Question

Which of the following pairs of ions are isoelectronic and isostructural?

• A. $S{O}_3^{2-},N{O}_3^{-}$
• B. $Cl{O}_3^{-},C{O}_3^{2-}$
• C. $C{O}_3^{2-},N{O}_3{}^{-}$
• D. $Cl{O}_3{}^{-},S{O}_3^{2-}$

Answer 1

Answer: (C)

Isostructural chemical compounds have similar chemical structures.

Isoelectronic terms refer to two-atom, ions or molecules that have the same number of valence electrons.

Number of electrons

$C{O}_3^{2-}=6+2+24=32$

$S{O}_3^{2-}=16+2+24=42$

$Cl{O}_3^{2-}=17+24+1=42$

$N{O}_3^{-}=7+1+24=32$

Hence $C{O}_3^{2-}$ and $N{O}_3^{-}$ are isoelectronic and trigonal planar in shape.

Option C is correct.