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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
The compound prepared by a substitution by a substitution reaction of benzene is :A. acetophenoneB. glyoxalC. CycloocatetraeneD. hexabromocyclohexane |
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Answer» Correct Answer - a |
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| 152. |
Benzene gives mainly :A. substituion reactionB. addition reactionC. eliumaination reactionD. all of these |
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Answer» Correct Answer - a |
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| 153. |
The carbon carbon bond length in benzene isA. `"same as in "C_(2)H_(4)`B. `"in between" C_(2)H_(6) "and " C_(2)H_(2)`C. `"in between " C_(2)H_(6)" and " C_(2)H_(4)`D. `"in between " C_(2)H_(4) " and " C_(2)H_(2)` |
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Answer» Correct Answer - c |
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| 154. |
The carbon-carbon bond length in benzene molecule is:A. 1.54 AB. 1.39 AC. 1.33 AD. 1.20 A |
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Answer» Correct Answer - b |
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| 155. |
Six carbon atoms of benzene are of:A. one typeB. two typesC. three typesD. six types |
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Answer» Correct Answer - a |
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| 156. |
The ring structure of benzene was first proposed by :A. WohlerB. FaradayC. KekuleD. Baeyer |
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Answer» Correct Answer - c |
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| 157. |
The centric formula of benzene was proposed byA. DewarB. Baeyer and ArmstrongC. LadenbergD. Kekule |
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Answer» Correct Answer - b |
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| 158. |
How many `120^(@)` angles does benzene molecule has ?A. 9B. 12C. 15D. 18 |
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Answer» Correct Answer - d |
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| 159. |
The number of `pi-"electrons"` in benzene molecule is :A. 6B. 3C. 5D. 4 |
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Answer» Correct Answer - a |
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| 160. |
The carbon-carbon bond order in benzene isA. 1B. between 1 and 2C. 1.5D. 2 |
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Answer» Correct Answer - b |
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| 161. |
The benzene molecule is :A. trigonalB. terahedralC. planarD. pyramidal |
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Answer» Correct Answer - c |
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| 162. |
The carbon atoms in benzene are :A. `sp^(2)-"hybridized"`B. sp-hydridizedC. `sp^(3)-"hybridized`D. non-hydridized |
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Answer» Correct Answer - a |
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| 163. |
The `C-C-C` bond angle in benzene isA. `90^(@)`B. `60^(@)`C. `109^(@)`D. `120^(@)` |
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Answer» Correct Answer - d |
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| 164. |
The following reaction is an example of : A. Wurtz reactionB. kolbe electrolysisC. Friedels - Crafts reactionD. Grignard synthesis |
| Answer» Correct Answer - C | |
| 165. |
Why is benzene extra ordinarily stable though it contains three double bonds ? |
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Answer» Correct Answer - Extra stability of benzene is due to its resonance stabilization. `(##GRB_ORG_CHM_P1_C08_E01_009_S01##)` `pi= " electrons present in the ring are delocalised, hence it is highly stable, though it contains three double bonds. |
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| 166. |
A benzene ring deactivated by strong and moderate electron withdrawing group that is, any meta directing group, is not electron rich enough to undergo Friedel-Crafts ranctions. Friedel-Crafts reaction also do not occur with `HN_(2)` group as it react with `AICI_(3)` and produce deactivating group. Answer the following question : Which of the following cannot be starting for this compound `Ph-underset(O)underset(||)(C)-CH_(2)-Ph ?`A. B. C. D. |
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Answer» Correct Answer - c |
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| 167. |
Which of the following froups groups deactivates the benzene ring towards electrophilic substitution ?A. `-NHR`B. `-OH`C. `-COOR`D. `-OR` |
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Answer» Correct Answer - c |
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| 168. |
