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प्रश्न
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 \[\ce{FeCl3}\].
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उत्तर
The compound with molecular formula \[\ce{C7H8}\] is toluene, \[\ce{C6H5CH3}\]. Since \[\ce{^-CH3}\] group is o-, p-directing, therefore, chlorination of toluene gives o-chlorotoluene and p-chlorotoluene, in which the p-isomer predominates.
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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 isomers of the compound having the formula C4H9Br.
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
Arrange the compounds of the following set in order of reactivity towards SN2 displacement:
1-Bromobutane, 1-Bromo-2, 2-dimethylpropane, 1-Bromo-2-methylbutane, 1-Bromo-3-methylbutane
The stability order for carbocation is _______.
(A) 2° > 3° > 1°
(B) 3° > 2° > 1°
(C) 3° > 1° > 2°
(D) 1° > 3° > 2°
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
Halogenation of alkanes is ____________.
Most reactive halide towards SN1 reaction is ____________.
SN2 mechanism proceeds through intervention of ____________.
Which among MeX, RCH2X, R2CHX and R3CX is most reactive towards SN2 reaction?
Which of the following is the correct order of decreasing SN2 reactivity?
Which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism?
The reaction of C6H5–CH=CH–CH3 with HBr produces:
Which of the following statements are correct about this reaction?
(i) The given reaction follows SN2 mechanism.
(ii) (b) and (d) have opposite configuration.
(iii) (b) and (d) have same configuration.
(iv) The given reaction follows SN1 mechanism.
The number of chiral alcohol (s) with molecular formula C4H10O is ______.
Assertion (A) : Nucleophilic substitution of iodoethane is easier than chloroethane.
Reason (R) : Bond enthalpy of C-I bond is less than that of C-Cl bond.
Retention of configuration is observed in ______.
Inversion of configuration occurs 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
Discuss the mechanism of alkaline hydrolysis of methyl bromide.
