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प्रश्न
Identify 'A' in the following reaction -
(a) 2- Bromo-2 methylbutane
(b) 1 -Bromo-2,2-dimethylpropane
(c) 1 - Bromo - 3 -methylbutane
(d) 1 - Bromo- 2 -methylpropane
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उत्तर
1 -Bromo-2,2-dimethylpropane
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संबंधित प्रश्न
Given reasons: C–Cl bond length in chlorobenzene is shorter than C–Cl bond length in CH3–Cl.
Write the structure of the major product in each of the following reaction :
Write the isomers of the compound having the formula C4H9Br.
What are ambident nucleophiles? Explain with an example.
Which compound in the following pair will react faster in SN2 reaction with OH−?
CH3Br or CH3I
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
What happens when chlorobenzene is subjected to hydrolysis?
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?
Which compound in the following pair reacts faster in SN2 reaction with OH–?
- CH3Br or CH3
- CH3Cl, (CH3)3CCl
Which of the following is a primary halide?
Which one of the following halogen compounds is difficult to be hydrolysed by SN1 mechanism?
Optically active isomers but not mirror images are called ____________.
Racemic compound has ____________.
2-Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is ____________.
Which of the following is a chiral compound?
SN1 reaction of alkyl halides lead to ___________.
Which of the following alkyl halides will undergo SN1 reaction most readily?
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 \[\ce{FeCl3}\].
Aryl halides are extremely less reactive towards nucleophilic substitution. Predict and explain the order of reactivity of the following compounds towards nucleophilic substitution:
| (I) |  |
| (II) |  |
| (III) |  |
Which one is the correct order of nucleophilic strength (pKa) of following nucleophiles?
Which of the following compounds will show retention in configuration on nucleophile substitution by OH− ion?
In SN1 reactions, the correct order of reactivity for the following compounds:
CH3Cl, CH3CH2Cl, (CH3)2CHCl and (CH3)3CCl is ______.
Optical activity of an enantiomeric mixture is +12.6° and the specific rotation of (+) isomer is +30°. The optical purity is ______ %.
The decreasing order of reactivity of the following compounds towards nucleophilic substitution (SN2) 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
Identify the product in the following reaction: 
The compound that will undergo SN1 reaction with the fastest rate is:
