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Read the passage given below and answer the following questions:
Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.
Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.
Q. The most reactive nucleophile among the following is
- a)CH3O-
- b)C6H5O-
- c)(CH3)2CHO-
- d)(CH3)3CO-
Correct answer is option 'A'. Can you explain this answer?
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Read the passage given below and answer the following questions:Nucleo...
Smaller size the of the nucleophile (i.e., CH3O- more reactive it is.
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Read the passage given below and answer the following questions:Nucleo...
Nucleophile:
A nucleophile is a chemical species that donates an electron pair to form a covalent bond with an electrophile. Nucleophilic substitution reactions involve the substitution of a nucleophile for a leaving group in an organic molecule.
SN1 and SN2 Reactions:
Nucleophilic substitution reactions can proceed through two different mechanisms: SN1 (substitution nucleophilic unimolecular) and SN2 (substitution nucleophilic bimolecular).
- SN1 Reaction: In an SN1 reaction, the rate-determining step involves the formation of a carbocation intermediate. This intermediate is then attacked by a nucleophile, resulting in the substitution of the leaving group. SN1 reactions occur in two steps and are favored by tertiary alkyl halides due to the stability of the carbocation intermediate.
- SN2 Reaction: In an SN2 reaction, the rate-determining step involves a one-step concerted mechanism where the nucleophile attacks the alkyl halide while the leaving group departs. SN2 reactions occur in a single step and are favored by primary alkyl halides due to the absence of steric hindrance.
Factors Affecting Reactivity:
The reactivity of alkyl halides towards SN1 and SN2 reactions depends on several factors:
- Steric Hindrance: Steric hindrance refers to the hindrance or obstruction of a nucleophile's approach to the electrophilic carbon atom. SN2 reactions are hindered by bulky alkyl groups, while SN1 reactions are less affected by steric hindrance.
- Stability of Intermediate or Transition State: SN1 reactions involve the formation of a stable carbocation intermediate, so alkyl halides that can form more stable carbocations (e.g., tertiary alkyl halides) are more reactive in SN1 reactions. On the other hand, SN2 reactions do not involve the formation of a stable intermediate, so primary alkyl halides (which do not form stable carbocations) are more reactive in SN2 reactions.
- Polarity of Solvent: The solvent plays a crucial role in SN1 and SN2 reactions. Polar solvents stabilize the charged intermediates in SN1 reactions, making them more favorable. In contrast, polar aprotic solvents are preferred for SN2 reactions as they do not solvate the nucleophile excessively, allowing it to attack the alkyl halide more effectively.
Most Reactive Nucleophile:
Among the given options, CH3O- (methoxide ion) is the most reactive nucleophile. This can be explained based on the following points:
- Methoxide ion is a strong nucleophile due to the presence of a negative charge on oxygen.
- It is a small and compact ion, which reduces steric hindrance and allows it to approach the electrophilic carbon atom more easily.
- Methoxide ion is also a good base, which enhances its reactivity in nucleophilic substitution reactions.
- Since SN2 reactions are favored by primary alkyl halides, and methoxide ion is a strong nucleophile, it is the most reactive nucleophile among the given options.
Therefore, the correct answer is option 'A' (CH3O-).
A nucleophile is a chemical species that donates an electron pair to form a covalent bond with an electrophile. Nucleophilic substitution reactions involve the substitution of a nucleophile for a leaving group in an organic molecule.
SN1 and SN2 Reactions:
Nucleophilic substitution reactions can proceed through two different mechanisms: SN1 (substitution nucleophilic unimolecular) and SN2 (substitution nucleophilic bimolecular).
- SN1 Reaction: In an SN1 reaction, the rate-determining step involves the formation of a carbocation intermediate. This intermediate is then attacked by a nucleophile, resulting in the substitution of the leaving group. SN1 reactions occur in two steps and are favored by tertiary alkyl halides due to the stability of the carbocation intermediate.
- SN2 Reaction: In an SN2 reaction, the rate-determining step involves a one-step concerted mechanism where the nucleophile attacks the alkyl halide while the leaving group departs. SN2 reactions occur in a single step and are favored by primary alkyl halides due to the absence of steric hindrance.
Factors Affecting Reactivity:
The reactivity of alkyl halides towards SN1 and SN2 reactions depends on several factors:
- Steric Hindrance: Steric hindrance refers to the hindrance or obstruction of a nucleophile's approach to the electrophilic carbon atom. SN2 reactions are hindered by bulky alkyl groups, while SN1 reactions are less affected by steric hindrance.
- Stability of Intermediate or Transition State: SN1 reactions involve the formation of a stable carbocation intermediate, so alkyl halides that can form more stable carbocations (e.g., tertiary alkyl halides) are more reactive in SN1 reactions. On the other hand, SN2 reactions do not involve the formation of a stable intermediate, so primary alkyl halides (which do not form stable carbocations) are more reactive in SN2 reactions.
- Polarity of Solvent: The solvent plays a crucial role in SN1 and SN2 reactions. Polar solvents stabilize the charged intermediates in SN1 reactions, making them more favorable. In contrast, polar aprotic solvents are preferred for SN2 reactions as they do not solvate the nucleophile excessively, allowing it to attack the alkyl halide more effectively.
Most Reactive Nucleophile:
Among the given options, CH3O- (methoxide ion) is the most reactive nucleophile. This can be explained based on the following points:
- Methoxide ion is a strong nucleophile due to the presence of a negative charge on oxygen.
- It is a small and compact ion, which reduces steric hindrance and allows it to approach the electrophilic carbon atom more easily.
- Methoxide ion is also a good base, which enhances its reactivity in nucleophilic substitution reactions.
- Since SN2 reactions are favored by primary alkyl halides, and methoxide ion is a strong nucleophile, it is the most reactive nucleophile among the given options.
Therefore, the correct answer is option 'A' (CH3O-).
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Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer?
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Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer?.
Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer? for Class 12 2024 is part of Class 12 preparation. The Question and answers have been prepared according to the Class 12 exam syllabus. Information about Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 12 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer?.
Solutions for Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Class 12.
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ample number of questions to practice Read the passage given below and answer the following questions:Nucleophilic substitution reactions are of two types; substitution nucleophilic bimolecular (SN2) and substitution nucleophilic unimolecular (SN1) depending on molecules taking part in determining the rate of reaction. Reactivity of alkyl halide towards SN1 and SN2 reactions depends on various factors such as steric hindrance, stability of intermediate or transition state and polarity of solvent. SN2 reaction mechanism is favoured mostly by primary alkyl halide or transition state and polarity of solvent, SN2 reaction mechanism is favoured mostly by primary alkyl halide then secondary and then tertiary. This order is reversed in case of SN1 reactions.Q. The most reactive nucleophile among the following isa)CH3O-b)C6H5O-c)(CH3)2CHO-d)(CH3)3CO-Correct answer is option 'A'. Can you explain this answer? tests, examples and also practice Class 12 tests.
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