Which of the following substituents deactivates the benzene ring towards electrophilic substitution?A. `-NHCH_(3)`B. `-OH`C. `-OCH_(3)`D. `-COOCH_(3)` |
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Answer» Correct Answer - D The groups `-overset(..)(N)HCH_(3)` and `-underset(..)overset(..)(O)H` are strongly activating group `-overset(..)underset(..)(O)CH_(3)` is moderately activating but group `-overset(O)overset(||)(C)-OCH_(3)` is moderately deactivating due to its `-I_("effect")` as well as `-R_("effect")` |
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| 169. |
The function of anhydrous `AlCl_(3)` in Friedel- Carfts reaction is to :A. absorb waterB. produce a nucleophileC. produce an electrophileD. absorb HCl |
| Answer» Correct Answer - C | |
| 170. |
Consider the following compounds The relative reactivity towards halonium ions is such that :A. ` I gt II gt III`B. `II gt I gt III`C. `II gt III gt I`D. `III gt I gt II` |
| Answer» Correct Answer - B | |
| 171. |
Explain the following with proper reasoning : (a) Although benzene is highly unsatureted, it does not undergo addition reactions. (b) Benzene though unsaturated, undergoes substitutions reactions easily reather than addition. ( c) All m-directors are deactivating. (d) The halogens, as exceptions, are o-p-directors but are deactivating. ( e) Most o- p-directing substituents are activating. |
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Answer» (a) `pi="electrons"` of benzene ring are dilocali-zed throughout the molecule. This makes the molecule very stable. The addition reactions would result in the breaking of this delocalization, i.e., the stability of the molecule which is resisted. (b) Resonace is present in benzene molecule. This makes the benzene molecule stable. As the substitution reactions do not disturb the resonance stabilization or aromatic character, thus, there reactions are resisted. ( c) The meta-directing substituents withdraw electrons form the benzene ring and thus, deactivate the benzene ring for further substitution. (d) In the case of halogens, two opposing effects operate simultaneously. A halogen substitument releases electrons due to resonance but withdraw wlwtrons also due to high electronegativityt, i.e., -I (inductive) effect. The inductive effect dominates more than the resonance effect. The inductive effect dominates more than the resonance effect and the net result is that the benzene ring is redered electron deficient and thus deactivated for further substitution. ( e) the o-, p-directing substituents release eletrons into the benzene ring and thus, activate the banzene ring for further substitution. |
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| 172. |
The presence of which one of the following group on benzene nucleus activate it towards electrophilic substitution :A. `- C-=N`B. `-overset(O)overset(||)(C)-H`C. `-overset(O)overset(||)(C)-OR`D. `- O - overset(O)overset(||)C - R` |
| Answer» Correct Answer - D | |
| 173. |
The reaction least likely to occur is :A. `C_(6)H_(6) + HNO_(3)overset(H_(2) SO_(4))to C_(6)H_(5)NO_(2)`B. `C_(6)H_(6) + H_(2)SO_(4) to C_(6)H_(5)SO_(3)H`C. `C_(6)H_(6)+ Br_(2) overset(Fe) C_(6)H_(5)Br`D. `C_(6)H_(6) _ Cl_(2) underset("light")overset(UV)toC_(6)H_(5)Cl` |
| Answer» Correct Answer - D | |
| 174. |
Which of the following compounds will not undergo Friedel`-` Crafts reaction easily ?A. XyleneB. NitrobenzeneC. TuleneD. Cumene |
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Answer» Correct Answer - B Friedel-crafts reaction is a typical electrophilic substitution reaction and nitro group in nitrobenzene is a powerful deactivator. |
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| 175. |
Which one of the following aromatic compojunds fails to undergo Friedel - crafts reactions ?A. `C_(5)H_(5)- CH_(3)`B. `C_(6)D_(6)`C. `C_(6)H_(5)-NO_(2)`D. `C_(6)H_(5)Cl` |
| Answer» Correct Answer - C | |
| 176. |
Styrene undergo following reactions in acidic medium The various intermadite formed are :A. B. C. D. |
| Answer» Correct Answer - A::B::C | |
| 177. |
Which of the following reactions give aromatic ion ?A. B. C. D. |
| Answer» Correct Answer - B::C::D | |
| 178. |
Which of the following sequence of reactions can gives A. B. C. D. `PhMgBrunderset(H^(o+)//H_(2)O)overset(CO_(2))tounderset(AlBr_(3))overset(Br_(3))to` |
| Answer» Correct Answer - B::C | |
| 179. |
Which of the following reactionsA. B. C. D. |
| Answer» Correct Answer - A::C::D | |
| 180. |
The reaction produces:A. B. C. D. |
| Answer» Correct Answer - B::D | |
| 181. |
Identify number of reaction that can gives nucleophilic aromatic substitution products |
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Answer» Correct Answer - 4 |
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| 182. |
