Question

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

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

Answer 1

Answer: (D)

$Cl{O}_3^{-}$, and $S{O}_3^{2-}$ ions are isoelectronic and isostructural. Structural formula of given options is as follows:

Number of electrons
$C{O}_3^{2-}=4+18+2=24;S{O}_3^{2-}=6+18+2=26$
$Cl{O}_3^{-}=7+18+1=26;N{O}_3^{-}=5+18+1=24$
Hence, $Cl{O}_3^{-}$and $S{O}_3^{2-}$ are isoelectronic as both have same number of electrons and are isostructural as both are pyramidal in shape.