Explain why nucleophilic substitution reactions are not very common in phenols.

Explain why nucleophilic substitution reactions are not very common in phenols.
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Explain why nucleophilic substitution reactions are not very common in phenols.
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(A) Ethyl chloride is more reactive than vinyl chloride towards nucleophilic substitution reactions. (R) Vinyl chloride is `+I` electron pushing group

Description : (A) Ethyl chloride is more reactive than vinyl chloride towards nucleophilic substitution reactions. (R) Vinyl chloride is `+I` electron pushing group

Last Answer : (A) Ethyl chloride is more reactive than vinyl chloride towards nucleophilic substitution reactions. (R) Vinyl ... A) is incorrect but (R) is correct.

Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

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.

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

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

Esters and amides are most easily made by nucleophilic acyl substitution reactions on : (a) acid anhydrides (b) carboxylates (c) carboxylic acids (d) acid chlorides

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

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) Aldehydes are more sterically hindered than esters. (c) Once the nucleophile adds to an aldehyde, the tetrahedral intermediate is too sterically hindered to eliminate one of the attached groups. (d) Once the nucleophile adds to an aldehyde, neither H− nor R− can be eliminated since they are strongly basic

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

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

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

Alkyl halides undergo (a) Electrophilic substitution reactions (b) Electrophilic addition reactions (c) Nucleophilic substitution reactions (d) Nucleophilic addition reactions

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

Phenols do not undergo substitution of the — OH group like alcohols. Explain.

Description : Phenols do not undergo substitution of the — OH group like alcohols. Explain.

Last Answer : The C — O bond in phenols has some double bond character due to resonance and hence cannot be easily cleaved by a nucleophile. In contrast, the C — O bond in alcohols is a pure single bond and hence can be easily cleaved by a nucleo phile.

Which of the following can undergo nucleophilic substitution under ordinary conditions? I Allyl chloride II Benzyl chloride III n-Propyl chloride IV V

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

Which of the following undergoes nucleophilic substitution exclusively by `S_(N^(1))` mechanism?

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

Which one of the following is most reactive towards nucleophilic substitution reaction ?

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)`

Which of the following is least reactive in a nucleophilic substitution reaction?

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`

Quinoline undergoes nucleophilic substitution on heating with NaNH2 to give (a) 2-Aminoquinoline (b) 4-Aminoquinoline (c) 3-Aminoquinoline (d) 8-Aminoquinoline

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

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

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

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

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

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

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

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 more sterically hindered than the ester (c) the methoxide is a better leaving group than chloride (d) chloride is a better leaving group than methoxide

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

The characteristic reaction of carboxylic acids is : (a) electrophilic addition (b) electrophilic substitution (c) nucleophilic addition (d) nucleophilic 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

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

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

Which alkyl halides react most readily by nucleophilic substitution? (a) CH3CH2Cl (b) CH3CH2I (c) CH3CH2Br (d) CH3CH2F

Description : Which alkyl halides react most readily by nucleophilic substitution? (a) CH3CH2Cl (b) CH3CH2I (c) CH3CH2Br (d) CH3CH2F

Last Answer : CH3CH2I

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

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

Ethylene is obtained from ethyl bromide by : (a) Simple heating (b) Hydrolysis (c) Dehydrohalogenation (d) Nucleophilic substitution

Description : Ethylene is obtained from ethyl bromide by : (a) Simple heating (b) Hydrolysis (c) Dehydrohalogenation (d) Nucleophilic substitution

Last Answer : Dehydrohalogenation

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

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

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.

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. 

Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds:

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`

Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds :

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`

Give reason: Alkanes undergo only substitution reactions but alkenes and alkynes undergo both substitution and addition reactions.

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.

Anthracene undergoes electrophilic substitution reactions mainly at (a) C-1 (b) C-2 (c) C-9 (d) C-1 and C-2

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

Which of the following compounds reacts least rapidly in electrophilic substitution reactions? (a) Nitrobenzene (b) Phenol (c) Bromobenzene (d) Toluene

Description : Which of the following compounds reacts least rapidly in electrophilic substitution reactions? (a) Nitrobenzene (b) Phenol (c) Bromobenzene (d) Toluene

Last Answer : Nitrobenzene

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

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

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

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

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 distance between adjacent carbon atoms is 1.39Å (intermediate between single and double bond lengths). The evidence suggests that compound (A) is (a) Benzene (b) Cyclohexane (c) Toluene (d) n-Hexane

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

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 distance between adjacent carbon atoms is 1.39Å (intermediate between single and double bond lengths). The evidence suggests that compound (A) is (a) Benzene (b) Cyclohexane (c) Toluene (d) n-Hexane

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

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

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

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 sp3 hybridized carbon undergo substitution and elimination reactions. (c) The electronegative atom is replaced by another atom or group in substitution reactions. (d) (a) and (b)

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)

Assertion : Phenols are more acidic than aliphatic alcohols. Reason : Phenoxides are stabilized by resonance.

Description : Assertion : Phenols are more acidic than aliphatic alcohols. Reason : Phenoxides are stabilized by resonance.

