Question

Amongst $N{O}_3^{-},As{O}_3^{3-},C{O}_3^{2-},Cl{O}_3^{-},S{O}_3^{2-}$ and $B{O}_3^{3-}$ the non-polar species are:

• A. $C{O}_3^{2-},S{O}_3^{2-}andB{O}_3^{3-}$
• B. $As{O}_3^{3-},CI{O}_3^{-}andS{O}_3^{2-}$
• C. $N{O}_3^{-},C{O}_3^{2-},andB{O}_3^{3-}$
• D. $S{O}_3^{2-},N{O}_3^{-}andB{O}_3^{3-}$

Answer 1

Answer: (C)

$N{O}_3^{-},C{O}_3^{2-},andB{O}_3^{3-}$

Molecules having zero dipole moment are non-polar in nature. In $N{O}_3^{-},C{O}_3^{2-}$ and $B{O}_3^{3-}$ due to the trigonal planar shape of molecules, the dipole moment along the three bonds cancel each other and the resultant dipole moment of the molecule is zero, Thus, these are non-polar in nature. While in $S{O}_3^{2-},As{O}_3^{3-}$ and $Cl{O}_3^{-}$ due to the presence of one lone pair of electron on each molecule their shape is trigonal pyramidal and the resultant dipole moment of the molecule is not zero. Hence, the molecules are polar in nature.