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प्रश्न
What is dehydrohalogenation? State the rule for the formation of the preferred product of dehydrohalogenation.
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उत्तर
- Dehydrohalogenation reaction: When an alkyl halide having at least one β-hydrogen is boiled with an alcoholic solution of potassium hydroxide (KOH), it undergoes elimination of hydrogen atom from β-carbon and halogen atom from α-carbon resulting in the formation of an alkene. As hydrogen and halogen are removed in this reaction, it is termed a dehydrohalogenation reaction.
- Saytzeff’s rule:
Statement - “In dehydrohalogenation reaction, the preferred product is that alkene which has a greater number of alkyl groups attached to doubly bonded carbon atoms.”
संबंधित प्रश्न
from the following pair would undergo SN2 faster from the other?
a. CH3CH2CH2I b. CH3CH2CH2Cl
Complete the following reaction giving major product.
\[\begin{array}{cc}\ce{CH3\phantom{................}}\\
|\phantom{...................}\\
\ce{CH3 - C - CH2 - Cl ->[Na/dry ether] A}\\
|\phantom{...................}\\
\ce{CH3\phantom{................}}
\end{array}\]
Give reasons:
Haloarenes are less reactive than haloalkanes.
Convert the following:
Ethanol to propane nitrile
HCl is added to a hydrocarbon ‘A’ \[\ce{(C4H8)}\] to give a compound ‘B’ which on hydrolysis with aqueous alkali forms tertiary alcohol ‘C’ \[\ce{(C4H10O)}\]. Identify ‘A’ ,‘B’ and ‘C’.
Complete the following reaction sequence by writing the structural formulae of the organic compound 'A', 'B' and 'C'.
\[\ce{Isopropyl alcohol ->[\triangle][PBr3] A ->[][NH3 excess] B}\]
Propane nitrile can be prepared by heating ____________
The following will react faster by SN1 mechanism
Write the correct order of increasing ease of dehydrohalogenation.
\[\ce{\underset{\text{(I)}}{CH3 - CH2 - CH2 - Cl}}\]
\[\ce{\underset{\text{(II)}}{CH3 - CH(Cl) - CH3}}\]
\[\begin{array}{cc}
\ce{CH3}\\
|\\
\ce{CH3-C-Cl}\phantom{...}\\
|\\
\ce{CH3}\\
\ce{(III)}
\end{array}\]
Explain the factors affecting SN1 and SN2 mechanism.
Ethyl bromide undergoes the following reaction:
\[\ce{\underset{Ethyl bromide}{C2H5Br} + \underset{(aq.)}{KOH} ->[\Delta] \underset{Ethyl alcohol}{C2H5OH} + KBr}\]
Which of the following is a WRONG statement?
Dehydrohalogenation of an alkyl halide is ____________.
Nitroalkanes are obtained in laboratory from primary or secondary alkyl halides by the action of ______.
What type of hybridisation is present in carbocation formed during the alkaline hydrolysis of 1- bromo-1- phenyl ethane?
When C2H5Br is treated with excess of alc. NH3, the major product obtained is ____________.
The major product formed when 2-bromobutane is treated with alcoholic KOH is ______.
Which of the following statements is incorrect regarding the dehydrohalogenation of alkenes?
Observe the following and answer the questions given below:
Name the type of halogen derivative.
Observe the following and answer the question given below:
Comment on the bond length of C-X bond in it.
Observe the following and answer the question given below:
Can react by SN1 mechanism? Justify your answer.
Complete the following reactions giving major product.
\[\begin{array}{cc}
\ce{CH3}\phantom{................}\\
|\phantom{...................}\\
\ce{CH3 - C - CH2 - Cl ->[Na/dry ether] A}\\
|\phantom{...................}\\
\ce{CH3}\phantom{.................}
\end{array}\]
Complete the following reaction giving major product.
\[\begin{array}{cc}
\ce{CH3}\phantom{...............}\\
|\phantom{..................}\\
\ce{CH3 - C - CH2 - Cl->[Na/dry ether]A}\\
|\phantom{..................}\\
\ce{CH3}\phantom{...............}\\
\end{array}\]
Complete the reaction:
\[\ce{CH3CH2Cl ->[AgCN][alc.\Delta]}\] ?
Identify the chiral molecule from the following.
Complete the following reaction giving major product.
\[\begin{array}{cc}
\ce{CH3}\phantom{................}\\
|\phantom{..................}\\
\ce{CH3 - C - CH2 - Cl ->[Na/dry ether]A}\\
|\phantom{..................}\\
\ce{CH3}\phantom{................}
\end{array}\]
Complete the following reaction giving major product.
\[\begin{array}{cc}
\ce{CH3}\phantom{................}\\
|\phantom{...................}\\
\ce{CH3 - C - CH2 - Cl->[Na/ dry ether]A}\\
|\phantom{...................}\\
\ce{CH3}\phantom{................}\\
\end{array}\]
Which among the following is NOT benzylic halide?
