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प्रश्न
Assertion: KCN reacts with methyl chloride to give methyl isocyanide.
Reason: CN– is an ambident nucleophile.
पर्याय
Assertion and reason both are correct and reason is correct explanation of assertion.
Assertion and reason both are wrong statements.
Assertion is correct but reason is wrong statement.
Assertion is wrong but reason is correct statement.
Assertion and reason both are correct statements but reason is not correct explanation of assertion.
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उत्तर
Assertion is wrong but reason is correct statement.
Explanation:
\[\ce{\underset{Alkyl cyanide}{R - Cl + KCN –> R - CN + KCl}}\]
Isocyanide is not obtained in this reaction. CN– is an ambident nucleophile.
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संबंधित प्रश्न
Write the structure of the major product in each of the following reaction :
In the following pair of halogen compounds, which compound undergoes a faster SN1 reaction?
Write the structure of the major organic product in the following reaction:
\[\ce{CH3CH2Br + KCN ->[aq.ethanol]}\]
Out of C6H5CH2Cl and C6H5CHClC6H5, which is more easily hydrolysed by aqueous KOH.
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.
What happens when ethyl chloride is treated with aqueous KOH?
The stability order for carbocation is _______.
(A) 2° > 3° > 1°
(B) 3° > 2° > 1°
(C) 3° > 1° > 2°
(D) 1° > 3° > 2°
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 optically inactive?
Which of the following pairs is/are correctly matched?
| Reaction | Product | |
| I | RX + AgCN | RNC |
| II | RX + KCN | RCN |
| III | RX + KNO2 | \[\begin{array}{cc} \phantom{.......}\ce{O}\\ \phantom{.....}/\\ \ce{R - N}\phantom{....}\\ \phantom{.....}\backslash\backslash\\ \phantom{.......}\ce{O} \end{array}\] |
| IV | RX + AgNO2 | \[\ce{R-O-N=O}\] |
An important chemical method to resolve a racemic mixture makes use of the formation of ______.
Which of the following compounds is optically active?
Identify the end product (C) in the following sequence:
\[\ce{C2H5OH ->[SOCl2][Pyridine] A ->[KCN {(alc.)}] B ->[2H2O/H^+] C}\]
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.
Elimination reactions (especially β-elimination) are as common as the nucleophilic substitution reaction in case of alkyl halides. Specify the reagents used in both cases.
CCl4 is insoluble in water because:-
The major product formed in the following reaction is:
In SN1 reactions, the correct order of reactivity for the following compounds:
CH3Cl, CH3CH2Cl, (CH3)2CHCl and (CH3)3CCl 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
