Question

Which of the following is not linear
A. \[CO_2\]
B. \[ClO_2^-\]
C. \[I_3^-\]
D. None of these

Answer 1

Hint: Linear geometry depicts the geometry around a central atom bonded to two other atoms positioned at a bond angle of \[180^o\].
Linear molecules like acetylene possess sp orbital hybridization for their carbon centers.

Complete step by step solution:Here in this question, we have to find out the molecule which has linear geometry.
A. \[CO_2\]
Carbon is the central atom here. It has four valence electrons.
Each oxygen atom is doubly bonded to the carbon atom. We know that in VSEPR theory, multiple bonds are considered as a single electron group.
So, there are two bond pairs on carbon.
So, it has a linear structure.

B. \[ClO_2^-\]
Chlorine is the central atom here. It has seven valence electrons.
One oxygen atom is doubly bonded and one is singly bonded to the chlorine atom. We know that in VSEPR theory, multiple bonds are considered as a single electron group.
So, there are two bond pairs and two lone pairs on the Cl atom.


Image: Structure of \[ClO_2^-\]
So, it has a bent structure.
So, B is correct.


C. \[I_3^-\]
In this molecule, there are three Iodine atoms, one of the atoms carries a negative charge which has 3 lone pairs of electrons and 2 bond pairs.
The three lone pairs are repulsive and take equatorial positions.
So, the structure is linear.
So, C is incorrect.

So, option B is correct.

Note: To specify the total valence electrons of a molecule, aggregate all the valence electrons of the atoms present in the molecule is taken, one is subtracted for every positive charge and one is added for every negative charge.
Geometry around the central atom is determined based on the sigma bond pair and lone pair. Pi bonds are not significant.