Last Answer : Assertion : Phenols are more acidic than aliphatic alcohols. Reason : Phenoxides are stabilized by resonance. ... D. A is incorrect but R is correct

Phenols does not react with

Description : Phenols does not react with

Last Answer : Phenols does not react with A. sodium bicarbonate B. sodium hydroxide C. potassium hydroxide D. ferric chloride

Assertion (A): Alkyl aryl ethers on reaction with HI give alkyl iodide phenols Reason (R): Aryl - oxygen bond is weaker than alkyl oxygen bond

Description : Assertion (A): Alkyl aryl ethers on reaction with HI give alkyl iodide phenols Reason (R): Aryl - oxygen bond is weaker than alkyl oxygen bond

Last Answer : Assertion (A): Alkyl aryl ethers on reaction with HI give alkyl iodide phenols Reason (R): Aryl - oxygen ... is false D. A is false but R is true

The smell of fat turned rancid is due to (A) Presence of vit E (B) Presence of quinones (C) Phenols (D) Volatile fatty acids

Description : The smell of fat turned rancid is due to (A) Presence of vit E (B) Presence of quinones (C) Phenols (D) Volatile fatty acids

Last Answer : Answer : D

Protein is a polymer of (A) Sugars (B) Phenols (C) Amino acids (D) Carboxylic acids

Description : Protein is a polymer of (A) Sugars (B) Phenols (C) Amino acids (D) Carboxylic acids

Last Answer : Answer : C

Phenols are added in gasoline to (A) Improve the octane number(B) Act as an antioxidant(C) Reduce its viscosity(D) Increase its pour point

Description : Phenols are added in gasoline to (A) Improve the octane number (B) Act as an antioxidant (C) Reduce its viscosity (D) Increase its pour point

Last Answer : (B) Act as an antioxidant

While separating a mixture of ortho and para-nitro phenols by steam distillation, name the isomer which will be steam volatile. Give reasons.

Description : While separating a mixture of ortho and para-nitro phenols by steam distillation, name the isomer which will be steam volatile. Give reasons.

Last Answer : In o-nitrophenol, there is intramolecular hydrogen bonding as follows : In p-nitrophenol, there is intramolecular hydrogen bonding as follows :   Due to intermolecular H ... -nitrophenol. Hence o-nitraphenol due to its lower b. p. is steam volatile while pnitrophenol is not.

Alcohols are easily protonated than phenols. Justify.

Description : Alcohols are easily protonated than phenols. Justify.

Last Answer : Ans. In phenols lone pair of electrons on the oxygen atom are delocalised over the benzene ring due to resonance and hence are not easily available for protonation. In contrast in alcohols, ... oxygen atom are localized due to absence of resonance and hence are easily available for protonation. 

Phenol has smaller dipole moment than methanol. (OR) Why are dipole moments of phenols smaller than dipole moments of alcohols ?

Description : Phenol has smaller dipole moment than methanol. (OR) Why are dipole moments of phenols smaller than dipole moments of alcohols ?

Last Answer : Due to electron-withdrawing effect of the benzene ring, the C — O bond in phenol is less polar but in case of methanol due to electron-donating effect of — CH3 group, C — O bond is more polar.

Phenols can be easily distinguished from alcohols because (a) phenols are soluble in NaOH, but alcohols are not (b) alcohols are soluble in NaOH, but phenols are not (c) phenols are soluble in NaHCO3, but alcohols are not (d) alcohols are soluble in NaHCO3, but phenols are not

Description : Phenols can be easily distinguished from alcohols because (a) phenols are soluble in NaOH, but alcohols are not (b) alcohols are soluble in NaOH, but phenols are not (c) phenols are soluble in NaHCO3, but alcohols are not (d) alcohols are soluble in NaHCO3, but phenols are not

Last Answer : phenols are soluble in NaOH, but alcohols are not

Which group forms the strongest H-bonds to water molecules? (a) Alcohols (b) Ethers (c) Phenols (d) All equally strong

Description : Which group forms the strongest H-bonds to water molecules? (a) Alcohols (b) Ethers (c) Phenols (d) All equally strong

Last Answer : Phenols

Which one of the following compounds form zwitterions?(a) carbonyl compounds (b) amino acids (c) phenols (d) heterocyclic compounds

Description : Which one of the following compounds form zwitterions? (a) carbonyl compounds (b) amino acids (c) phenols (d) heterocyclic compounds

Last Answer : amino acids

Arrange the following compounds in decreasing order of nucleophilic addition with semicarbazide `NH_(2)NHCONH_(2)` i.e., `ddot(N)H_(2)-ddot(Z)`

Description : Arrange the following compounds in decreasing order of nucleophilic addition with semicarbazide `NH_(2)NHCONH_(2)` i.e., `ddot(N)H_(2)-ddot(Z)`

Last Answer : Arrange the following compounds in decreasing order of nucleophilic addition with semicarbazide `NH_(2)NHCONH_(2)` i.e., `ddot(N)H_(2)-ddot(Z)`

Arrange the following compounds in decreasing order of nucleophilic addition with semicarbazide `NH_(2)NHCONH_(2)` i.e., `ddot(N)H_(2)-ddot(Z)`

Description : Arrange the following compounds in decreasing order of nucleophilic addition with semicarbazide `NH_(2)NHCONH_(2)` i.e., `ddot(N)H_(2)-ddot(Z)`

Last Answer : Arrange the following compounds in decreasing order of nucleophilic addition with semicarbazide `NH_(2)NHCONH_(2)` i.e., `ddot(N)H_(2)-ddot(Z)`

Which of the following is an example of nucleophilic addition of acetone?

Description : Which of the following is an example of nucleophilic addition of acetone?

Last Answer : Which of the following is an example of nucleophilic addition of acetone? A. Ketal formation B ... gas C. Cyanohydrin formation D. Bisulphite additon