Question

Arrange the following alkyl halides in order of dehydrohalogenation.$C_2{H}_{5}I$,$C_2{H}_{5}Cl$,$C_2{H}_{5}Br$,$C_2{H}_{5}F$:

• A. $C_2{H}_{5}F$>$C_2{H}_{5}Cl$>$C_2{H}_{5}Br$>$C_2{H}_{5}I$
• B. $C_2{H}_{5}I$>$C_2{H}_{5}Br$>$C_2{H}_{5}Cl$>$C_2{H}_{5}F$
• C. $C_2{H}_{5}I$>$C_2{H}_{5}Cl$>$C_2{H}_{5}Br$>$C_2{H}_{5}F$
• D. $C_2{H}_{5}F$>$C_2{H}_{5}I$>$C_2{H}_{5}Br$>$C_2{H}_{5}Cl$

Answer 1

The correct option is B $C_2{H}_{5}I$>$C_2{H}_{5}Br$>$C_2{H}_{5}Cl$>$C_2{H}_{5}F$

Dehydrohalogenation order means is the order for the given compounds how easy to separate halogen from the compound.

$\to$ We, know that down the group in halogen as atomic size increases they can't hold bonds with other atoms properly due to low effective nuclear charges.

$C_2{H}_{5}I>C_2{H}_{5}Br>C_2{H}_{5}Cl>C_2{H}_{5}F$