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प्रश्न
Identify 'A' in the following reaction -
(a) 2- Bromo-2 methylbutane
(b) 1 -Bromo-2,2-dimethylpropane
(c) 1 - Bromo - 3 -methylbutane
(d) 1 - Bromo- 2 -methylpropane
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उत्तर
1 -Bromo-2,2-dimethylpropane
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संबंधित प्रश्न
Write the structure of an isomer of compound C4H9Br which is most reactive towards SN1 reaction
Which would undergo SN1 reaction faster in the following pair and why?
How do you convert the following:
Ethanol to propanenitrile
Which would undergo SN2 reaction faster in the following pair and why ?
Write the structures of A, B and C in the following:
What are ambident nucleophiles? Explain with an example.
Arrange the compounds of the following set in order of reactivity towards SN2 displacement:
2-Bromo-2-methylbutane, 1-Bromopentane, 2-Bromopentane
The treatment of alkyl chlorides with aqueous KOH leads to the formation of alcohols but in the presence of alcoholic KOH, alkenes are major products. Explain.
What is the action of the following on ethyl bromide
alcoholic solution of potassium hydroxide.
What is the action of the following on ethyl bromide?
silver acetate
Answer the following question.
Write one stereochemical difference between SN1 and SN2 reactions.
Which of the following is a primary halide?
Most reactive halide towards SN1 reaction is ____________.
Optically active isomers but not mirror images are called ____________.
SN2 mechanism proceeds through intervention of ____________.
The process of separation of a racemic modification into d and l-enantiomers is called ____________.
An organic molecule necessarily shows optical activity if it ____________.
Write the structures and names of the compounds formed when compound ‘A’ with molecular formula, \[\ce{C7H8}\] is treated with \[\ce{Cl2}\] in the presence of \[\ce{FeCl3}\].
Match the reactions given in Column I with the types of reactions given in Column II.
| Column I | Column II | |
| (i) |  |
(a) Nucleophilic aromatic substitution |
| (ii) | \[\begin{array}{cc} \ce{CH3 - CH = CH2 + HBr -> CH3 - CH - CH3}\\ \phantom{............................}|\phantom{}\\ \phantom{.............................}\ce{Br}\phantom{} \end{array}\] |
(b) Electrophilic aromatic substitution |
| (iii) |  |
(c) Saytzeff elimination |
| (iv) |  |
(d) Electrophilic addition |
| (v) | \[\begin{array}{cc} \ce{CH3 CH2 CH CH3 ->[alc.KOH] CH3 CH = CH CH3}\\ \phantom{}|\phantom{..........................}\\ \phantom{}\ce{Br}\phantom{........................} \end{array}\] |
(e) Nucleophilic substitution (SN1) |
Which of the following is the definition of chirality?
When CH3CH2CHCl2 is treated NaNH2 product formed is:-
Which one of the following compounds is more reactive towards SN1 reaction?
The major product formed in the following reaction is:
Arrange the following compounds in increasing order of reactivity towards SN2 reaction.
2-Bromopentane, 1-Bromopentane, 2-Bromo-2-methylbutane
Give the mechanism of the following reaction:
\[\ce{CH3CH2OH ->[H2SO4][413 K] CH3CH2-O-CH2CH3 + H2O}\]
The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
|
Nucleophilic Substitution: Influences of solvent polarity: The reaction rate (SN2) of 2-bromopropane and NaOH in ethanol containing 40% water is twice slower than in absolute ethanol. Hence the level of solvent polarity has an influence on both SN1 and SN2 reactions but with different results. Generally speaking, a weak polar solvent is favourable for SN2 reaction, while a strong polar solvent is favourable for SN1. Generally speaking, the substitution reaction of tertiary haloalkane is based on SN1 mechanism in solvents with a strong polarity (for example ethanol containing water). |
Answer the following questions:
(a) Why racemisation occurs in SN1? (1)
(b) Why is ethanol less polar than water? (1)
(c) Which one of, the following in each pair is more reactive towards SN2 reaction? (2)
(i) CH3 – CH2 – I or CH3CH2 – Cl
(ii)
OR
(c) Arrange the following in the increasing order of their reactivity towards SN1 reactions: (2)
(i) 2-Bromo-2-methylbutane, 1-Bromo-pentane, 2-Bromo-pentane
(ii) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3- methylbutane
Discuss the mechanism of alkaline hydrolysis of methyl bromide.
Which alkyl halide from the following pair would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
\[\begin{array}{cc}\ce{CH3CHCH2CH2Br}\\|\phantom{.........}\\\ce{CH3}\phantom{......}\end{array}\] or \[\begin{array}{cc}\ce{CH3CH2CHCH2Br}\\\phantom{}|\\\phantom{...}\ce{CH3}\end{array}\]
