Question

Which one of the following correctly represents the order of stability of oxides, $X_{2}O;(X=\text{halogen})$?

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• A. $Br>I>Cl$
• B. $Br>Cl>I$
• C. $I>Cl>Br$
• D. $Cl>I>Br$

Answer 1

The correct option is C $I>Cl>Br$

In oxides of halogen, the bonds are mainly covalent due to small difference in electronegativity between the halogens and oxygen : the bond polarity, however, increases as we move from $F$ to $I$. The stability of oxides of iodine is greater than those of chlorine while bromine oxides are the least stable. Iodine-oxygen bond is stable due to greater polarity of the bond while the stability of the chlorine-oxygen bond is due to multiple bond formation involving d-orbitals of the chlorine atom. Bromine being in between lacks both these characteristics. Thus, the stability of oxides of halogens decreases in the order :
$I>Cl>Br>F$
Option (a) is correct