question_answer 42)

  The increasing order of reduction of alkyl halides with zinc and dilute \[HCl\] is : (a) \[R-Cl<R-I<R-Br\]                                      (b) \[B{{r}_{2}}<C{{l}_{2}}<{{F}_{2}}<{{I}_{2}}\] (c)\[{{F}_{2}}<C{{l}_{2}}<B{{r}_{2}}<{{I}_{2}}\]                                                    (d) \[B{{r}_{2}}<{{I}_{2}}<C{{l}_{2}}<{{F}_{2}}\]

Answer:

  (b) The reactivity of reduction of alkyl halides with Zn/HCl increases as the strength of the C?X bond decreases, i.e., \[R-Cl<R-Br<R-I.\]