The electrophile. E attacks the benzene ring to generate the intermediate σ- complex. Of the following which σ- complex is of lowest energy?

1. 

2. 

3. 

4. 

Subtopic:  Directive Effect of functional grp |
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NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Consider the following bromides:

the correct order of SN1 reactivity is:

1. A>B>C

2. B>C>A

3. B>A>C

4. C>B>A

Subtopic:  SN1 & SN2 Reactions |
 74%
From NCERT
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Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

KI in acetone, undergoes SN2 reaction with each of P, Q, R and S, the rates of the reaction vary as:

Answer to question: KI in acetone, undergoes SN2 reaction with

1. P > Q > R > S

2. S > P > R > Q

3. P > R > Q > S

4. R > P > S > Q

Subtopic:  SN1 & SN2 Reactions |
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Hints

In an SN1 reaction on chiral centres there is

1. 100% racemisation

2. inversion more than retention leading to partial racemisation

3. 100% retention

4. 100% inversion

Subtopic:  SN1 & SN2 Reactions |
 60%
NEET - 2015
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Hints

If X is halogen the correct order for SN2 reactivity is-

1. R2CHX > R3CX > RCH2X

2. RCH2X > R3CX > R2CHX

3. RCH2X > R2CHX > R3X

4. R3CX > R2CHX > RCH2X

Subtopic:  SN1 & SN2 Reactions |
 80%
From NCERT
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To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The compound which reacts with HBr obeying Markownikoff's rule is:

1. CH2=CH2   

2. 

3. 

4. 

Subtopic:  Addition Reaction of C=C |
 61%
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Hints

The formation of cyanohydrin from a ketone is an example of:

(1) electrophilic addition

(2) nucleophilic addition

(3) nucleophilic substitution

(4) electrophilic substitution

Subtopic:  Addition Reaction of C=N, C=0 |
 69%
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Hints

Which of the following is an example of the elimination reaction?

(1) Chlorination of methane

(2) dehydration of ethanol

(3) nitration of benzene

(4) hydroxylation of ethylene

 

Subtopic:  Reaction Intermediates |
 84%
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Hints

The SN2 mechanism for R-X + KOH (aq)  R-OH + KX follows with:

(1) 100% inversion

(2) 50% inversion

(3) 40% inversion

(4) 30% inversion

Subtopic:  SN1 & SN2 Reactions |
 74%
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Hints

The elimination reaction among the following is:

1. CH3CH3+Cl2CH3CH2Cl+ HCl

2. CH3Cl+ KOH(aq.) CH3OH +KCl

3. CH2=CH2 +Br2 CH2BrCH2Br

4. C2H5Br+ KOH(alc.) C2H4 + KBr+H2O

Subtopic:  Reaction Intermediates |
 81%
From NCERT
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NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh