Question

What is the molecular geometry of the $C{S}_2$ molecule?

Answer 1

Hint : We know by trying to apply VSEPR theory Valence shell electron pair repulsion theory in this question. Using the VSEPR theory, we can determine the number of bond pairs and lone pairs of electrons that are present on the central atom of the given compound and from there try to predict the geometry of the compound.

Complete Step By Step Answer:
The VSEPR theory Valence shell electron pair repulsion theory is basically a model used to determine the geometry of a molecule from the number of electron pairs surrounding the central atom of the molecule. According to VSEPR theory, for a given molecule the central atom has to be chosen and the total number of valence electrons must be counted and from the electron count of the central atom the structure of the molecule is predicted.
In this case, the carbon atom is surrounded by two regions of electron density, one for each double bond it forms with the sulphur atoms. This means that its steric number will be equal to Two. The carbon will thus be sp hybridized. It will use one s and one p orbitals to form the hybrids, and the remaining p-orbitals to form pi bonds with the two sulphur atoms.
 $\underset{\cdot \cdot }{\ddot{S}}=C=\underset{\cdot \cdot }{\ddot{S}}$
The molecular geometry will thus be linear, the basic $A{X}_2$ model.

Note :
The most important part in this kind of question is to know the valence shell electron count of the central atom and the contribution of the neighboring atoms to the electron count of the central. In this way by determining the total electron count of the central atom you can determine the geometry of a molecule.