Question

The order of reactivity of the given haloalkanes towards nucleophile is :

• A. $RI > RBr> RCl$
• B. $RCl > RBr > RI$
• C. $RBr > RCl > R$
• D. $RBr > RI > RCl$

Answer 1

Answer: (A)

$RI > RBr> RCl$

Answer 2

For a given alkyl group, the order of reactivity is $\frac{R ??> R ?? r>R ??1>R ??}{increasing\, bond\, energy}$ decreasing halogen reactivity. This order depends on the carbon-halogen bond energy; the carbon-fluorine bond energy is maximum and thus fluorides are least reactive while carbon-iodine bond energy is minimum hence iodides are most reactive.