Advertisements
Advertisements
प्रश्न
In which reaction mechanism carbocation is formed?
विकल्प
SN1
SN2
Both SN1 and SN2
None of them
Advertisements
उत्तर
SN1
APPEARS IN
संबंधित प्रश्न
Write the structure of an isomer of compound C4H9Br which is most reactive towards SN1 reaction
Write the main products when methyl chloride is treated with AgCN.
Given reasons: C–Cl bond length in chlorobenzene is shorter than C–Cl bond length in CH3–Cl.
Which alkyl halide from the following pair would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
CH3CH2CH2CH2Br or \[\begin{array}{cc}
\ce{CH3CH2CHCH3}\\
\phantom{.....}|\\
\phantom{.......}\ce{Br}\
\end{array}\]
In the following pair of halogen compounds, which compound undergoes a faster SN1 reaction?
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH2CH2OH + SOCl2 ->}\]
How the following conversion can be carried out?
Ethyl chloride to propanoic acid.
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
alcoholic solution of potassium hydroxide.
What is the action of the following on ethyl bromide:
moist silver oxide
AgCN reacts with haloalkanes to form isocyanide. Haloalkanes react with KCN to form alkyl cyanides as the main product. Why?
The order of reactivity of the given haloalkanes towards nucleophile is:
SN2 mechanism proceeds through intervention of ____________.
An important chemical method to resolve a racemic mixture makes use of the formation of ______.
The process of separation of a racemic modification into d and l-enantiomers is called ____________.
Identify the end product (C) in the following sequence:
\[\ce{C2H5OH ->[SOCl2][Pyridine] A ->[KCN {(alc.)}] B ->[2H2O/H^+] C}\]
Identify X and Y in the following sequence:
\[\ce{C2H5Br ->[X] Product ->[Y] C3H7NH2}\]
Assertion: KCN reacts with methyl chloride to give methyl isocyanide.
Reason: CN– is an ambident nucleophile.
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.
Why are aryl halides less reactive towards nucleophilic substitution reactions than alkyl halides?
Chlorination of alkanes is an example of
Which of the following is the definition of chirality?
Among the following compounds I - IV, which one forms a yellow precipitate on reacting sequentially with (i) NaOH (ii) dil. HNO3 (iii) AgNO3?
 |
 |
 |
 |
| I | II | III | IV |
In SN1 reactions, the correct order of reactivity for the following compounds:
CH3Cl, CH3CH2Cl, (CH3)2CHCl and (CH3)3CCl is ______.
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
Identify the product in the following reaction: 
Which of the following reactions is an example of nucleophilic substitution reaction?
