Grignard's Reagent Exercise - Allen PDF

Grignard's Reagent EXERCISE - O SINGLE CORRECT TYPE QUESTIONS Preparation of Grignard reagent & Acid Base Reaction 1. Grignard reagent can be prepared by dry...

Grignard's Reagent EXERCISE - O SINGLE CORRECT TYPE QUESTIONS Preparation of Grignard reagent & Acid Base Reaction 1. Grignard reagent can be prepared by dry dry (A) CH3—CH2—Cl + Mg ⎯⎯⎯→ ether (B) CH3— CH— CH2 + Mg ⎯⎯⎯→ ether Cl OH CH3 (C) CH3 C OH +Mg ⎯⎯→ (D) All of them CH3 CGR060 dry ether D3O 2. X + Mg Y CH3CHCH3 D Identify X and Y – Br (A) Br,Mg Br (B) , MgBr (C) Br, MgBr (D) Br, Mg CGR061 3. The correct order of reactivity of halides with Mg for the formation of Grignard reagents :- (A) RI > RCl > RBr (B) RBr > RCl > RI (C) RI > RBr > RCl (D) RCl > RBr > RI CGR062 4. Propane is not formed when C3H7MgBr is treated with :- (A) H2 (B) Phenol (C) Ethanoic acid (D) 1–Butyne CGR063 5. MgBr + CH3OH (X) , product (X) is: (A)Propane (B) Ethane (C) Butane (D) Propan–2–ol CGR064 Br Mg (P) 6. Br ether (P) is :- (A) MgBr (B) Br BrMg BrMg (C) H2C==CH2 (D) All CGR065 www.allen.in [ 277 ]  JEE (Main + Advanced) : Chemistry 7. C2H5MgBr + CH3—NH2 ⎯→ (P) Product (P) is :- (A) C2H6 (B) C3H8 (C) C2H5NH2 (D) No reaction CGR066 8. Which gas is released during the following reaction :- HCCH + MeMgBr ⎯→ (A) Ethane (B) Propane (C) Methane (D) Butane CGR067 9. Which of the following will undergo acid-base reaction with Grignard reagent :- (A) HCCH (B) R–OH (C) R–CO2H (D) All of these CGR068 10. Find the major product for the given following reaction : Br CH3—MgCl + (P) CH2–Cl CH3 CH3 Br Br Br (A) (B) (C) (D) H3C CH2–Cl CH2–CH3 CH2–Cl CH2–Cl CGR069 Chemical Reaction of Grignard Reagents (NAER, NAR, SN Reaction) 11. For the reaction the product expected is : O (1) MeMgBr(2mole) O (P) (2) H3O O Me OH O (A) O (B) O Me OH Me OH O OH C—CH3 (C) O (D) CH3 C—OH Me Me O CGR070 [ 278 ] www.allen.in Grignard's Reagent Br Mg (i) 14CO2 NaHCO3 12. (A) (ii) H/H2O (B) (C) gas Product C is (A) CO (B) 14CO2 (C) CO2 (D) A mixture of 14CO2 and CO2 CGR073 Miscellaneous Mg (1mole) 13. Br–CH2CC–CH2–Br Et2O Product. The major product is ? (A) Br–Mg–CH2–CC–CH2–Br (B) Cyclobutyne (C) —CH2–CC–CH2—n (D) CH2=C=C=CH2 CGR071 14. Find product C of the following reaction : Cl2 Mg CH3CHO PhCH3 h (A) ether (B) NH4Cl (C) OH CH2–CH–CH3 CH3 CH3 CH–CH3 (A) (B) CH3 CH3 OH CH–CH3 (C) (D) CH3 CH HO CH3 CGR078 MULTIPLE CORRECT TYPE QUESTIONS Miscellaneous 15. From which compound Alcohol is formed when RMgX in presence of H3Ois treated with : (A) Ethanoyl chloride (B) O2 (C) oxirane (D) trimethyl orthoformate CGR079 16. In which of the following reactions 3 alcohol will be obtained as a product. (A) —MgBr(excess) + H–CO–Cl H (B) PhMgBr(excess) + CH3–CO–Cl H (C) CH3MgBr(excess) + CH3–CO–O–CO–CH3 H (D) CH3MgBr(excess) + Cl–CO–OEt H CGR080 www.allen.in [ 279 ]  JEE (Main + Advanced) : Chemistry 17. Select the correct statement : (A) 1,4–dibromo butane react with excess of magnesium in ether to generate di–Grignard reagent. (B) 1,2–dichlorocyclohexane treated with excess of Mg in ether produces cyclohexene. (C) Vicinal dihalides undergo dehalogenation to give alkene when heated with Zn dust or Mg. (D) 1,3–dichloropropane by treatment with Zn dust or Mg forms cyclopropane. CGR081 18. Nucleophilic addition of Grignard reagent can not occur in OO O O (A) CH3–C–C–CH3 (B) CH3–C–CH2–C–CH3 O O (C) CH3–C–CH2–CH2–C–CH3 (D) O O CGR082 19. O (i) CH3MgBr (X) (ii) H/H2O Correct statement about X is (A) The product is optically active. (B) The product contains plane of symmetry. (C) The product shown geometrical isomerism. (D) The product shown optical isomerism. CGR083 [ 280 ] www.allen.in Grignard's Reagent EXERCISE - S Preparation of Grignard reagent & Acid Base Reaction 1. How many total possible Grignard reagent can give 3–methylpentane on treatment with H ? CGR084 (2) O OH C (3) OH RMgX (2moles) 2. (1) H S CCH (4) The sum of the positions from where deprotonation will occur is CGR076 Miscellaneous O  ether 3. Me S—Cl + OH (P) + MgBr (Q)  Me major O No. of chiral centre in product (Q). CGR074 4. Compounds are shown with the no. of RMgX required for complete reaction as (x), (y) and (z). what is x+y+z ? (i) CH3COOC2H5 (x) (ii) CH3COCl (y) (iii) HOCH2COOC2H5 (z) CGR075 5. Number of moles of RMgX required for complete reaction with one mole of the following compound is ? COCl HO O CGR077 6. Choose the final product (B) of the following reaction. Et2O H–Br, h CH2–CH–CH2–Br + Mg , H3O [A] H3C-O-O-CH3 [B] O CGR085 conc. 1. O O3 Br2/h Mg, H2SO4 7. [A] [B] Et2O [C]  [D]  [E] Zn/H2O O 2. H3O Select the correct structure of 'A'. CGR086 CH3 Mg/Ether (i) CO2 SOCl2 (i) (C6H5CH2)2CuLi 8. H3C— —Br [P] [Q] [R] [S] (ii) H2O/H CH3 CGR087 www.allen.in [ 281 ]  JEE (Main + Advanced) : Chemistry O O PhMgBr CH3MgBr H/H2O 9. [P] [Q] Product (1eq.) (1eq.) (1eq.) O The product formed in the reaction is CGR088 10. Calculate the number of molecules of Grignard reagent consumed by 1 molecule of following compound. H O O O O HO NO2 CGR089 11. Find the number of CH3MgBr molecules used the given reactant, to react completely. O O CH3MgBr (excess) O O (ether) HO NHCH3 O CGR090 [ 282 ] www.allen.in Grignard's Reagent EXERCISE - JEE (Main) PYQ 1. Which of the following compounds reacts with ethylmagnesium bromide and also decolourizes bromine water solution :- [JEE (Main) 2019] CN O CN OCH3 OH CH2–CO2CH3 CH (1) (2) (3) CH2 (4) CGR091 2. The aldehydes which will not form Grignard product with one equivalent Grignard reagents are : [JEE (Main) 2019] CHO CHO (A) (B) HO2C CHO CHO (C) (D) H3CO HOH2C (1) (B), (C), (D) (2) (B), (D) (3) (B), (C) (4) (C), (D) CGR033 OH 3. CH3–CH2–C–CH3 cannot be prepared by : [JEE (Main) 2019] Ph (1) HCHO + PhCH(CH3)CH2MgX (2) PhCOCH2CH3 + CH3MgX (3) PhCOCH3 + CH3CH2MgX (4) CH3CH2COCH3 + PhMgX CGR034 4. The major product (Y) in the following reactions is : [JEE (Main) 2020] CH3 HgSO4,H2SO4 CH3–CH–CCH (X) (i) C2H5MgBr, H2O (Y) H2O (ii) Conc. H2SO4/ CH2 CH3 (1) H3C–C–CH–CH3 (2) CH3 – CH – C = CH – CH3 C2H5 CH3 CH3 CH3 (3) CH3 – C = C – CH3 (4) CH3 – CH – C = CH2 CH2 CH3 CH2 CH3 CGR092 5. The number of chiral centres present in [B] is _______. [JEE (Main) 2020] (i) C2H5MgBr —CH–CN (ii) H3O+ [A] (i) CH3MgBr [B] (ii) H2O CH3 CGR093 www.allen.in [ 283 ]  JEE (Main + Advanced) : Chemistry 6. The product formed in the first step of the reaction of [JEE (Main) 2021] Br CH3–CH2–CH–CH2–CH–CH3 Br with excess Mg/Et2O(Et=C2H5) is: (1) CH3–CH2–CH–CH2–CH–CH3 (2) CH3–CH2–CH–CH2–CH–CH3 CH3–CH–CH2–CH–CH2–CH3 CH3–CH2–CH–CH2–CH–CH3 MgBr CH2 (3) CH3–CH (4) CH3–CH2–CH–CH2–CH–CH3 CH–CH3 MgBr CGR035 CN (i) C6H5MgBr (1.0 equivalent), dry ether 7. (ii) H3O (X) [JEE (Main) 2021] Major Product OCH3 The structure of X is : NH2 NH2 (1) (2) C6H5 OCH3 O O C6H5 C6H5 (3) C6H5 (4) OCH3 CGR036 8. To synthesise 1.0 mole of 2-methylpropan-2-ol from Ethylethanoate ________ equivalents