Question

Arrange the following molecules by increasing bond polarity...?

Answer 1

The correct answer is Cl₂ <CCl₄ < PCl₃ < CaCl₂ < CsCl (most polar)

Cl₂ is nonpolar or least polar as there is no differentiation in electronegativity of the two atoms of chlorine producing amongst them. CCl₄ exhibits four C-Cl bonds. The C-atom is electropositive and Cl is electronegative. Therefore, there are four dipoles in CCl₄. Though, these dipoles cancel each other because of the tetrahedral geometry of the molecule. Therefore, CCl₄ is less polar in comparison to others, however, more polar in comparison to Cl₂.  

PCl₃ exhibits three dipoles because of electronegative chlorine atoms, and electropositive phosphorus atom. Though, the configuration of the molecule is trigonal pyramidal, producing it more polar in comparison to CCl₄. The CaCl₂ is ionic compound, therefore, polar in comparison to the covalent bond compounds.  

CsCl is ionic compound, however, more polar in comparison to CaCl₂, as there is the higher difference in electronegativity of Cs and Cl compared with that between the Ca and Cl.