Question

Reactivity order of halides for dehydrohalogenation is :-

• A. $R-F>\,R-Cl>\,R-Br>\,R-I$
• B. $R-I>\,R-Br >\,R-Cl>\,R-F$
• C. $R-I>\,R-Cl>\,R-Br>\,R-F$
• D. $R-F>\,R-I>\,R-Br>\,R-Cl$

Answer 1

Answer: (B)

$R-I>\,R-Br >\,R-Cl>\,R-F$

Answer 2

Reactivity of $R-X$ depends on bond length.

More be the bond length, easier for the $R-X$ to go for dehydrohalogenation.

Thus, correct order is :

$R- I >R- Br >R- Cl >R- F$