of CH3MgBr reagent will be required. [JEE (Main) 2021] CGR037 9. Which of the following compounds will provide a tertiary alcohol on reaction with excess of CH3MgBr followed by hydrolysis? [JEE (Main) 2021] O CH3 OCH2CH3 (1) (2) O NC C CH O O (3) CH3 (4) OH O CGR094 [ 284 ] www.allen.in Grignard's Reagent O (i) C2H5MgBr, dry ether 10. (ii) H2O, HCl P (Major product) Consider the above reaction, the major product 'P' is: [JEE (Main) 2021] OH OH (1) (2) OH OH (3) (4) Cl Cl CGR095 11. The correct sequential addition of reagents in the preparation of 3-nitrobenzoic acid from benzene is: [JEE (Main) 2021] (1) Br2/AlBr3, HNO3/H2SO4, Mg/ ether, CO2, H3O+ (2) Br2/AlBr3, NaCN, H3O+, HNO3/H2SO4 (3) Br2/AlBr3, HNO3/H2SO4, NaCN, H3O+ (4) HNO3/H2SO4, Br2/ AlBr3, Mg/ether, CO2, H3O+ CGR096 12. Given below are two statements : [JEE (Main) 2021] Statement I : Ethyl pent–4–yn–oate on reaction with CH3MgBr gives a 3°–alcohol. Statement II : In this reaction one mole of ethyl pent–4–yn–oate utilizes two moles of CH3MgBr. In the light of the above statements, choose the most appropriate answer from the options given below : (1) Both Statement I and Statement II are false. (2) Statement I is false but Statement II is true. (3) Statement I is true but Statement II is false. (4) Both Statement I and Statement II are true. CGR039 13. Which one of the following is the major product of the given reaction? [JEE (Main) 2021] CH3 NC O (i) 2CH3MgBr Major product (ii) H3O+ CH3 (iii) H2SO4, heat O CH3 CH3 CH3 NC CH3 (1) (2) CH3 CH3 CH3 O CH3 NC CH3 CH3 H3C (3) (4) CH3 CH3 CGR097 www.allen.in [ 285 ]  JEE (Main + Advanced) : Chemistry 14. In the following sequence of reactions the P is : [JEE (Main) 2021] Cl +Mg ⎯⎯⎯dry ether →[A] ⎯⎯⎯→ ethanol P (Major Product) O–CH2CH3 CH2CH3 (1) (2) (3) (4) CGR038 15. For the following : [JEE (Main) 2021] 1. Br2/Fe/ 2. Mg/dry ether 3. CH3OH Products OCH3 H OCH3 (1) + HMgBr (2) + Mg Br CH3 OH Br H (3) + Mg (4) + Mg Br OCH3 CGR098 16. In the given reaction [JEE (Main) 2021] OH (i) 2Mg, THF —C— 2A (ii) Methyl benzoate (iii) H2O/H+ ‘A’ can be (1) benzyl bromide (2) bromobenzene (3) cyclohexyl bromide (4) methyl bromide CGR099 MgBr O O H2O 17. + CH3–C–CH2–C–CH3 'A' 'B' Consider the above reaction sequence Major Product MgBr and identify the product B. [JEE (Main) 2022] OH OH (1) CH3 (2) HO CH3 OH OH H3C O O (3) (4) H3C OH H3C CH3 CGR100 [ 286 ] www.allen.in Grignard's Reagent 18. What will be the major product of following sequence of reactions? [JEE (Main) 2022] (i) n − BuLi, n − C5H11Cl n − Bu −  (ii) Lindlar cat , H2 n-Bu n-Bu (1) (2) H11C5 n-Bu n-Bu C5H11 C5H11 (3) H11C5 n-Bu (4) n-Bu CGR101 Br COOH (CH3)3CLi (i) CO2 19. (A) (ii) H3O+ OH OH In the given conversion the compound A is: [JEE (Main) 2022] Li Li (1) (2) OH OLi Br C(CH3)3 (3) (4) OC(CH3)3 OH CGR102 20. A sample of 4.5 mg of an unknown monohydric alcohol, R–OH was added to methylmagnesium iodide. A gas is evolved and is collected and its volume measured to be 3.1 mL. The molecular weight of the unknown alcohol is ____ g/mol. [Nearest integer] [JEE (Main) 2022] CGR103 21. Which reactant will give the following alcohol on reaction with one mole of phenyl magnesium bromide (PhMgBr) followed by acidic hydrolysis ? [JEE (Main) 2022] Ph | Ph—C—OH | CH3 (1) CH3–CN (2) Ph–CN O O (3) CH3–C–O–Ph (4) Ph–C–CH3 CGR104 22. A 100 mL solution of CH3CH2MgBr on treatment with methanol produces 2.24 mL of a gas at STP. The weight of gas produced is _______ mg. [nearest integer] [JEE (Main) 2022] CGR105 www.allen.in [ 287 ]  JEE (Main + Advanced) : Chemistry 23. Compound 'A' undergoes following sequence of reactions to give compound 'B'. The correct structure and chirality of compound 'B' is: [JEE (Main) 2022] [where Et is –C2H5] (i) Mg,Et2O (ii) D2O B Br Compound 'A' (1) , Achiral (2) , Chiral D OD , Chiral (3) D (4) OD , Achiral CGR106 24. Find out the major product from the following reaction [JEE (Main) 2023] O 1) MeMgBr/Cul 2) nPrI O O (1) Me (2) Me Me Me Me HO Me (3) Me (4) Me CGR107 O OH OH x mol of MeMgBr OH 25. H H3O+ Me H (y mole) The ratio x/y on completion of the above reaction is _________. [JEE (Main) 2023] CGR108 (i) NaI, H3PO4 26. H3C—CH2—CH—CH3 [X] (ii) Mg, Dry ether Product OH (iii) D2O Product [X] formed in the above reaction is : [JEE (Main) 2023] H (1) H3C–CH2–CH–CH3 (2) H3C–CH2–C–CH3 D OH (3) H3C–CH2–CH=CH2 (4) H3C–CH=CH–CH3 CGR109 [ 288 ] www.allen.in Grignard's Reagent O (i) Mg 27. ‘A’ (Major Product) A is [JEE (Main) 2023] Br (ii) H2O OH O (1) (2) MgBr OH O (3) MgBr (4) Br OH OH CGR110 28. The major product for the following reaction is: [JEE (Main) 2023] SH HO CN S O (1) HO CN (2) HS CN (3) C=NH (4) C=NH OH S S O CGR111 www.allen.in [ 289 ]  JEE (Main + Advanced) : Chemistry EXERCISE - JEE (Advanced) PYQ 1. (CH3)3CMgCl reaction with D2O produces: [IIT 1997] (A) (CH3)3CD (B) (CH3)3OD (C) (CD3)3CD (D) (CH3)3OD CGR058 2. CH3MgBr + Ethyl ester → which can be formed as product? (excess) [IIT 2003] CH2CH3 CH3 (A) HO CH2CH3 (B) HO CH2CH2CH3 CH2CH3 CH2CH3 CH2CH3 CH3 (C) HO CH2CH3 (D) HO CH3 CH3 CH3 CGR059 3. Choose the correct option(s) for the following set of reactions [JEE (Advanced) 2019] (i) MeMgBr Conc. HCl C6H10O Q S (ii) H2O (major) 20% H3PO4, 360 K (i) H2, Ni HBr, benzoyl peroxide T (ii) Br2, h R U  (major) (major) (major) H3C CH3 H3C CH3 Br Cl Cl Br (A) (B) U S S U CH3 H3C Br CH3 H3C Br Cl Br (C) (D) S T U T CGR112 [ 290 ] www.allen.in Grignard's Reagent JEE (Main) Practice Paper This paper is for yourself practice and assessment the discussion of this paper is optional though you can see PDF solutions or video solutions or solutions in hardcopy whichever is provided. SECTION–A This section contains TWENTY questions. Each question has FOUR options (1), (2), (3) and (4). ONLY ONE of these four options is correct. For each question, darken the bubble corresponding to the correct option in the ORS. For each question, marks will be awarded in one of the following categories : Full Marks : +4, if only the bubble corresponding to the correct option is darkened. Zero Marks : 0, if none of the bubbles is darkened. Negative Marks : –1 in all other cases 1. Compound P and R in the following reaction are (i) CH3MgBr H2SO4 Hydroboration CH3CHO (P) (Q) (R) (ii) H2O  oxidation (1) identical (2) positional isomer (3) functional isomers (4) optical isomers CGR001 2. Consider the following reaction sequence, O 1. CH3Mgl POCl3 (P) (Q) 2. H2O Pyridine, 0C The product (Q) is- CH3 CH3 (1) Cl (2) OPOCl2 CH2 CH3 (3) (4) CGR002 3. The final product (IV) in the sequence of reactions is : CH2―CH2 PBr3 Mg O H2O CH3CHOH I Ether II III IV CH3 (1) CH3—CHOCH2CH2OH (2) CH3—CHCH2CH2Br CH3 CH3 (3) CH3—CH—CH2CH2OH (4) CH3—CHOCH2CH3 CH3 CH3 CGR003 www.allen.in [ 291 ]  JEE (Main + Advanced) : Chemistry 4. In the reaction dry ether (P) H3O (Q) Cl CH2Br + CH3CHO + Mg the product (Q) is: (1) CH3CH CH2Br (2) Cl CH2CHCH3 