section contains paragraphs. Each of these questions has four choices ), ), ) and D) out of which NLY NE is correct. (Mark only one) 8 4 = Marks Passage 1 Ether, R X Mg RMg X Grignard reagents may be prepared from 1, and halides as well as from vinyl and aryl halide. Vicinal dihalide and those halide which contain acidic tail do not form grignard reagent. 1. Which of the following halides is most reactive for the preparation of grignard reagent? F I a. b. c. d. D I arbon Iodine bond is weaker. Which of the following compounds can form grignard reagent on reaction with Mg/Ether? a. b. c. d. Mg Ether PhMg. Mg/THF NS alc. KH Identify structure of product (): Mg Mg a. b. c. d. Mg Mg Mg NS alc. Ether KH Passage - Type of elimination reaction in which least substituted alkene is major product known as Hofmann s elimination. Such reaction occur in following condition: (X) when base is bulky (Y) when leaving group is very poor such as fluoride, ammonium group ( NR ) etc. (Z) when alkyl halide contain one or more double bonds. Dr. Sangeeta Khanna Ph.D 6 EMISTRY ING IRLE

7 4. What is the major product of the following reaction? H H Me ΘK a. H H b. H c. H H d. None of these 5. Which of the following will not produce Hofmann s alkene as major product on elimination a. b. H N c. d. D F + H S 6. H 5 a. = b. = c. d. H 5 Passage ryl halides do not undergo nucleophilic substitution under ordinary conditions. This is due to stronger bond in aryl halides which acquires partial double bond character because of resonance. Reactivity becomes more when electron withdrawing groups are present in the ring. ryl halides also undergo electrophilic substitution at ortho and para positions because these are the position of the high electron density due to +R effect of halogen. H 5 7. Major product N a. b. c. d. N N N Dr. Sangeeta Khanna Ph.D 7 EMISTRY ING IRLE

8 8. In its nucleophilic substitution reactions, aryl halide resembles a. Vinyl chloride b. llyl chloride c. enzyl chloride d. Ethyl chloride SETIN D (More than ne nswer) No Negative Marking This Section contains 6 multiple choice questions. Each question has four choices ), ), ) and D) out of which more than one may be correct. 6 5 = 0 Marks 1. Which of the following combination give H H? 6 5 a. PhMg and H b. Mg and Ph c. Mg and 6H5 H5 d. Mg and Ph,,D. Which of the following are correct order of nucleophilicity?. a. NH NH NH b. Θ Θ Θ Θ c. F I d.,,d H H H H H H H H H 5 (I) H H H 5 (II) H H H 5 (III) Which of the following statements are true about these isomers? Θ Θ Θ H H > H H H H H H 5 (IV) a. I and II is a pair of enantiomers b. III and IV is a pair of enantiomers c. II is the diastereomer of III and IV d. I and III are homomers,, 4. ompound () formula H 9 N, on reaction with & alc. KH gives foul smelling compound (). Which of the following is correct structure of & respectively a. NH & N b. NH & N c. NH & N d. N & N, 5. n alcohol () of molecular formula 5 H 1, gives turbidity with anhyd. Zn & onc. H within five minutes. n reaction with NaI, it gives yellow ppt. of I. What will be the IUP name of alcohol. a. -pentanol b. -methylbutan-1-ol c. -methylbutan--ol d., -Dimethylpropan-1-ol, Dr. Sangeeta Khanna Ph.D 8 EMISTRY ING IRLE

9 6. Which of the following compound will give iodoform test a. H b. I c. d.,, H NH SETIN E (Matrix Type) No Negative Marking This Section contains questions. Each question has four choices (,, and D) given in olumn I and five statements (p, q, r, and s) in olumn II. 8 = 16 Marks 1. Match List I with List II (Single Match) olumn I (Statement) olumn II (Reason) () H S is weaker nucleophile than S Θ (p) ulky group present on nucleophilic centre H decreases nucleophilicity () Θ Θ (q) Nucleophilicity decreases on going from left is stronger nucleophile than N H to right in the period of periodic table () (r) species with negative charge is a stronger R P is stronger nucleophile than R N nucleophile than a similar species without a (D) Θ H is weaker nucleophile than Θ r; q; s; D p. Match olumn I with olumn II. (More than ne Match) olumn I I H (s) negative charge Nucleophilicity increases on going down in the group of the periodic table olumn II () (p) Intermediate carbocation () () N N Θ F H (q) (r) nd order 1 st order (D) (s) Unimolecular Na + p, r, s; s, q; p, r, s; D q = SN 1 attack at Iodine; = E 1(b)_ Mechanism = E 1 elimination (no hydrogen] D= With ulky ase, E elimination give Hoffmann s product Dr. Sangeeta Khanna Ph.D 9 EMISTRY ING IRLE

10 SETIN F (Integer Type) No Negative Marking This Section contains 7 questions. The answer to each question is a single digit integer ranging from 0 to 9. The correct digit below the question number in the RS is to be bubbled. 7 5 = 5 Marks 1. Total number of hyperconjugating structures possible in the alkene formed as a major product in the reaction Possible lkenes is Hoffmann s alkene = () Hyperconugative structure Hoffmann elimination reaction hence least stable alkene is formed as major product.. The maximum number of isomers (including stereoisomers) that are possible on monochlorination of the following compound is: 8 ompound is (1) () N H one chiral stereoisomers (i) I (ii) gh, H Monochloro products are () (4) H Two chiralboth dif f erent 4 stereoisomers. Total number of structural isomers of compound 5 H 11 which can show E elimination. 7 E elimination means alkene without rearrangement E (i) E (ii) E (iii) Dr. Sangeeta Khanna Ph.D 10 EMISTRY ING IRLE

11 E E (iv) (v) E E (vi) (vii) (viii) E (alkene without rearrangement is not possible) 4. The total number of methyl groups in the major product of reaction Na Dry ether Tertiary alkyl halide gives alkene in Wurtz reaction. Na Dry ether 5. Total number of alkenes structure which will show geometrical isomerism of molecular formula 6 H 1. 4 (i) = (ii) (iii) (iv) = [1-hexene;,-dimethylbut--ene;,-dimethylbut-1-ene;,-dimethylbut-1-ene do not show geometrical isomer] 6. How many molecule of Mg will be required for the given molecule H H R 5 [two for ester, one for ketone and two for acidic hydrogen] gm of a compound of molecular formula H 8, on reaction with excess of Mg give.4 lit 4 at STP. How many acidic Hydrogen are present in this compound 1 H 8 4 If 7.6 gm compound give =.4 lit M.Wt. 76 gm? 76[M.Wt.) will give =.4 lit 7.6 gm.4 lit. i.e. 1 mol Dr. Sangeeta Khanna Ph.D 11 EMISTRY ING IRLE