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प्रश्न
How the following conversion can be carried out?
Ethyl chloride to propanoic acid
उत्तर
\[\ce{\underset{Ethyl chloride}{CH3CH2Cl} ->[KCN/EtOH-H2O][nucleophilic substitution] \underset{Propanenitrile}{CH3CH2CN} ->[H^+/H2O][hydrolysis] \underset{Propanoic acid}{CH3CH2COOH}}\]
APPEARS IN
संबंधित प्रश्न
Write the main products when methyl chloride is treated with AgCN.
In the following pair of halogen compounds, which compound undergoes a faster SN1 reaction?
How will you bring about the following conversion?
Toluene to benzyl alcohol
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH2CH2OH + SOCl2 ->}\]
Out of C6H5CH2Cl and C6H5CHClC6H5, which is more easily hydrolysed by aqueous KOH.
C–Cl bond length in chlorobenzene is shorter than C–Cl bond length in CH3–Cl.
What is the action of the following on ethyl bromide:
silver acetate
Arrange the following organic compounds in descending order of their reactivity towards SN1 reaction.
C6H5CH2Br, C6H5CH(C6H5)Br, C6H5CH(CH3)Br, C6H5C(CH3)(C6H5)Br
Which of the following is a primary halide?
Which one of the following halogen compounds is difficult to be hydrolysed by SN1 mechanism?
SN2 mechanism proceeds through intervention of ____________.
The process of separation of a racemic modification into d and l-enantiomers is called ____________.
SN1 reaction of alkyl halides lead to ___________.
Identify the end product (C) in the following sequence:
\[\ce{C2H5OH ->[SOCl2][Pyridine] A ->[KCN {(alc.)}] B ->[2H2O/H^+] C}\]
Optical activity of an enantiomeric mixture is +12.6° and the specific rotation of (+) isomer is +30°. The optical purity 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
Discuss the mechanism of alkaline hydrolysis of methyl bromide.
Which alkyl halide from the following pair would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
\[\begin{array}{cc}\ce{CH3CHCH2CH2Br}\\|\phantom{.........}\\\ce{CH3}\phantom{......}\end{array}\] or \[\begin{array}{cc}\ce{CH3CH2CHCH2Br}\\\phantom{}|\\\phantom{...}\ce{CH3}\end{array}\]