OH OH (3) Cl CH2CH2CH2OH (4) CH2==CH CH2Br OH CGR004 5. Find the major product for the given following reaction : CH3—MgCl + SnCl4 (P) (1) Sn(CH3) (2) Sn(CH3)2 (3) Sn(CH3)3 (4) Sn(CH3)4 CGR005 6. Find the major product for the given following reaction : Cl CH3MgCl + (P) CH3 Br Cl (1) (2) (3) (4) No reaction H3C CH3 CGR006 7. CH3—MgX + CH2—CH2 (P) (excess) Cl OMe Find product (P) (1) CH2—CH2 (2) CH2—CH2 (3) CH2—CH2 (4) None of these CH3 OMe CH3 CH3 Cl CH3 CGR007 8. Consider the following sequence of reactions. H (i) C2H5MgBr H2SO4, heat (i) O3 (P) (Q) (R) + (ii) H2O (ii) Zn, H2O O O The ketone (P) is : (1) (2) O O (3) (4) O O CGR008 [ 292 ] www.allen.in Grignard's Reagent 9. Reactivity of EtMgBr with the following in the decreasing order is: (i) HCHO (ii) MeCHO (iii) Me–CO–Me (iv) Cl3C–CHO (1) (i) > (ii) >(iii) > (iv) (2) (iv) > (iii) > (ii) > (i) (3) (iv) > (i) > (ii) > (iii) (4) (iii) > (ii) > (i)> (iv) CGR009 10. In the following reaction sequence aq.H2SO4 1. CH3Mgl Ph—C CH (P) (Q) the product (Q) is: Hg2 2. H2O (1) PhCOCH3 (2) PhCH2CHOHCH3 Ph CH3 (3) C (4) PhCH2COCH3 CH3 OH CGR010 11. Which of the following products is formed when benzaldehyde is treated with CH3MgBr and the addition product so obtained is subjected to acid hydrolysis (1) Secondary alcohol (2) A primary alcohol (3) Phenol (4) Tert-Butyl alcohol CGR011 12. Which carbonyl compound (s) can be used to produce 2-Phenylbutan-2-ol on reaction with a suitable Grignard reagent? (1) CH3–CO–CH2–CH3 (2) Ph–CO–CH3 (3) Ph–CO–CH2–CH3 (4) All of these CGR012 13. 6-Bromo-2-hexanone is treated with magnesium in presence of THF produce X as major product. What is X. H3C OH (1) Br–Mg–CH2–CH2–CH2–C–CH2–CH3 (2) O H3C OH OH (3) (4) CH3 CGR013 (i)CH3MgBr(excess) 14. Phenyl acetate ⎯⎯⎯⎯⎯⎯  → 'P', 'P' can be (ii)H Ph Me Ph Ar Ph Me H3C CH3 (1) (2) (3) (4) H OH Me OH Et OH H3C OH CGR014 15. An acid halide (X) reacts with excess of Grignard reagent (Y), the product can be Ph Me Me (1) Ph—C—Ph (2) Ph—C—Et (3) H—C—Et (4) Me—C—Et OH OH OH O CGR015 www.allen.in [ 293 ]  JEE (Main + Advanced) : Chemistry 16. Which of the following can not react with Grignard reagent: (1) (2) D2O (3) CH2=CH2 (4) Phenol CGR016 17. C4H10O + CH3MgBr ⎯→ No Reaction (Y) (Excess) Y is : (1) (2) (3) (4) OH OH O OH CGR017 18. The order of reactivity of phenyl magnesium bromide (PhMgBr) with the following compounds : CH3 CH3 Ph C=O , C=O and C=O H CH3 Ph I II III (1) III > II > I (2) II > I > III (3) I > III > II (4) I > II > III CGR018 19. Arrange the following compounds in decreasing order of nucleophilic addition reaction ? (P) CH3–CHO (Q) CH3–CO–CH3 (R) COCl2 (S) Ph–CHO (1) R>P>S>Q (2) P>Q>R>S (3) Q>R>S>P (4) R>S>P>Q CGR019 20. Which of the following can give a Grignard reagent when reacted with magnesium in dry ether? (1) C2H6 (2) C2H5Cl (3) C2H5OH (4) C2H5CN CGR020 SECTION-B  This section will have TEN questions. Candidate can choose to attempt any 5 questions out of these 10 questions. In case if candidate attempts more than 5 questions, first 5 attempted questions will be considered for marking.  The answer to each question is a NUMERICAL VALUE.  For each question, enter the correct numerical value (Answer should be rounded off to the nearest integer).  Answer to each question will be evaluated according to the following marking scheme: Full Marks : +4, if only correct answer is given. Zero Marks : 0, if no answer is given. Negative Marks :-1 for incorrect answer 1. How many carbonyl compounds will give secondary alcohol with molecular formula C5H12O after reaction with CH3MgBr followed by hydrolysis. CGR021 2. CH3–C—C–CH3 ⎯⎯⎯ PhMgBr → ⎯⎯→ No. of product (X) ⎯⎯⎯⎯⎯⎯→ No. of fractions (Y) H2O Fractional distillation (excess) O O Report your answer as XY. CGR022 [ 294 ] www.allen.in Grignard's Reagent 3. How many butyl bromide can be converted into Grignard reagent followed by their reaction with acid to form n-Butane. CGR023 SH SH OC2H5 (1) (X) CH3MgBr 4. HO (2) H/H2O HO O HO Determine the value of X CGR024 5. How many alkyl chlorides would yield 3-methylpentane on conversion into the Grignard reagent followed by treatment with absolute ethanol? CGR025 HgSO4/ 6. C CH (P) 2mol of Me  MgBr (Q) H2SO4 H3O Number of 3 Alcohol formed in product Q CGR026 7. How many carbonyl isomers of C5H10O reacts with PhMgBr to give racemic mixture (excluding steroisomer). CGR027 Br (i) Mg/THF 8. (P) H–Br (Q) No. of sp3 hybridized carbon in (Q) is :– CGR028 9. How many moles of methane is formed when one mole of lactic acid reacts with excess methyl magnesium chloride ? CGR029 10. The number of moles of Grignard reagent consumed per mole of the compound is CH2(OH)–CH2–CO–CH2–CH2–COEt CGR030 www.allen.in [ 295 ]  JEE (Main + Advanced) : Chemistry JEE (Advanced) Practice Paper This paper is for yourself practice and assessment the discussion of this paper is optional though you can see PDF solutions or video solutions or solutions in hardcopy whichever is provided. SECTION–I This section contains FOUR questions. Each question has FOUR options (A), (B), (C) and (D). ONLY ONE of these four options is correct. For each question, darken the bubble corresponding to the correct option in the ORS. For each question, marks will be awarded in one of the following categories: Full Marks : +3, if only the bubble corresponding to the correct option is darkened. Zero Marks : 0, if none of the bubbles is darkened. Negative Marks : –1, in all other cases 1. Which of the following is incorrect regarding the given reaction? O CH2CH2CH2Cl ⎯⎯⎯⎯ CH3MgI → CH3 (A) Nucleophilic substitution (B) Intramolecular nucleophilic attack (C) Dehydration (D) Nucleophilic addition CGR040 O H/H2O Mg 2. + CH3MgBr (P) HBr (Q) (R) HCHO (S), S is Ether H/H2O OH OH (A) (B) (C) OH (D) OH CGR041 3. Arrange these compounds in decreasing order of reactivity for the nucleophilic attack : (I) Acid chloride (II) Aldehyde (III) Ketone (IV) Ester Select the correct answer from the codes given below: (A) I > II > III > IV (B) IV > III > II > I (C) III > II > I > IV (D) I > IV > II > III CGR042 [ 296 ] www.allen.in Grignard's Reagent CH3 PBr3 Mg/Et2O (Y) (i) CH3–CH–CHO (Z) 4. OH (X) (ii) H3O (I) Y is Br (II) Y is MgBr OH CH3 H CH3 (III) Z is —C—C—CH3 (IV) Z is —C—C—CH3 H H H OH Select the correct code for given reaction. (A) I and III (B) II and IV (C) I and IV (D) II and III CGR043 SECTION-II This section contains SIX questions. Each question has FOUR options for correct answer(s). ONE OR MORE THAN ONE of these four option(s) is (are) correct option(s). For each question, choose the correct option(s) to answer the question. Answer to each question will be evaluated according to the following marking scheme: Full Marks : +4, if only (all) the correct option(s) is (are) chosen. Partial Marks : +3, if all the four options are correct but ONLY three options are chosen. Partial Marks : +2, if three or more options are correct but ONLY two options are chosen, both of which are correct options. Partial Marks : +1, if two or more options are correct but ONLY one option is chosen and it is a correct option. Zero Marks : 0, if none of the options is chosen (i.e. the question is unanswered). Negative Marks : –2, in all other cases. 