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प्रश्न
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
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उत्तर
\[\begin{array}{cc}
\ce{CH3 - CH - CH2CH3 + NaOH ->[H2O][Hydrolysis] CH3 - CH - CH2CH3 + NaBr + H2O}\\
|\phantom{................................................................}|\phantom{..................................}\\
\ce{\underset{2-Bromobutane}{Br}}\phantom{...................................................}\ce{\underset{Butan-2-ol}{OH}}\phantom{...................................}
\end{array}\]
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संबंधित प्रश्न
Out of 
, which is more reactive towards SN1 reaction and why?
Write the structures of A, B and C in the following:
In the following pair of halogen compounds, which compound undergoes a faster SN1 reaction?
Arrange the compounds of the following set in order of reactivity towards SN2 displacement:
1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3-methylbutane
How the following conversion can be carried out?
Ethyl chloride to propanoic acid.
Halogenation of alkanes is ____________.
Which one is most reactive towards SN1 reaction?
Most reactive halide towards SN1 reaction is ____________.
Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of ____________.
Racemic compound has ____________.
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 \[\ce{FeCl3}\].
The major product formed in the following reaction is:
The number of chiral carbons present in the molecule given below is ______.
Optical activity of an enantiomeric mixture is +12.6° and the specific rotation of (+) isomer is +30°. The optical purity is ______ %.
Assertion (A) : Nucleophilic substitution of iodoethane is easier than chloroethane.
Reason (R) : Bond enthalpy of C-I bond is less than that of C-Cl bond.
Inversion of configuration occurs 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
Acetic anhydride from acetic acid
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 \[\begin{array}{cc}\phantom{.......}\ce{CH3}\\
\phantom{...}|\\
\ce{H3C - C - Br}\\
\phantom{...}|\\
\phantom{.......}\ce{CH3}\\
\end{array}\]
Consider the reactions,
(i) \[\begin{array}{cc}
\phantom{}\ce{\underset{}{(CH3)2CH - CH2Br} ->[C2H5OH] \underset{}{(CH3)2CH - CH2OC2H5 + HBr}}\\
\end{array}\]
(ii) \[\begin{array}{cc}
\phantom{}\ce{\underset{}{(CH3)2CH - CH2Br} ->[C2H5O-] \underset{}{(CH3)2CH - CH2OC2H5 + Br-}}\\
\end{array}\]
The mechanisms of reactions (i) and (ii) are respectively:
