Question

Which of the following are isoelectronic and isostructural?

• A. ${\mathrm{NO}}_3^{-},{\mathrm{CO}}_3^{2-}$
• B. ${\mathrm{SO}}_3,{\mathrm{NO}}_3^{-}$
• C. ${\mathrm{ClO}}_3^{-},{\mathrm{CO}}_3^{2-}$
• D. ${\mathrm{CO}}_3^{2-},{\mathrm{SO}}_3$

Answer 1

The correct option is A

${\mathrm{NO}}_3^{-},{\mathrm{CO}}_3^{2-}$

The correct option is A.

Explanation for correct option:

1. Isoelectronic species are those that have the same amount of electrons but vary in nuclear charge.
2. The species that have distinct atoms but have the same hybridization and shape are called isostructural species.
3. The number of electrons in the compound is ${\mathrm{NO}}_3^{-}=32{\mathrm{e}}^{-}$; ${\mathrm{CO}}_3^{-2}=32{\mathrm{e}}^{-}$.
4. The hybridization of ${\mathrm{NO}}_3^{-},{\mathrm{CO}}_3^{-2}$ are ${\mathrm{sp}}^2,{\mathrm{sp}}^2$, respectively.
5. The shape of ${\mathrm{NO}}_3^{-},{\mathrm{CO}}_3^{-2}$ is trigonal planar.
6. So, they are isoelectronic and isostructural species.

Explanation for incorrect options:

Option B: ${\mathrm{SO}}_3,{\mathrm{NO}}_3^{-}$

1. The number of electrons in the compound is ${\mathrm{NO}}_3^{-}=32{\mathrm{e}}^{-}$; ${\mathrm{SO}}_3=42{\mathrm{e}}^{-}$
2. The hybridization of ${\mathrm{SO}}_3,{\mathrm{NO}}_3^{-}$ are ${\mathrm{sp}}^3,{\mathrm{sp}}^2$, respectively.
3. The shape of ${\mathrm{SO}}_3,{\mathrm{NO}}_3^{-}$ is pyramidal, and trigonal planar, respectively.
4. So, ${\mathrm{SO}}_3,{\mathrm{NO}}_3^{-}$ are isostructural species.

Option C: ${\mathrm{ClO}}_3^{-},{\mathrm{CO}}_3^{-2}$

1. The number of electrons in the compound is ${\mathrm{ClO}}_3^{-}=42{\mathrm{e}}^{-}$; ${\mathrm{CO}}_3^{-2}=32{\mathrm{e}}^{-}$
2. The hybridization of ${\mathrm{ClO}}_3^{-},{\mathrm{CO}}_3^{-2}$ are ${\mathrm{sp}}^3,{\mathrm{sp}}^2$, respectively.
3. The shape of ${\mathrm{ClO}}_3^{-},{\mathrm{CO}}_3^{-2}$ is trigonal planar, pyramidal, respectively.
4. So, ${\mathrm{ClO}}_3^{-},{\mathrm{CO}}_3^{-2}$ are isostructural species.

Option D: ${\mathrm{CO}}_3^{-2},{\mathrm{SO}}_3$

1. The number of electrons in the compound is ${\mathrm{CO}}_3^{-2}=32{\mathrm{e}}^{-}$; ${\mathrm{SO}}_3=42{\mathrm{e}}^{-}$
2. The hybridization of ${\mathrm{CO}}_3^{-2},{\mathrm{SO}}_3$ are ${\mathrm{sp}}^2,{\mathrm{sp}}^3$, respectively.
3. The shape of ${\mathrm{CO}}_3^{-2},{\mathrm{SO}}_3$ is pyramidal.
4. So, ${\mathrm{CO}}_3^{-2},{\mathrm{SO}}_3$ are isostructural species.

Final answer: ${\mathrm{NO}}_3^{-},{\mathrm{CO}}_3^{-2}$ is isoelectronic and isostructural.