The correct increasing order of reactivity of alkyl halides with $CH_3NH_2$ is

(A) $C_2H_5-Br$
(B) $C_2H_5-I$
(C) $C_2Hs-F$
(D) $C_2H5-Cl$

Choose the correct answer from the options given below:

(C), (D), (A), (B)

The correct answer is Option (2) → (C), (D), (A), (B)

Alkyl halides react with amines such as CH₃NH₂ through nucleophilic substitution reactions (SN2).

The reactivity of alkyl halides in SN2 reactions largely depends on the leaving group ability of the halide ion.

Better leaving groups increase the rate of reaction

 The leaving group ability of halide ions follows the order: I⁻ > Br⁻ > Cl⁻ > F⁻

This is because larger halide ions form weaker C–X bonds and can stabilize the negative charge more effectively after leaving. Thus the reactivity of the given ethyl halides follows:

C₂H₅F < C₂H₅Cl < C₂H₅Br < C₂H₅I

Increasing Order of Reactivity (C) C₂H₅F < (D) C₂H₅Cl < (A) C₂H₅Br < (B) C₂H₅I