Question

The linear structure is assumed by:
This question has multiple correct options
A. $SnC{{l}_{2}}$
B. $NC{{O}^{-}}$
C. $C{{S}_{2}}$
D. $N{{O}_{2}}^{+}$

Answer 1

To tackle this question, one must really understand the Valence Shell Electron Pair Repulsion Theory (VSEPR) which helps in predicting the shape of the molecules. The Shape of the molecules is also dictated by the lone pair-lone pair and bond pair- bond pair repulsion. Therefore, if a lone pair is present on the molecule then it will change the bond angle of the molecule and hence, its shape.

Complete Solution :
- First of all we will draw the shape of the molecules, In $SnC{{l}_{2}}$, the valence electron in Tin are 4 and in Chlorine there are 7, therefore, there will be two bonds created and one lone pair will be left on the Tin, which will repel the bond pair and hence, the shape of the molecule will be bent.

- In $NC{{O}^{-}}$, there are four valence electrons on Carbon so it can form 4 more bonds to complete its octet, and in Nitrogen, there are 5 electrons and Oxygen has 6 valence electrons. Therefore, Nitrogen forms three bonds with Carbon and Oxygen forms a single bond. Since, there are no lone pairs it will result in a linear shape.

- In $C{{S}_{2}}$, again, Carbon has 4 valence electrons and Sulphur has 6 valence electrons and they both need 4 bonds to complete their octet, therefore , they form double bonds. Hence, this shape is also linear.

- In $N{{O}_{2}}^{+}$, Nitrogen has 5 valence electrons and Oxygen has 6 valence electrons and formal charge on the molecule is +1. Therefore, Nitrogen forms a double bond with both the Oxygen to complete them. This shape is also linear.

So, the correct answer is “Option B, C and D”.

Note: Every element wants to be stable and complete their octet, therefore they create bonds with other elements to share their electrons, this method is mostly valid to the elements belonging till the third period as it is a way. But, always calculate formal charge to understand the structure better.