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प्रश्न
Which would undergo SN2 reaction faster in the following pair and why ?
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उत्तर
Primary alkyl halides prefer to undergo SN2 reactions than tertiary alkyl halides because of less steric hindrance experienced by the approaching nucleophile. Hence, out of the given pair (CH3−CH2−Br) would undergo SN2 reaction faster.
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संबंधित प्रश्न
Write the major products(s) in the following:
What are ambident nucleophiles? Explain with an example.
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
In the SN1 reaction, racemization takes place. It is due to:
The order of reactivities of the following alkyl halides for an SN2 reaction is:
How do polar solvents help in the first step in SN1 mechanism?
Retention of configuration is observed in ______.
The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
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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
Which one of the following chlorohydrocarbons readily undergoes solvolysis?
