Question

Identify the correct order of rate of reaction for the compounds given below:

• A. CH3-CH2-F>CH3-CH2-Cl>CH3-CH2-Br (SN2 reaction)

Answer 1

All the given orders are incorrect based on standard organic chemistry principles. The question likely contains an error or requires specific context not provided.

Answer 2

Let's analyze each reaction type:

1. Aromatic Nucleophilic Substitution (SNAr):
   The rate-determining step involves the formation of a Meisenheimer complex. Generally, the leaving group ability order is F > Cl > Br > I due to fluorine's high electronegativity stabilizing the transition state. Therefore, the given order is incorrect.

2. SN1 Reaction:
   SN1 reactions proceed via carbocation intermediates. Alkyl carbocations are more stable than vinyl carbocations. Therefore, the given order is incorrect.

3. SN2 Reaction:
   SN2 reaction rates depend on leaving group ability, which follows the order I- > Br- > Cl- > F-. Therefore, the given order is incorrect.

4. Electrophilic Addition Reaction:
   The reaction rate depends on carbocation stability. Vinylamine (CH₂=CH-NH₂) forms a highly resonance-stabilized carbocation. Isobutylene ((CH₃)₂C=CH₂) forms a tertiary carbocation. Allylamine (CH₂=CH-CH₂-NH₂) forms a secondary allylic carbocation. The stability order is typically Vinylamine > Isobutylene > Allylamine. However, under acidic conditions, vinylamine can be protonated, deactivating it. Even with this consideration, the given order is not generally correct without specific contextual assumptions.

Conclusion: All provided orders are incorrect based on general organic chemistry principles. The question might contain an error or rely on specific, unstated conditions.