Arrange the following in the increasing order of their polarities and explain with reason: `B-Cl,Ba-Cl,Br-Cl,Cl-Cl`

Explanation

The increasing order of polarity of these bonds is `Cl-Cl lt Cl - Br lt Cl - B lt Cl-Ba`. Greater the difference in electronegativity betweenthe covalently bonded atoms, greater is the polarity of the bond. The electronegativities of B, BA, Br and Cl follows the order: `Cl gt Br gt B gt Ba`. consequently, polarity of the bonds formed by these atoms with Cl-atom progressively increases.