5. Select the reaction in which one organometallic compound produces another organometallic compound. (A) CH3MgBr + HCC–Ph ⎯⎯ ⎯ Ether → (B) + CH3MgBr ⎯⎯ ⎯ Ether → H H OH SH (C) + ⎯⎯ ⎯ Ether → (D) CH3CH2Na + ⎯⎯ ⎯ Ether → MgI CGR044 O H3C CH3 H3C H3C CH3 CH3MgBr 6. O Cl Correct statement(s) is/are (A) Nucleophilic addition (B) Nucleophilic substitution reaction (C) Carbanion is intermediate (D) Product obtained is chiral CGR045 www.allen.in [ 297 ]  JEE (Main + Advanced) : Chemistry 7. Select the correct statement about Grignard reagent. (A) In Grignard reagent 3 and 4 membered cyclic ethers can not be used as a solvent. (B) In case of Grignard reagent any alkyl, aryl, vinyl, allyl group can not be taken as organic part. (C) Grignard reagent can not be prepared from alkyl or aryl fluorides. (D) The role of ether is to solvolyse RMgX and also provide medium for reaction. CGR046 8. Which of the following compound gives methane on treatment with CH3MgI? (A) (B) SH (C) (D) CGR047 9. Phenyl magnesium bromide reacts with phenyl acetylene, which of the following is/are expected as the product. (A) Benzene (B) Hydrocarbon (C) Grignard reagent (D) Alkyne CGR048 10. Compound CH3–CH2–CH–CH3 can be prepared by Ph–CH–OH (i) PhMgBr (A) CH3–CH2–CH–CHO (ii) H3O CH3 (i) PhCH2CHO (B) CH3–CH–CH3 (ii) H3O MgBr CH3 (i) CH3CH2–CH–MgBr (C) Ph–COCH3 (ii) H3O CH3 (D) PhCHO (i) CH3–CH  2–CH–MgBr (ii) H3O CGR049 SECTION–III This section contains TWO questions. Each question has matching lists. The codes for the lists have choices (A), (B), (C) and (D) out of which ONLY ONE is correct For each question, marks will be awarded in one of the following categories : Full Marks : +3, if only the bubble corresponding to the correct option is darkened. Zero Marks : 0, if none of the bubbles is darkened. Negative Marks : –1, in all other cases. [ 298 ] www.allen.in Grignard's Reagent 11. Match the column–I and column–II Column–II Column–I (Reaction) (No. of moles of CH3MgCl reacted) HO (A) (i) CH3MgCl (p) 4 (ii) H3O HO O O HO OH O HO CH3 (i) CH3MgCl (ii) H3O (B) (q) 3 COCH3 HO–C–CH3 CH3 O O HO OH (i) CH3MgCl (C) EtO–C–C–OEt (ii) H3O H3C–C–C–CH3 (r) 2 H3C CH3 O O HO OH (i) CH3MgCl (D) CH3–C–C–Cl (ii) H3O H3C–C–C–CH3 (s) 5 H3C CH3 (t) 1 (A) A-q, B–r, C–p, D–q (B) A-t, B–r, C–p, D–s (C) A-s, B–t, C–p, D–q (D) A-q, B–r, C–t, D–s CGR050 12. Match the List–I and List–II List–I List–II (A) C2H5Cl (1) Williamson synthesis (B) R–X+Mg+dry ether (2) Wurtz reaction (C) C2H5Cl+C2H5ONa (3) Anaesthetic (D) RX+Na+dry ether (4) Antiseptic (5) Grignard reagent The correct match is A B C D A B C D (A) 4 5 1 2 (B) 5 3 1 2 (C) 3 4 1 2 (D) 3 5 1 4 CGR051 www.allen.in [ 299 ]  JEE (Main + Advanced) : Chemistry SECTION-IV This section contains TWO paragraphs. Based on each paragraph, there are FOUR questions. Each question has FOUR options (A), (B), (C) and (D) ONLY ONE of these four options is correct. For each question, darken the bubble corresponding to the correct option in the ORS. For each question, marks will be awarded in one of the following categories : Full Marks : +3, if only the bubble corresponding to the correct