Advertisements
Advertisements
प्रश्न
What is the action of the following on ethyl bromide
alcoholic solution of potassium hydroxide.
Advertisements
उत्तर
\[\ce{\underset{\text{ethylbromide}}{C2H5Br} + alc KOH ->\underset{\text{ethene}}{CH2} = CH2 + KBr + H2O}\]
APPEARS IN
संबंधित प्रश्न
Which would undergo SN1 reaction faster in the following pair and why?
Which would undergo SN2 reaction faster in the following pair and why ?
Which alkyl halide from the following pair would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
CH3CH2CH2CH2Br or \[\begin{array}{cc}
\ce{CH3CH2CHCH3}\\
\phantom{.....}|\\
\phantom{.......}\ce{Br}\
\end{array}\]
Which compound in the following pair will react faster in SN2 reaction with OH−?
CH3Br or CH3I
Which compound in the following pair will react faster in SN2 reaction with OH−?
(CH3)3CCl or CH3Cl
Arrange the compounds of the following set in order of reactivity towards SN2 displacement:
1-Bromobutane, 1-Bromo-2, 2-dimethylpropane, 1-Bromo-2-methylbutane, 1-Bromo-3-methylbutane
Out of C6H5CH2Cl and C6H5CHClC6H5, which is more easily hydrolysed by aqueous KOH.
SN1 reactions are accompanied by racemization in optically active alkyl halides.
Given reasons: SN1 reactions are accompanied by racemization in optically active alkyl halides.
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.
In the SN1 reaction, racemization takes place. It is due to:
Which among MeX, RCH2X, R2CHX and R3CX is most reactive towards SN2 reaction?
Isopropyl chloride undergoes hydrolysis by:
Which of the following is an optically active compound?
The process of separation of a racemic modification into d and l-enantiomers is called ____________.
Which of the following is a chiral compound?
The correct order of increasing the reactivity of C–X bond towards nucleophile in following compounds.
(I)
(II)
(CH3)3CCl
(III)
(CH3)2CHCl
(IV)
The reaction of C6H5–CH=CH–CH3 with HBr produces:
Complete the following analogy:
Same molecular formula but different structures: A : : Non superimposable mirror images: B
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 \[\ce{FeCl3}\].
Elimination reactions (especially β-elimination) are as common as the nucleophilic substitution reaction in case of alkyl halides. Specify the reagents used in both cases.
Chlorination of alkanes is an example of
Which of the following is the definition of chirality?
CCl4 is insoluble in water because:-
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 ______ %.
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
The correct order of increasing reactivity of
C-X bond towards nucleophile in the following compounds is:
