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Assertion (A): PhBr is less reactive tha...

Assertion `(A)`: `PhBr` is less reactive than `C_(2)H_(5)Br` towards `SN` reactions.
Reason (R): The forces of attraction between `RX` and `H_(2)O` molecules are weaker than those present between the molecules of `RX` and water molecules separately

A

Both `(A)` and `(R)` are true and `(R0` is the correct explanation of `(A)`.

B

Both `(A)` and `(R)` are true but `(R)` is not the correct explanation of `(A)`.

C

`(A) is true but `(R)` is false.

D

`(A) is false but `(R)` is true.

Text Solution

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The correct Answer is:
To solve the given question, we need to analyze both the assertion and the reason provided. ### Step 1: Analyze the Assertion The assertion states that phenyl bromide (PhBr) is less reactive than ethyl bromide (C2H5Br) towards nucleophilic substitution (SN) reactions. - **Explanation**: In phenyl bromide, the carbon-bromine bond has partial double bond character due to resonance. This resonance stabilizes the molecule, making it less reactive towards nucleophilic attack. In contrast, ethyl bromide is a primary alkyl halide, which is more reactive in SN2 reactions because it does not have this resonance stabilization. ### Step 2: Analyze the Reason The reason states that the forces of attraction between RX (alkyl halide) and H2O molecules are weaker than those present between the molecules of RX and water molecules separately. - **Explanation**: This statement is true because when alkyl halides are mixed with water, they do not form ideal solutions. Instead, they exhibit positive deviation from Raoult's law, indicating that the interactions between the alkyl halide and water are weaker than the interactions between the individual components. This can affect the overall reactivity of the alkyl halide in nucleophilic substitution reactions. ### Step 3: Conclusion Both the assertion and the reason are correct statements. However, the reason provided does not correctly explain why phenyl bromide is less reactive than ethyl bromide. The reason focuses on the interactions with water rather than the resonance stabilization of the carbon-bromine bond in phenyl bromide. ### Final Answer Both the assertion and reason are correct, but the reason is not the correct explanation for the assertion. Therefore, the correct option is **B**. ---
To solve the given question, we need to analyze both the assertion and the reason provided. ### Step 1: Analyze the Assertion The assertion states that phenyl bromide (PhBr) is less reactive than ethyl bromide (C2H5Br) towards nucleophilic substitution (SN) reactions. - **Explanation**: In phenyl bromide, the carbon-bromine bond has partial double bond character due to resonance. This resonance stabilizes the molecule, making it less reactive towards nucleophilic attack. In contrast, ethyl bromide is a primary alkyl halide, which is more reactive in SN2 reactions because it does not have this resonance stabilization. ### Step 2: Analyze the Reason ...
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