answer is darkened. Zero Marks : 0, in all other cases. Passage for Ques. 13-14 The relative comparison of equilibrium constants of addition of RMgBr on four carbonyl compounds has been shown by the graph below. E Keq F G H compounds 13. Which compound corresponds to H if the four given compounds are: (A) p-NO2C6H4CHO (B) C6H5CHO (C) p-MeOC6H4CHO (D) CH3CH2CHO CGR052 14. Which compound corresponds to G if the four given compounds are: (A) CH3CHO (B) C6H5COCH3 (C) C6H5CHO (D) C6H5COC6H5 CGR053 Passage for Ques. 15-16 Grignard reagents resemble carbanion hence they act as strong nucleophiles as well as strong bases. They give nucleophilic addition reactions with compounds containing hetero multiple bonds such as carbonyl compounds. The addition products on acidic hydrolysis give alcohols. They readily take part in acid–base reactions with compounds containing acidic hydrogens. ⊝  ⊝  H2O R Mg X + O R O Mg X R OH + Mg(OH)X 15. Which of the following compound will not give acid–base reaction with RMgX ? (A) CH3–CH2–CN (B) CH3–CO–CH2–CO–CH3 (C) CH3–NO2 (D) CH3OH CGR054 16. Which of the following compounds give racemic mixture on reaction with methyl magnesium bromide? (A) HCHO (B) CH3–CO–CH3 (C) Ph–CHO (D) CH3–COCl CGR055 [ 300 ] www.allen.in Grignard's Reagent SECTION-V This section contains TWO questions. The answer to each question is a NUMERICAL VALUE. For each question, enter the correct numerical value (in decimal notation, truncated/rounded-off to the second decimal place; e.g. 6.25, 7.00, –0.33, –.30, 30.27, –127.30, if answer is 11.36777..... then both 11.36 and 11.37 will be correct). Answer to each question will be evaluated according to the following marking scheme: Full Marks : +3, if ONLY the correct numerical value is entered as answer. Zero Marks : 0, in all other cases. CH2CH2Cl CH3 H 17. Mg(1eq) (P) El2O H CH3 CH2CH2Cl Total no. of stereoisomer in product (P) CGR056 18. How many these reactions will give 1° alcohol as major product : H /H O (A) O ⎯⎯⎯⎯ 2 → O H /H O (B) → ⎯⎯⎯⎯→ + CH3MgBr ⎯⎯ 2 H /H O → ⎯⎯⎯⎯→ (C) HCHO + CH3MgBr ⎯⎯ 2 H /H O → ⎯⎯⎯⎯→ (D) CH3CHO + CH3MgBr ⎯⎯ 2 O O  (E) CH3–C–CH2–C–CH3+CH 3MgBr H /H2O (excess) → ⎯⎯⎯⎯ ⎯⎯ → O H /H O (F) → ⎯⎯⎯⎯→ + CH3MgBr ⎯⎯ 2 Cl (Excess) O H /H2O (G) → ⎯⎯⎯⎯→ + CH3MgBr ⎯⎯ (H) CH3CH2Br ⎯⎯⎯⎯ → NaOH(Aq.) H /H O → ⎯⎯⎯⎯→ (I) CH3MgBr + CO2 ⎯⎯ 2 CGR057 www.allen.in [ 301 ]  JEE (Main + Advanced) : Chemistry ANSWER KEY EXERCISE - O Que. 1 2 3 4 5 6 7 8 9 10 Ans. A C C A A C A C D B Que. 11 12 13 14 15 16 17 18 19 Ans. D C D A ABC BCD ABCD BD BC EXERCISE - S 1. (8) 2. (3) 3. (0) 4. (7) 5. (4) 6. HO–H2C–CH2–CH2–Br CH3 O 7. 8. H3C— —C–CH2–Ph CH3 OH 9. Me–C–COOH 10. (5) Ph 11. (6) EXERCISE - JEE (Main) PYQ Que. 1 2 3 4 5 6 7 8 9 10 Ans. 4 2 1 3 4 4 4 2 1 3 Que. 11 12 13 14 15 16 17 18 19 20 Ans. 4 3 1 1 2 2 1 3 2 33 Que. 21 22 23 24 25 26 27 28 Ans. 4 3 3 1 2 1 4 1 EXERCISE - JEE (Advanced) PYQ Que. 1 2 3 Ans. A D BD [ 302 ] www.allen.in Grignard's Reagent JEE (Main) Practice Paper Q. 1 2 3 4 5 6 7 8 9 10 A. 2 1 3 2 4 4 1 2 3 3 Section-A Q. 11 12 13 14 15 16 17 18 19 20 A. 1 4 2 4 1 3 4 4 1 2 Q. 1 2 3 4 5 6 7 8 9 10 Section-B A. 2 32 3 4 8 2 6 5 2 3 JEE (Advanced) Practice Paper Q. 1 2 3 4 Section-I A. C B A D Q. 5 6 7 8 9 10 Section-II A. AB ABD ACD BD ABCD AD Q. 11 12 Section-III A. A A Q. 13 14 15 16 Section-IV A. C B A C Q. 17 18 Section-V A. 3 5 www.allen.in [ 303 ]  JEE (Main + Advanced) : Chemistry Important Notes [ 304 ] www.allen.in