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प्रश्न
Retention of configuration is observed in ______.
विकल्प
SN1 reaction
SN2 reaction
Neither SN1 nor SN2 reaction
SN2 reaction as well as SN1 reaction
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उत्तर
Retention of configuration is observed in SN1 reaction.
Explanation:
Both retention and inverted products are generated in SN1 reactions, but only the inverted product is formed in SN2 reactions.
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संबंधित प्रश्न
Write the structure of an isomer of compound C4H9Br which is most reactive towards SN1 reaction
How do you convert the following:
Ethanol to propanenitrile
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
Which of the following is an optically active compound?
Which of the following compounds will give a racemic mixture on nucleophilic substitution by OH ion?
1-Bromoethane, 1-Bromopropane, 1-Bromobutane, Bromobenzene
Which of the compounds will react faster in SN1 reaction with the –OH ion?
\[\ce{CH3-CH2-Cl}\] or \[\ce{C6H5-CH2-Cl}\]
How do polar solvents help in the first step in SN1 mechanism?
The decreasing order of reactivity of the following compounds towards nucleophilic substitution (SN2) 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
