Hydrocarbons PYQs Set 6 (PDF)

Set 6 of 16 · Questions 151-180 of 459

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Mere Teacher · Previous Year Questions JEE Main Chemistry · Hydrocarbons · Set 6 (Q151-180)
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151. $An alkene A on reaction with O_{3} and Z n - H_{2} O gives propanone and ethanal in equimolar ratio. Addition of HCl to alkene A gives B as the major product. The structure of product B is$ (1) $H_{3} C - C H (C l) - C H (C H_{3}) - C H_{3}$ (2) $C l - C H_{2} - C H_{2} - C H (C H_{3}) - C H_{3}$ (3) $H_{3} C - C H_{2} - C H (C H_{2} C l) - C H_{3}$ (4) $H_{3} C - C H_{2} - C (C H_{3}) (C l) - C H_{3}$ 152. $In the process of formation of nitronium ion, nitric acid acts as$ (1) $a base$ (2) $an acid$ (3) $a catalyst$ (4) $a solvent$ 153. $A compound is treated with N a N H_{2} to give sodium salt. Identify the compound.$ (1) $C_{2} H_{2}$ (2) $C_{6} H_{6}$ (3) $C_{2} H_{6}$ (4) $C_{2} H_{4}$ 154. $Predict the product C obtained in the following reaction of 1‐butyne.$ (1) $C H_{3} - C H_{2} - C H_{2} - C (I) (C l) - H$ (2) $C H_{3} - C H_{2} - C H (I) - C H_{2} - C l$ (3) $C H_{3} - C H_{2} - C (I) (C l) - C H_{3}$ (4) $C H_{3} - C H (C l) - C H_{2} - C H_{2} - I$ 155. $CH_{3} CH_{2} COO^{-} Na^{+} NaOH + ? Heat CH_{3} - CH_{3} + Na_{2} CO_{3} Consider the above reaction and Identify the missing reagent/chemical.$ (1) $B_{2} H_{6}$ (2) $Red. phosphorus$ (3) $CaO$ (4) $DIBAL-H$ 156. $The compound or ion which is not aromatic in the following is$ (1) (2) (3) (4) 157. $Which one of the following conformations of cyclohexane is the least stable?$ (1) $Half-chair$ (2) $Boat$ (3) $Twisted-boat$ (4) $Chair$ 158. $In which of the following reactions, t -butyl benzene is formed 1.Benzene + t -butyl chloride \to AlCl 3 2.Benzene + (CH_{3})_{2} C = CH_{2} \to BF 3. HF 3.Benzene + t -butyl alcohol \to H 2 SO 4 4.Benzene + butanoyl chloride \to AlCl 3 Zn / HCl$ (1) $1,2 and 3$ (2) $2,3 and 4$ (3) $1,2 and 4$ (4) $1,3 and 4$ 159. $Addition of HBr to propene in presence of a peroxide takes place contrary to Markovnikov rule. This can be explained by the mechanism involving$ (1) $electrophile$ (2) $free radical$ (3) $nucleophile$ (4) $carbene$ 160. $When n -hexane is heated with anhydrous AlCl_{3} and HCl gas, the major product(s) obtained is/are$ (1) $mixture of 2-methylpentane and 3-methylpentane$ (2) $2-chlorohexane$ (3) $3-chlorohexane$ (4) $hex-3-ene.$ 161. $Benzene reacts with n -propyl chloride in the presence of anhydrous AlCl_{3} to give predominantly$ (1) $n -propyl benzene$ (2) $isopropyl benzene .$ (3) $3-propyl-1-chloro benzene$ (4) $1-chloro-3-n-propyl benzene$ 162. $Which of the following compounds is most basic ?$ (1) (2) (3) (4) $None of these$ 163. $An unsaturated hydrocarbon X on ozonolysis gives A . Compound A when warmed with ammonical silver nitrate forms a bright silver mirror along the sides of the test tube. The unsaturated hydrocarbon X is:$ (1) $C H_{3} - C (C H_{3}) = C (C H_{3}) - C H_{3}$ (2) (3) $HC \equiv C - CH_{2} - CH_{3}$ (4) $CH_{3} - C \equiv C - CH_{3}$ 164. $In the hydrocarbon, The state of hybridization of carbons 1, 3 and 5 are in the following sequence$ (1) $s p, s p^{2}, s p^{3}$ (2) $s p^{3}, s p^{2}, s p$ (3) $s p^{2}, s p, s p^{3}$ (4) $s p, s p^{3}, s p^{2}$ 165. $Find out the hybridisations of C_{1}, C_{2} and C_{3} labelled carbon atoms in the given molecule$ (1) $C_{1} C_{2} C_{3} sp s p^{2} s p^{2}$ (2) $C_{1} C_{2} C_{3} sp s p^{2} sp$ (3) $C_{1} C_{2} C_{3} s p^{2} sp sp$ (4) $C_{1} C_{2} C_{3} s p^{2} s p^{2} s p^{2}$ 166. $Arrange the following in increasing order of reactivity towards nitration A. p-xylene B. bromobenzene C. mesitylene D. nitrobenzene E. benzene Choose the correct answer from the options given below$ (1) $C<D<E<A<B$ (2) $D<B<E<A<C$ (3) $D<C<E<A<B$ (4) $C<D<E<B<A$ 167. $A compound 'X' on treatment with B r_{2} /NaOH, provided C_{3} H_{9} N, which gives positive cabylamine test. Compound 'X' is$ (1) $C H_{3} C O C H_{2} N H C H_{3}$ (2) $C H_{3} CON (C H_{3})_{2}$ (3) $C H_{3} C H_{2} C O C H_{2} N H_{2}$ (4) $C H_{3} C H_{2} C H_{2} C O N H_{2}$ 168. $Which of the following compounds will form significant amount of meta product during mono-nitration reaction ?$ (1) (2) (3) (4) 169. $Identify Z in the sequence of reactions : CH_{3} CH_{2} CH = CH_{2} HBr H_{2} O_{2} Y C_{2} H_{5} ONa Z$ (1) $CH3-(CH2)3-O-CH2CH3$ (2) $(CH3)2CH2-O-CH2CH3$ (3) $CH3(CH2)4-O-CH3$ (4) $CH3CH2-CH(CH3)-O-CH2CH3$ 170. $Dihedral angle (D.A.) of least stable conformer of ethane is$ (1) $120^{\circ}$ (2) $180^{\circ}$ (3) $60^{\circ}$ (4) $0^{\circ}$ 171. $In the above reaction electrophile is substituted at meta position only, due to I. Electron density is more at ortho & para position II. Electron density is relatively less at ortho & para position III. Electron density is less at meta position IV. Electron density is relatively more at meta position Correct answer is$ (1) $I, III only$ (2) $II, IV only$ (3) $1 only$ (4) $III only$ 172. $2-Butyne is reduced to trans-but-2-ene using$ (1) $H_{2} / Ni$ (2) $Na in liq. NH_{3}$ (3) $H_{2} / Pd - C$ (4) $Zn in dil. HCl .$ 173. $Which of the following is a free radical substitution reaction?$ (1) $Acetylene with HBr$ (2) $Methane with Br_{2} / hv$ (3) $Propene with HBr / (C_{6} H_{5} COO)_{2}$ (4) $Benzene with Br_{2} / AlCl_{3}$ 174. $H_{2} + CO + alkene \to catalyst 1^{\circ} alcohol. What is the stable intermediate and the nature of the reaction?$ (1) $Acid, reduction$ (2) $Aldehyde, oxidation$ (3) $Aldehyde, reduction$ (4) $Alcohol, oxidation$ 175. $Which of the following compound is most reactive in electrophilic aromatic substitution?$ (1) $nitrobenzene$ (2) $benzene$ (3) $phenol$ (4) $chlorobenzene$ 176. $Which of the following is not obtained when a mixture of methyl chloride and n -propyl chloride is treated with sodium metal in dry ether?$ (1) $Ethane$ (2) $Propane$ (3) $Butane$ (4) $Hexane$ 177. $The reaction, C H_{2} = C H - C H_{3} + H B r \to C H_{3} C H B r - C H_{3} is$ (1) $electrophilic substitution$ (2) $free radical addition$ (3) $nucleophilic addition$ (4) $electrophilic addition.$ 178. $The correct increasing order of reactivity for the following molecules towards electrophilic aromatic substitution is :$ (1) $I < IV < II < III$ (2) $I < IV < III < II$ (3) $I < III < II < IV$ (4) $I < III < IV < II$ 179. $The reactivity of compound Z with different halogens under appropriate conditions is given below : The observed pattern of electrophilic substitution can be explained by$ (1) $the steric effect of the halogen$ (2) $the steric effect of the tert-butyl group$ (3) $the electronic effect of the phenolic group$ (4) $the electronic effect of the tert-butyl group$ 180. $Consider the following chemical reaction. HC \equiv CH (1) Red hot Fe tube, 873 K (b) CO + HCl / AlC l_{3} Product The number of sp^{2} hybridized carbon atom(s) present in the product is:$