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प्रश्न
How the following conversion can be carried out?
Ethyl chloride to propanoic acid.
Write the chemical equation to convert the following:
Ethyl chloride to propanoic acid.
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उत्तर
\[\ce{\underset{Ethyl chloride}{CH3CH2Cl} ->[KCN/EtOH-H2O][nucleophilic substitution] \underset{Propanenitrile}{CH3CH2CN} ->[H+/H2O][hydrolysis] \underset{Propanoic acid}{CH3CH2COOH}}\]
संबंधित प्रश्न
Give reasons for the following:
(CH3)3C–O–CH3 on reaction with HI gives (CH3)3C–I and CH3–OH as the main products and not (CH3)3C–OH and CH3–I.
Which would undergo SN2 reaction faster in the following pair and why ?
Write the structures of A, B and C in the following:
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH(Br)CH2CH3 + NaOH ->[water]}\]
Write the mechanism of the following reaction:
\[\ce{{n}BuBr + KCN ->[EtOH-H2O] {n}BuCN}\]
The treatment of alkyl chlorides with aqueous KOH leads to the formation of alcohols but in the presence of alcoholic KOH, alkenes are major products. Explain.
Which of the following is a primary halide?
Which among MeX, RCH2X, R2CHX and R3CX is most reactive towards SN2 reaction?
An important chemical method to resolve a racemic mixture makes use of the formation of ______.
The increasing order of nucleophilicity would be:
Complete the following analogy:
Same molecular formula but different structures: A : : Non superimposable mirror images: B
Which reagent will you use for the following reaction?
\[\ce{CH3CH2CH2CH3 -> CH3CH2CH2CH2Cl + CH3CH2CHClCH3}\]
CCl4 is insoluble in water because:-
The number of chiral alcohol (s) with molecular formula C4H10O is ______.
Among the following compounds I - IV, which one forms a yellow precipitate on reacting sequentially with (i) NaOH (ii) dil. HNO3 (iii) AgNO3?
 |
 |
 |
 |
| I | II | III | IV |
Which of the following compounds will show retention in configuration on nucleophile substitution by OH− ion?
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 SN2 mechanism of methyl bromide using aqueous KOH.
Which alkyl halide from the following pair would you expect to react more rapidly by an SN2 mechanism? Explain your answer.
\[\begin{array}{cc}\ce{CH3CH2CHCH3}\\
\phantom{.....}|\\
\phantom{......}\ce{Br}\\
\end{array}\] or \[\begin{array}{cc}\phantom{.......}\ce{CH3}\\
\phantom{...}|\\
\ce{H3C - C - Br}\\
\phantom{...}|\\
\phantom{.......}\ce{CH3}\\
\end{array}\]
