Haloalkanes & Haloarenes PYQs Set 2 (PDF)

Set 2 of 9 · Questions 31-60 of 261

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Mere Teacher · Previous Year Questions NEET Chemistry · Haloalkanes & Haloarenes · Set 2 (Q31-60)
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31. $Reaction of methyl bromide with aqueous sodium hydroxide involves$ (1) $racemisation$ (2) $S_{N} 1 mechanism$ (3) $inversion of configuration$ (4) $none of the above$ 32. $Given below are two statements: Statement - I: High concentration of strong nucleophilic reagent with secondary alkyl halides which do not have bulky substituents will follow S_{N} 2 mechanism. Statement - II: A secondary alkyl halide when treated with a large excess of ethanol follows S_{N} 1 mechanism. In the the light of the above statements, choose the most appropriate from the questions given below:$ (1) $Statement I is true but Statement II is false.$ (2) $Statement I is false but Statement II is true.$ (3) $Both statement I and Statement II are false.$ (4) $Both statement I and Statement II are true.$ 33. $Which of the following reaction is NOT correctly represented?$ (1) $C_{6} H_{5} CH_{3} Br_{2}, Fe dark ortho and para Bromotoluenes$ (2) $C_{6} H_{5} N_{2}^{+} Cl^{-} Cu_{2} Br_{2} / HBr C_{6} H_{5} Br$ (3) $C_{6} H_{5} CH_{3} Br_{2}, h ν C_{6} H_{5} CH_{2} Br$ (4) $3-methylcyclohexene Br_{2}, h ν 3-(bromomethyl)cyclohexene$ 34. $Which among the following will have highest density?$ (1) $CCl_{4}$ (2) $n - C_{3} H_{7} I$ (3) $n - C_{3} H_{7} Br$ (4) $n - C_{3} H_{7} Cl$ 35. $Which of the following is an organometallic compound?$ (1) $CH_{3} COONa$ (2) $(CH_{3} COO)_{2} Ca$ (3) $CH_{3} CH_{2} MgBr$ (4) $CH_{3} ONa$ 36. $Methyl bromide is converted into ethane by heating it in ether medium with$ (1) $Al$ (2) $Zn$ (3) $Na$ (4) $Cu.$ 37. $Which of the following halide shows highest reactivity towards S_{N} 1 reaction?$ (1) $CH_{3} - CH_{2} Cl$ (2) $CH_{3} - CH_{2} - CH_{2} - CH_{2} I$ (3) $C_{6} H_{5} Cl$ (4) $C_{6} H_{5} CH_{2} Cl$ 38. $If ' n' represents total number of asymmetric carbon atoms in a compound, the possible number of optical isomers of the compound is$ (1) $2 n$ (2) $n^{2}$ (3) $2^{n}$ (4) $2 n + 2$ 39. $Which of the following pairs are correctly matched? Reactants Products I. RX + AgOH_{(aq)} RH II. RX + AgCN_{(alc)} RNC III. RX + KCN_{(alc)} RNC IV. RX + Na_{(ether)} R - R$ (1) $I alone$ (2) $I and II$ (3) $II and III$ (4) $II and IV$ 40. $Identify the halogen exchange reaction from the following$ (1) $Sandmeyer reaction$ (2) $Swarts reaction$ (3) $Stephens reaction$ (4) $Wurtz reaction$ 41. $Least reactive alkyl chloride in a S_{N} 2 reaction is$ (1) $1-Chloro butane$ (2) $1-Chloro 2-Methyl propane$ (3) $2-Chloro 2-Methyl propane$ (4) $2-Chloro butane$ 42. $Which reaction is useful in exchange of halogen in alkyl chloride by iodide?$ (1) $Wurtz reaction$ (2) $Finkelstein reaction$ (3) $Reimer-Tiemann reaction$ (4) $Williamson synthesis$ 43. $Choose the correct decreasing order of reactivity of alkyl halides towards S_{N} 1 reaction.$ (1) $Primary halide > Secondary halide > Tertiary halide$ (2) $Secondary halide > Tertiary halide > Primary halide$ (3) $Tertiary halide > Secondary halide > Primary halide$ (4) $Tertiary halide > Primary halide > Secondary halide$ 44. $Which of the following biphenyls is optically active?.$ (1) (2) (3) (4) 45. $The reaction of C_{6} H_{5} CH = CHCH_{3} with HBr produces [AIPMT 2015]$ (1) $C_{6} H_{5} CH CH_{2} CH_{3} \| Br$ (2) $C_{6} H_{5} CH_{2} CH CH_{3} \| Br$ (3) $C_{6} H_{5} CH_{2} CH_{2} CH_{2} Br$ (4) 46. $The correct sequence of bond enthalpy of C - X bond [NEET 2024]$ (1) $CH_{3} - Cl > CH_{3} - F > CH_{3} - Br > CH_{3} - I$ (2) $CH_{3} - F < CH_{3} - Cl < CH_{3} - Br < H_{3} - I$ (3) $CH_{3} - F > CH_{3} - Cl > CH_{3} - Br > CH_{3} - I$ (4) $CH_{3} - F < CH_{2} Cl > CH_{3} - Br > CH_{3} - I$ 47. $1-chloro butane on treatment with alcoholic potash forms\dots\dots\dots..$ (1) $2-butanol$ (2) $1-butene$ (3) $1-butanol$ (4) $2-butene$ 48. $The products A and B obtained in the following reactions, respectively are [NEET 2024] 3 ROH + PCl_{3} ⟶ 3 RCl + A ROH + PCl_{5} ⟶ Cl + HCl + B$ (1) $POCl_{3} and H_{3} PO_{3}$ (2) $POCl_{3} and H_{3} PO_{4}$ (3) $H_{3} PO_{4} and POCl_{3}$ (4) $H_{3} PO_{3} and POCl_{3}$ 49. $Which of the following undergoes nucleophilic substitution exclusively by S_{N} 1 mechanism?$ (1) $Ethyl chloride$ (2) $Isopropyl chloride$ (3) $Chlorobenzene$ (4) $Benzyl chloride$ 50. $In an S_{N} 1 reaction on chiral centers, there is [NEET 2025]$ (1) $inversion more than retention leading to partial racemization$ (2) $100 % retention$ (3) $100 % inversion$ (4) $100 % racemisation$ 51. $The hydrolysis reaction that takes place at the slowest rate, among the following is$ (1) (2) $H_{3} C - C H_{2} - C l a q . N a O H C H_{3} - C H_{2} - O H$ (3) $H_{2} C = C H - C H_{2} O H$ (4) 52. $Which of the following reaction represents swarts reaction?$ (1) $CH_{3} - CH_{2} - Br \to CoF 2$ (2) $CH_{3} - CH_{2} - Br \to NaI dry acetone$ (3) (4) 53. $Polysubstitution is a major drawback in :$ (1) $Friedel Craft’s alkylation$ (2) $Reamer Tiemann reaction$ (3) $Acetylation of aniline$ (4) $Friedel Craft’s acylation$ 54. $Which chloro derivative of benzene among the following would undergo hydrolysis most readily with aqueous sodium hydroxide to turnish the corresponding hydroxy derivative? [NEET 2017]$ (1) (2) (3) (4) $C_{6} H_{5} Cl$ 55. $Assertion (A) : I- Bromopentane reacts with AgCN to give pentylisocyanideReason ( R ) : AgCN is mainly ionic in nature$ (1) $A is true, R is true and R is correct explanation of A$ (2) $A is true, R is true but R is not correct explanation of A$ (3) $A is true, R is false$ (4) $A is false, R is true$ 56. $An organic compound on heating with CuO produces CO_{2} but no water. The organic compound may be$ (1) $chloroform$ (2) $methane$ (3) $ethyl iodide$ (4) $carbon tetrachloride.$ 57. $Which one of the following has highest boiling point?$ (1) $H_{3} CCH_{2} CH_{2} CH_{2} Cl$ (2) $(H_{3} C)_{2} CHCH_{2} Cl$ (3) $(H_{3} C)_{3} CCl$ (4) $H_{3} C C H_{2} C H (C l) C H_{3}$ 58. $Following is the substitution reaction in which - CN replaces - Cl . R - Cl + KCN (alcoholic) R - CN + KC l To obtain propanonitrile, R - Cl should be$ (1) $chloroethane$ (2) $1-chloropropane$ (3) $chloromethane$ (4) $2-chloropropane.$ 59. $Identify the correct products, when ethanol reacts with PCl_{5}$ (1) $Chloroethane, Hydrochloric acid and Phosphorus acid$ (2) $Chloroethane, Hydrochloric acid and Phosphoric acid$ (3) $Chloroethane, Sulfuric acid and Phosphorous oxy chloride$ (4) $Chloroethane, Hydrochloric acid and Phosphorous oxy chloride$ 60. $The structure of the major product formed in the following reaction is: \to AgCN major product$ (1) (2) (3) (4)