Question

What is the difference in the electronegativities of interhalogen compounds?

Answer 1

For answering this question we should first learn about the Interhalogen compounds. Interhalogen compounds are the compounds which are made up of two halogens (Fluorine, Chlorine, Bromine, Iodine or Astatine). The halogens react with one another to form interhalogen compounds. Interhalogen compounds have the general formula $X{Y_n}$ where $n = 1,3,5or7$ and X will be less electronegative atom from the two halogens forming the compound. We will discuss different types of interhalogen compounds and their properties to get the required answer.

Complete answer:
The interhalogen compounds are formed by two different atoms of halogens only. There are never more than two atoms of halogens in an interhalogen compound. Interhalogen compounds are generally of four types:
$AX:ClF,BrF,BrCl,ICl,IBr$
$A{X_3}:Cl{F_3},Br{F_3},{(IC{l_3})_2}$
$A{X_5}:Cl{F_5},Br{F_5},I{F_5}$
$A{X_7}:I{F_7}$
The Interhalogen compounds of type $AX$ and $A{X_3}$ are made by those halogens which have very small differences in their electronegativities. The interhalogen compound of type $A{X_5}$ and $A{X_7}$ are made by halogens in which large sized halogen is less electronegative and small sized halogen is more electronegative. This is because smaller atoms can be attached around a larger atom.
Interhalogen compounds are generally more reactive than the halogens. The difference between electronegativities of two halogen atoms in an interhalogen compound polarises the bond. Because of this polarity and weak bonding, Interhalogen compounds are more reactive.

Note:
All interhalogen compound are more reactive than halogens because bond between interhalogen compound $A - X$ , is weaker than bond between halogens $X - X$ but there is an exception in Fluorine as $F - F$ bond is weaker than any bond between halogens in an interhalogen compound.