${\mathrm{CO}}_2$is isostructural with

The correct option is C

${\mathrm{C}}_2{\mathrm{H}}_2$

The structures that have the same shape and hybridization are called the isostructural species.

Structure of ${\mathrm{CO}}_2$

The explanation for the correct answer

(c) ${\mathrm{C}}_2{\mathrm{H}}_2$

1. ${\mathrm{C}}_2{\mathrm{H}}_2$is the simplest alkyne chemical compound with the chemical name Acetylene.
2. The ethyne molecule features a triple bond between two carbon atoms, each of which is singly bonded to one other hydrogen atom. It can be noted that all four atoms align in a straight line with bond angles of approximately 180^o.

The explanation for the incorrect answers

(a) ${\mathrm{SO}}_2$

1. The molecular geometry of ${\mathrm{SO}}_2$ is bent, with a bond angle of 120°.

(b) ${\mathrm{NO}}_2$

1. NO₂ has an extra electron in an orbital on the nitrogen atom it will result in a higher degree of repulsions. However, if we take the one lone electron or the single-electron region there is less repulsion on the two bonding oxygen atoms. So the repulsions are not identical. As a result, the oxygen atoms are spread widely.
2. The bond angle is 134^o which is actually far from the ideal angle of 120^o. NO₂ molecular geometry will be bent.

(d) ${\mathrm{SnCl}}_2$

1. The structure of SnCl2 is a trigonal pyramidal shape ( V shape) due to the presence of lone pair of electrons.

Hence, the correct option is (C) as ${\mathrm{C}}_2{\mathrm{H}}_2$ and ${\mathrm{CO}}_2$ both are linear with a bond angle of 180° so ${\mathrm{CO}}_2$ is isostructural with ${\mathrm{C}}_2{\mathrm{H}}_2$.