Find out correct statement regarding nucleophilic aromatic substitution reaction :A. there should strong electron withdarwing group at ortho and para position with respect to leaving groupB. nucleophilic atom should be of N, S,O etc.C. rate of reaction is faster with fluoro derivative .D. all are incorrect. |
| Answer» Correct Answer - A::C::D | |
| 183. |
Which pairs are not required for a nucleophilic aromatic substitution reaction ?A. An `-NO_(2)` substituent and a strong electrophile.B. A ring bearing a strong activating group and a strong acid.C. A aryl halide with an- `NO_(2)` and a strong nucelophileD. An unsubstituted benzene ring and a strong eletrophile. |
| Answer» Correct Answer - A::B::C | |
| 184. |
Among the following copounds that can be most readily sulphonated is :A. B. C. D. |
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Answer» Correct Answer - d |
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| 185. |
Benzene reacts with `Cl_(2)` in the presence of `FeCl_(3)` and in absecne of sunlight to from :A. benzyl cholrideB. benzal chlorideC. chlorobenzeneD. benzenehexa chloride |
| Answer» Correct Answer - C | |
| 186. |
Phenolic esters heating with `AlCl_(3)` (Lewis acid ) gives ortho and para acyl phenol . This is known as Fries rearrangement . In general, low temperature favours the para product and high tempearture favaous orhto product . Mechanism : If one of the ortho position is subtituted by any group then para is the major product A. B. C. D. |
| Answer» Correct Answer - A | |
| 187. |
Phenolic esters heating with `AlCl_(3)` (Lewis acid ) gives ortho and para acyl phenol . This is known as Fries rearrangement . In general, low temperature favours the para product and high tempearture favaous orhto product . Mechanism : If one of the ortho position is subtituted by any group then para is the major product `underset(H_(2)O)overset(AlCl_(3))to` Major product :A. B. C. D. |
| Answer» Correct Answer - C | |
| 188. |
Phenolic esters heating with `AlCl_(3)` (Lewis acid ) gives ortho and para acyl phenol . This is known as Fries rearrangement . In general, low temperature favours the para product and high tempearture favaous orhto product . Mechanism : If one of the ortho position is subtituted by any group then para is the major product `overset(AlCl_(3))to ` Major product :A. B. C. D. |
| Answer» Correct Answer - B | |
| 189. |
A and B are :A. identicalB. positional isomersC. geometrical isomersD. none the these |
| Answer» Correct Answer - B | |
| 190. |
Which of the following are antiaromatic?A. (i) and (ii)B. (ii) and (iii)C. (iii) and (iv)D. (i) and (iv) |
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Answer» Correct Answer - 4 Both (i) and (iv) have `4npie^(-)s` and hence,are antiaromatic while (i) and (iii) are aromatic as they have`(4n+2)pie^(-)s`. |
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| 191. |
Which of the following species are antiaromatic ? A. III and IVB. I and IIIC. I and IID. I and IV |
| Answer» Correct Answer - A | |
| 192. |
`C_(6)H_(6)+CO+HCloverset("Anhy. AlCl"_(3))rarrX+HCl` compound X isA. `C_(6)H_(5)CHO`B. `C_(6)H_(5)COOH`C. `C_(6)H_(5)CH_(2)CI`D. `C_(6)H_(5)CH_(3)` |
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Answer» Correct Answer - a |
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| 193. |
An organic compound A on treatment with `CHCl_(3)` and KOH gives B and C, both of which, in turn, gives the same compound D when distilled with Zn dust. Oxidation of D yields E of the fromula `C_(7)H_(6)O_(2)`. The Na salt of E on heating with soda lime give F which can be also be obtained by distilling A with Zn dust Identify F.A. B. C. D. |
| Answer» Correct Answer - D | |
| 194. |
Which one of the following is the strongest acid?A. B. C. D. |
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Answer» Correct Answer - C The carbocation derived from this compound is aromatic `(10pie^(-))` and hence is unusually stable. |
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| 195. |
In which of the following cases nitration will be take place at m-position ? A. I onlyB. II, III and IVC. I, III and IVD. I,II and III |
| Answer» Correct Answer - D | |
| 196. |
, this reaction proceed throught :A. electrophilic additionB. benzyne intermediateC. nucleophilic aromaticD. oixirane |
| Answer» Correct Answer - C | |
| 197. |
A, A can be :A. B. C. D. no reaction |
| Answer» Correct Answer - B | |
| 198. |
underset(100^(@))overset(H_(2)("1 atm"), Pd)toA `, Product A is the reaction is :A. B. C. D. all of these |
| Answer» Correct Answer - B | |
| 199. |
`underset("dry ether " )overset("Mg")toA`, Identify A :A. B. C. D. |
| Answer» Correct Answer - D | |
| 200. |
Toluene reagent for nuclear iodination of aromatic compound is :A. benzyl chlorideB. banzoyl chlorideC. p-chlorotolueneD. p-chlorotoluene |
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Answer» Correct Answer - a |
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