Hydrocarbons PYQs Set 3 (PDF)

Set 3 of 15 · Questions 61-90 of 435

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Mere Teacher · Previous Year Questions NEET Chemistry · Hydrocarbons · Set 3 (Q61-90)
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61. $Identify the correct statements : The presence of - NO_{2} group in benzene ring(A) activates the ring towards electrophilic substitutions.(B) deactivates the ring towards electrophilic substitutions.(C) activates the ring towards nucleophilic substitutions.(D) deactivates the ring towards nucleophilic substitutions. Choose the correct answer from the options given below:$ (1) $(C) and (A) Only$ (2) $(B) and (C) Only$ (3) $(A) and (D) Only$ (4) $(B) and (D) Only$ 62. $The electrophile involved in the sulphonation of benzene is$ (1) $SO_{3}^{2 -}$ (2) $H_{3} O^{+}$ (3) $SO_{3}$ (4) $SO_{3}^{+}$ 63. $Method by which Aniline cannot be prepared is :$ (1) $hydrolysis of phenylisocyanide with acidic solution$ (2) $degradation of benzamide with bromine in alkaline solution$ (3) $reduction of nitrobenzene with H2/Pd in ethanol$ (4) $potassium salt of phthalimide treated with chlorobenzene followed by hydrolysis with aqueous NaOH solution.$ 64. $Which one of the following is not formed when a mixture of methyl bromide and bromobenzene is heated with sodium metal in the presence of dry ether?$ (1) $Ethane$ (2) $Diphenyl$ (3) $Propane$ (4) $Toluene$ 65. $Peroxide effect is observed with the addition of HBr but not with the addition of HI to unsymmetrical alkene because$ (1) $H - I bond is stronger than H - Br and is not cleaved by the free radical$ (2) $H - I bond is weaker than H - Br bond so that iodine free radical combine to form iodine molecules$ (3) $bond strength of HI and HBr are same but free radicals are formed in HBr$ (4) $all of these.$ 66. $Which of the following compound will most easily be attacked by an electrophile?$ (1) (2) (3) (4) 67. $The correct order of reactivity of hydrogen halides with propene is$ (1) $HCl > HBr > HI$ (2) $HBr > HI > HCl$ (3) $HI > HBr > HCl$ (4) $HCl > HI > HBr$ 68. $The compound that reacts the fastest with sodium methoxide is$ (1) (2) (3) (4) 69. $Identify the starting compound ' P^{’} in the following reaction. P \to Na / dryether (H_{3} C)_{2} CHCH_{2} CH_{2} CH (CH_{3})_{2}$ (1) $1-Bromo-2-methylpropane$ (2) $1-Bromobutane$ (3) $2-Brom propene$ (4) $2-Bromobutane$ 70. $In preparation of alkene from alcohol using A 1_{2} O_{3} which is the effective factor$ (1) $Porosity of A 1_{2} O_{3}$ (2) $Temperature$ (3) $Concentration$ (4) $Surface area of A 1_{2} O_{3}$ 71. $Which of the following compounds will exhibit c i s ‐trans (geometrical) isomerism?$ (1) $Butanol$ (2) $2‐Butyne$ (3) $2‐Butenol$ (4) $2‐Butene$ 72. $Which of the following can be used as the halide component for Friedel-Craftts reaction?$ (1) $Chlorobenzene$ (2) $Bromobenzene$ (3) $Chloroethene$ (4) $Isopropyl chloride$ 73. $In the Kolbe electrolysis of sodium propanoate, the products X and Y are formed at respected electrodes. What are X and Y ?$ (1) $X = CH_{3} - CH_{2} - CH_{2} - CH_{3} at Cathode; Y = H_{2} at Anode$ (2) $X = CH_{3} - CH_{2} - CH_{3} at Cathode; Y = H_{2} at Anode$ (3) $X = CH_{3} - CH_{2} - CH_{2} - CH_{3} at Anode; Y = H_{2} at Cathode$ (4) $X = CH_{3} - CH_{3} at Anode; Y = H_{2} at Cathode$ 74. $Assertion (A): Sodium acetate on Kolbe's electrolysis gives ethane. Reason (R): Methyl free radical is formed at cathode.$ (1) $Both A and R are true and R is a correct explanation of A .$ (2) $Both A and R are true but R is not a correct explanation of A .$ (3) $A is true but R is false.$ (4) $A is false but R is true.$ 75. $2‐Butene shows geometrical isomerism due to$ (1) $restricted rotation about double bond$ (2) $free rotation about double bond$ (3) $free rotation about single bond$ (4) $chiral carbon.$ 76. $The alkyl halides required to prepare by Wurtz reaction are$ (1) (2) (3) (4) 77. $Sodium acetate was electrolysed by Kolbe's method to form two gases A and B at anode. C and D are formed, when B is heated with regulated supply of O_{2} or air in the presence of (CH_{3} COO)_{2} Mn . C reacts with NaOH to form a salt. A and D are respectively,$ (1) $CO_{2}, CH_{3} COOH$ (2) $CO_{2}, H_{2} O$ (3) $C_{2} H_{6}, H_{2} O$ (4) $CO_{2}, H_{2} O_{2}$ 78. $The most suitable reagent for the following conversion, is: H_{3} C - C \equiv C - CH_{3} ⟶ cis-2-butene$ (1) $Na /liquid NH_{3}$ (2) $H_{2}, Pd / C, quinoline$ (3) $Zn / HCl$ (4) $Hg^{2 +} / H^{+}, H_{2} O$ 79. $Method used for separation of mixture of products (B and C) obtained in the following reaction is$ (1) $steam distillation$ (2) $simple distillation$ (3) $sublimation$ (4) $fractional distillation$ 80. $Among the following: The set which represents aromatic species is$ (1) $I, II and III$ (2) $III, IV and V$ (3) $II and III$ (4) $I, II and IV.$ 81. $Reduction of 2‐butyne with sodium in liquid ammonia gives predominantly$ (1) $cis‐2‐butene$ (2) $no reaction$ (3) $trans‐2‐butene$ (4) $n ‐butane.$ 82. $Among the following compounds (I‐III)the correct reaction with electrophile is$ (1) $1 > I I > 11 I$ (2) $I = I I > 1 I 1$ (3) $I I > I I I > I$ (4) $III < I < II$ 83. $Which one of the following alkenes will react faster with H_{2} under catalytic hydrogenation conditions?$ (1) (2) (3) (4) $(= alkyl substituent)$ 84. $In electrophilic aromatic substitution reaction, the nitro group is meta directing because it$ (1) $decreases electron density at meta position$ (2) $increases electron density at meta position$ (3) $increases electron density at ortho and para positions$ (4) $decreases electron density at ortho and para positions.$ 85. $In the Hofmann bromamide degradation reaction, the number of moles of NaOH and B r_{2} used per mole of amine produced are :$ (1) $Four moles of NaOH and two moles of B r_{2}$ (2) $Two moles of NaOH and two moles of B r_{2}$ (3) $Four moles of NaOH and one mole of B r_{2}$ (4) $One mole of NaOH and one mole of B r_{2}$ 86. $C H_{3} N H_{2} + C H C I_{3} + KOH \to Nitrogen containing compound + KCI + H_{2} O. Nitrogen containing compound is :$ (1) $CH3-C\equivN$ (2) $C H_{3} -NH- C H_{3}$ (3) $C H_{3} - N^{-} \equiv C^{+}$ (4) $C H_{3} - N^{+} \equiv C^{-}$ 87. $In Friedel‐Crafts alkylation, besides A l C 1_{3} the other reactants are$ (1) $C_{6} H_{6} + C H_{3} C 1$ (2) $C_{6} H_{6} + C H_{4}$ (3) $C_{6} H_{6} + N H_{3}$ (4) $C_{6} H_{6} + C H_{3} C O C 1$ 88. $In pyrrole the electron density is maximum on$ (1) $2 and 3$ (2) $3 and 4$ (3) $2 and 4$ (4) $2 and 5$ 89. $The structure of the compound that gives a tribromo derivative on treatment with bromine water is$ (1) (2) (3) (4) 90. $Given below are two statements: Statement I: Ozonolysis followed by treatment with Zn, H_{2} O of cis-2-butene gives ethanal. Statement II: The product obtained by ozonolysis followed by treatment with Zn, H_{2} O of 3, 6-dimethyloct-4-ene has no chiral carbon atom. In the light of the above statements, choose the correct answer from the options given below$ (1) $Statement I is false but Statement II are true$ (2) $Both Statement I and Statement II are$ (3) $Statement I is true but Statement II is false$ (4) $Both Statement I and Statement II are true$