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प्रश्न
In which reaction mechanism carbocation is formed?
पर्याय
SN1
SN2
Both SN1 and SN2
None of them
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उत्तर
SN1
APPEARS IN
संबंधित प्रश्न
Write the structure of the major product in each of the following reaction :
Which compound in the following pair will react faster in SN2 reaction with OH−?
CH3Br or CH3I
Out of C6H5CH2Cl and C6H5CHClC6H5, which is more easily hydrolysed by aqueous KOH.
What happens when chlorobenzene is subjected to hydrolysis?
Which would undergo SN2 reaction faster in the following pair and why ?
CH3 – CH2 – Br and CH3 – CH2 – I
What is the action of the following on ethyl bromide?
moist silver oxide
Answer the following question.
Write one stereochemical difference between SN1 and SN2 reactions.
Which compound in the following pair reacts faster in SN2 reaction with OH–?
- CH3Br or CH3
- CH3Cl, (CH3)3CCl
Which of the following is a primary halide?
Which of the following reactions is an example of nucleophilic substitution reaction?
Which one is most reactive towards SN1 reaction?
SN2 mechanism proceeds through intervention of ____________.
Isopropyl chloride undergoes hydrolysis by:
An important chemical method to resolve a racemic mixture makes use of the formation of ______.
Which of the following compound will undergo racemisation when reacts with aq. KOH?
(i)
(ii)
CH3CH2CH2Cl
(iii)
\[\begin{array}{cc}
\ce{CH3}\phantom{..}\\
|\phantom{....}\\
\ce{CH3-CH-CH2Cl}
\end{array}\]
(iv)
\[\begin{array}{cc}
\phantom{..}\ce{H}\\
\phantom{..}|\\
\ce{CH3-C-Cl}\\
\phantom{..}|\\
\phantom{.....}\ce{C2H5}
\end{array}\]
The reaction of C6H5–CH=CH–CH3 with HBr produces:
Which of the following alkyl halides will undergo SN1 reaction most readily?
Complete the following analogy:
Same molecular formula but different structures: A : : Non superimposable mirror images: B
Which reagent will you use for the following reaction?
\[\ce{CH3CH2CH2CH3 -> CH3CH2CH2CH2Cl + CH3CH2CHClCH3}\]
Which of the compounds will react faster in SN1 reaction with the –OH ion?
\[\ce{CH3-CH2-Cl}\] or \[\ce{C6H5-CH2-Cl}\]
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 \[\ce{FeCl3}\].
Why are aryl halides less reactive towards nucleophilic substitution reactions than alkyl halides?
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
Retention of configuration is observed in ______.
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
An organic compound A with the molecular formula (+) C4H9Br undergoes hydrolysis to form (+) C4H9OH. Give the structure of A and write the mechanism of the reaction.
Explain why Grignard reagents should be prepared under anhydrous conditions.
Which alkyl halide from the following pair would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
\[\begin{array}{cc}\ce{CH3CH2CHCH3}\\\phantom{...}|\\\phantom{....}\ce{Br}\end{array}\] or \[\begin{array}{cc}\phantom{.....}\ce{CH3}\\\phantom{..}|\\\ce{H3C - C - Br}\\\phantom{..}|\\\phantom{....}\ce{CH3}\end{array}\]
