Advertisements
Advertisements
Question
Out of C6H5CH2Cl and C6H5CHClC6H5, which is more easily hydrolysed by aqueous KOH.
Advertisements
Solution
C6H5CHClC6H5 is hydrolysed faster.
- The hydrolysis of an alkyl halide is a nucleophilic substitution reaction. For aryl halides, this occurs through the SN1 method, resulting in carbocation.
- C6H5CH2Cl or benzyl chloride gives
carbocation while C6H5CHClC6H5 generates 
. - Out of I and II, carbocation II is more stable. Two attached phenyl rings on the carbon carry the positive charge.
- This leads to increased delocalisation of the positive charge and greater carbocation stability. This leads to faster formation of (II) and easier hydrolysis of the resulting halide than benzyl chloride.
APPEARS IN
RELATED QUESTIONS
Discuss the mechanism of alkaline hydrolysis of bromomethane.
What are ambident nucleophiles? Explain with an example.
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
Write the mechanism of the following reaction:
\[\ce{{n}BuBr + KCN ->[EtOH-H2O] {n}BuCN}\]
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.
In the SN1 reaction, racemization takes place. It is due to:
SN2 mechanism proceeds through intervention of ____________.
An important chemical method to resolve a racemic mixture makes use of the formation of ______.
Among the following, the dissociation constant is highest for:
Which of the following compounds will give a racemic mixture on nucleophilic substitution by OH ion?
1-Bromoethane, 1-Bromopropane, 1-Bromobutane, Bromobenzene
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?
\[\ce{CH3CH2CH2CH3 -> CH3CH2CH2CH2Cl + CH3CH2CHClCH3}\]
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) |
Why are aryl halides less reactive towards nucleophilic substitution reactions than alkyl halides?
Give reason for the following:
The product formed during SN1 reaction is a racemic mixture.
Give the mechanism of the following reaction:
\[\ce{CH3CH2OH ->[H2SO4][413 K] CH3CH2-O-CH2CH3 + H2O}\]
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:
Which of the following reactions is an example of nucleophilic substitution reaction?
