Question

The correct order of thermal stability is:

• A. $ICl>ClF>IF$
• B. $IF>ClF>ICl$
• C. $ClF>ICl>IF$
• D. $ClF>IF>ICl$

Answer 1

The correct option is B $IF>ClF>ICl$

As electronegativity difference between $X$ and $X^{\prime }$ (where $X^{\prime }$ is the more electronegative halogen) decreases, the thermal stability of interhalogen compounds decreases.
$\text{Electronegative difference};|X-X^{\prime }|\propto \text{ionic character}$
Therefore, the correct order of thermal stability is:
$IF>ClF>ICl$