Description : Which one of the following is most reactive towards nucleophilic substitution reaction ?
Last Answer : Which one of the following is most reactive towards nucleophilic substitution reaction ? A. `H_(2)C=CH-Cl` B. ` ... 3)CH=CHCl` D. `ClCH_(2)-CH=CH_(2)`
Description : Aryl halides are less reactive towards nucleophilic substitution as compared to alkyl halides due to (a) Inductive effect (b) Resonance stabilization (c) Tautomerism (d) Stereoisomerism
Last Answer : Resonance stabilization
Description : Assertion: Phenol is more reactive than benzene towards electrophilic reactions. Reason : The +R effect of OH group increases the electron density on
Last Answer : Assertion: Phenol is more reactive than benzene towards electrophilic reactions. Reason : The +R effect of ... D. A is incorrect but R is correct
Description : Acetyl chloride undergoes nucleophilic substitution at a faster rate than methyl acetate because __________. (a) the ester is more sterically hindered than the acid chloride (b) the acid chloride is ... is a better leaving group than chloride (d) chloride is a better leaving group than methoxide
Last Answer : chloride is a better leaving group than methoxide
Description : Which of the following is least reactive in a nucleophilic substitution reaction?
Last Answer : Which of the following is least reactive in a nucleophilic substitution reaction? A. `(CH_(3))_(3)C-Cl` B. `CH_ ... 3)CH_(2)Cl` D. `CH_(2)=CHCH_(2)Cl`
Description : Ethylene is obtained from ethyl bromide by : (a) Simple heating (b) Hydrolysis (c) Dehydrohalogenation (d) Nucleophilic substitution
Last Answer : Dehydrohalogenation
Description : Why do aldehydes undergo nucleophilic addition reactions while esters undergo nucleophilic acyl substitution reactions? (a) The carbonyl carbon of an ester is more electrophilic than that of an aldehyde. (b) ... adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic
Last Answer : Once the nucleophile adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic
Description : Which of the following can undergo nucleophilic substitution under ordinary conditions? I Allyl chloride II Benzyl chloride III n-Propyl chloride IV V
Last Answer : Which of the following can undergo nucleophilic substitution under ordinary conditions? I Allyl chloride II ... are correct D. I and III are correct
Description : Explain why nucleophilic substitution reactions are not very common in phenols.
Last Answer : Explain why nucleophilic substitution reactions are not very common in phenols.
Description : Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?
Last Answer : Ans. Due to the presence of an electron cloud containing 6 pi electrons above and below the plane of the ring, benzene is a source of electrons. Consequently, it attracts ... . As a result, benzene undergoes electrophilic substitution reactions easily and nucleophilic substitution with difficulty.
Description : Esters can be formed by nucleophilic substitution reactions of : (a) carboxylic acids and alcohols ; acid-catalyzed (b) acid chlorides and alcohols (c) both of the above (d) neither of the above
Last Answer : both of the above
Description : Esters and amides are most easily made by nucleophilic acyl substitution reactions on : (a) acid anhydrides (b) carboxylates (c) carboxylic acids (d) acid chlorides
Last Answer : acid chlorides
Description : Which of the following characterizes the reactions of aldehydes and ketones? (a) electrophilic addition (b) electrophilic substitution (c) nucleophilic acyl substitution (d) nucleophilic addition; free radical addition
Last Answer : nucleophilic addition; free radical addition
Description : Alkyl halides undergo (a) Electrophilic substitution reactions (b) Electrophilic addition reactions (c) Nucleophilic substitution reactions (d) Nucleophilic addition reactions
Last Answer : Nucleophilic substitution reactions
Description : Phenol is more reactive than benzene towards electrophilic substitution reaction. In case of Phenol, the intermediate carbocation is more resonance st
Last Answer : Phenol is more reactive than benzene towards electrophilic substitution reaction. In case of Phenol, the ... D. A is incorrect but R is correct
Description : Which of the following is not correct concerning substitution and elimination reactions of alkyl halides? (a) The electrophile replaces the leaving group. (b) Compounds containing electron-donating groups bonded to an ... replaced by another atom or group in substitution reactions. (d) (a) and (b)
Last Answer : (a) and (b)
Description : Which of the reactions between the following pairs of reagents proceeds by a mechanism that may be described as an electrophilic substitution? (a) Benzene + Br2/FeBr3 (b) Propene + Br2 (c) Acetone + NH2NH2 (d) Ethyl bromide + aq KOH
Last Answer : Benzene + Br2/FeBr3
Description : The monomer of poly vinyl chloride (PVC) is (A) Chloroethane (B) Ethylene dichloride (C) Ethyl chloride (D) Chloroform
Last Answer : (A) Chloroethane
Description : 1,2-Dichloroethane reacts with excess of NaNH2 to form (a) Vinyl chloride (b) Ethylene (c) Ethyl chloride (d) Acetylene
Last Answer : Acetylene
Description : Which of the following statements correctly describes the general reactivity of alkynes? (a) An alkyne is an electron-rich molecule and therefore reacts as a nucleophile. (b) The σ bonds ... fail to undergo electrophilic addition reactions. (d) Alkynes are generally more reactive than alkenes.
Last Answer : Alkynes are generally more reactive than alkenes.
Description : Which of the following undergoes nucleophilic substitution exclusively by `S_(N^(1))` mechanism?
Last Answer : Which of the following undergoes nucleophilic substitution exclusively by `S_(N^(1))` ... Isopropyl chloride C. Chlorobenzene D. Benzyl chloride
Description : Quinoline undergoes nucleophilic substitution on heating with NaNH2 to give (a) 2-Aminoquinoline (b) 4-Aminoquinoline (c) 3-Aminoquinoline (d) 8-Aminoquinoline
Last Answer : 2-Aminoquinoline
Description : Benzene reacts with concentrated HNO3 in the presence of concentrated H2SO4 to give nitrobenzene. This reaction is an example of (a) Electrophilic addition (b) Nucleophilic addition (c) Electrophilic substitution (d) Nucleophilic substitution
Last Answer : Electrophilic substitution
Description : The characteristic reaction of carboxylic acids is : (a) electrophilic addition (b) electrophilic substitution (c) nucleophilic addition (d) nucleophilic substitution
Last Answer : nucleophilic substitution
Description : Acetone reacts with HCN to form a cyanohydrin. It is an example of (a) Electrophilic addition (b) Electrophilic substitution (c) Nucleophilic addition (d) Nucleophilic substitution
Last Answer : Nucleophilic addition
Description : Which alkyl halides react most readily by nucleophilic substitution? (a) CH3CH2Cl (b) CH3CH2I (c) CH3CH2Br (d) CH3CH2F
Last Answer : CH3CH2I
Description : Propene reacts with bromine to form 1,2-dibromopropane. This is an example of (a) Nucleophilic addition (b) Electrophilic addition (c) Nucleophilic substitution (d) Electrophilic substitution
Last Answer : Electrophilic addition
Description : The chlorination of methane to give CCl4 is an example of (a) an electrophilic addition (b) a free-radical substitution (c) a nucleophilic addition (d) an electrophilic substitution
Last Answer : a free-radical substitution
Description : Phenol is an ortho-para director because the hydroxyl group : (a) donates electrons that increase electron density at ortho and para positions favoring nucleophilic attack. (b) donates ... para positions and attracts electrons away from meta positions favoring electrophilic attack on the ring.
Last Answer : donates electrons that increase electron density at ortho and para positions favoring electrophilic attack.
Description : Urea is prepared by the chemical reactions of (a) Ammonium sulphate and calcium chloride (b) Ammonia and carbon dioxide (c) Chlorine and water (d) Acetamide and ethyl alcohol
Last Answer : Ans: (b)
Description : How an — OH group attached to carbon in the benzene ring activates benzene towards electrophilic substitution ?
Last Answer : The lone pair of electrons present on oxygen atom enter into resonance with the benzene ring. As a result, the electron density becomes higher at o- and p- position and due to higher electron density, the ring gets activated towards electrophilic substitution.
Description : Which statement about the carbonyl group of ketones and aldehydes is true? I. It can attract nucleophiles. II. It can attract electrophiles. III. It tends to undergo addition reactions. IV. It tends to undergo substitution reactions. (a) I and III (b) II and IV (c) I, II, and III (d) I, III, and IV
Last Answer : I, II, and III
Description : Which of the following halogen acids is most reactive towards the given reaction ? `R-O-R overset(HX)rarr`
Last Answer : Which of the following halogen acids is most reactive towards the given reaction ? `R-O-R overset(HX)rarr` A. HCl B. HI C. HBr D. Equally reactive
Description : Assertion (A): Ethyl alcohol is soluble in organic solvents Reason(R): Calcium chloride can form an addition compound with ethyl alcohol
Last Answer : Assertion (A): Ethyl alcohol is soluble in organic solvents Reason(R): Calcium chloride can form an addition ... is false D. A is false but R is true
Description : Statement I: In strongly acidic solutions , anline becomes more reactive towards electrophilic reagents Statement II: The amino group being completely
Last Answer : Statement I: In strongly acidic solutions , anline becomes more reactive towards electrophilic reagents ... Assertion is false but Reason is true.
Description : Identify the group in which all the polymers mentioned can be used to make fibres. (A) Butadiene copolymers, Polyamides, Urea-formaldehyde (B) Cellulose derivatives, Polyisoprene, Polyethylene (C) Cellulose derivatives, Polyamides, Polyurethane (D) Polypropylene, Poly vinyl chloride, Silicon
Last Answer : (B) Cellulose derivatives, Polyisoprene, Polyethylene
Description : Arrange the following carboxyl compounds in increasing order of their reactivity in nucleophilic addition reactions. Explain with proper reasoning : Benzaldehyde. p-tolualdeyde, p-nitrobenzaldehyde, Acetophenone.
Last Answer : Ans. Acetophenone is a ketone while all others are aldehydes, therefore it is least reactive. In p-tolualdehyde, there is methyl group (CH3 ) at para position w.r.t. to the ... overall order of increasing reactivity : acetophenone < p-tolualdehyde < benzaldehyde < p-nitrobenzaldehyde.
Description : For reactions of ethylbenzene, the ethyl group is considered : (a) ortho director (b) ortho-para director (c) meta director (d) ortho-meta director
Last Answer : ortho-para director
Description : During the reaction of Benzene diazonium chloride with para-cresol the substitution occurs at_____position of p-cresol.
Last Answer : During the reaction of Benzene diazonium chloride with para-cresol the substitution occurs at_____position of p-cresol.
Description : What purpose does FeCl3 serve in the electrophilic aromatic substitution reaction between chlorine and benzene? (a) It serves as a radical initiator to produce the chlorine radical needed to propagate the ... by reacting with the Cl2 and thereby activates it toward attack by benzene's π electrons.
Last Answer : It serves as a Lewis acid catalyst by reacting with the Cl2 and thereby activates it toward attack by benzene’s π electrons.
Description : Arrange the following compound in reactivity towards EAS (Electrophilic aromatic substitution) reaction ?
Last Answer : Arrange the following compound in reactivity towards EAS (Electrophilic aromatic substitution) reaction ? A. `A gt B gt ... A` D. `C gt B gt D gt A`
Description : Among the following compounds, the decreasing order of reactivity towards electrophilic substitution is :
Last Answer : Among the following compounds, the decreasing order of reactivity towards electrophilic substitution is : ... C. `IVgtIgtIIgtIII` D. `IIIgtIgtIIgtIV`
Description : Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds:
Last Answer : Identify the correct order of reactivity in electrophilic substitution reactions of the following ... C. `IIgtIgtIIIgtIV` D. `IIgtIIIgtIgtIV`
Description : Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds :
Last Answer : Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds : ... ` C. `2gt1gt3gt4` D. `2gt3gt1gt4`
Description : Give reason: Alkanes undergo only substitution reactions but alkenes and alkynes undergo both substitution and addition reactions.
Last Answer : Alkenes and alkynes have double and triple bonds, which on breaking can add hydrogen atoms to satisfy the valency.
Description : Anthracene undergoes electrophilic substitution reactions mainly at (a) C-1 (b) C-2 (c) C-9 (d) C-1 and C-2
Last Answer : C-9
Description : Which of the following compounds reacts least rapidly in electrophilic substitution reactions? (a) Nitrobenzene (b) Phenol (c) Bromobenzene (d) Toluene
Last Answer : Nitrobenzene
Description : In electrophilic aromatic substitution reactions a chlorine substituent __________. (a) is a deactivator and a m-director (b) is a deactivator and an o,p-director (c) is an activator and a m-director (d) is an activator and an o,p-director
Last Answer : is a deactivator and an o,p-director
Description : An organic compound (A) has a molecular weight 78 and an empirical formula CH. (A) is resistant to attack by oxidizing agents but undergoes substitution and addition reactions. X-ray analysis shows that the ... suggests that compound (A) is (a) Benzene (b) Cyclohexane (c) Toluene (d) n-Hexane
Last Answer : Benzene