Question

What is the difference in the electronegativities of interhalogen compounds?

Answer 1

Electronegativity: “A qualitative measure of the ability of an atom in a chemical compound to attract shared electrons to itself is called electronegativity.”

Trend in electronegativity:

• Ongoing left to right in a period, the atomic radius decreases as the attraction between the nucleus and the valence(or outer)electrons increases. So, the electronegativity also increases.
• On going down the group, electronegativity decreases with an increase in atomic radius.

Interhalogen compounds: When two different halogens react with each other, interhalogen compounds are formed.

Difference in electronegativity of interhalogen compounds

• They can be assigned general compositions as $\mathrm{XX}\prime$ , ${\text{XX}}_3^{\text{'}}$ where $\mathrm{X}$ is halogen of larger size and $\mathrm{X}\prime$ of smaller size and $\text{X}$ is more electropositive than $\mathrm{X}\prime$.
• For example ,${\mathrm{IF}}_7$,the electronegativity of fluorine is more compared to iodine due to its smaller size.
• In an interhalogen compound, the difference in electronegativities of two halogen atoms polarises the bond.
• Interhalogen molecules are more reactive due to their polarity and weak bonding.