The electron geometry and the molecular geometry of SCl2 are, respectively:
tetrahedral, bent
tetrahedral, trigonal pyramidal
trigonal planar, bent
linear, linear
The correct answer and explanation is :
The correct answer is tetrahedral, bent.
Explanation:
To understand the electron geometry and molecular geometry of SCl₂ (sulfur dichloride), let’s break it down step by step.
- Valence Electron Count:
- Sulfur (S) is in Group 16 and has 6 valence electrons.
- Each chlorine (Cl) atom is in Group 17 and has 7 valence electrons.
- Therefore, the total number of valence electrons in SCl₂ is:
[
6 (\text{from S}) + 2 \times 7 (\text{from Cl}) = 20 \text{ valence electrons}.
]
- Lewis Structure:
In the Lewis structure of SCl₂:
- Sulfur is the central atom, with two chlorine atoms bonded to it.
- There are two lone pairs of electrons on the sulfur atom, as sulfur needs to satisfy its octet, and chlorine atoms each have three lone pairs to satisfy their octet.
- Electron Geometry (VSEPR Theory):
VSEPR (Valence Shell Electron Pair Repulsion) theory predicts the electron geometry based on the number of electron pairs (bonding and lone pairs) around the central atom.
- In SCl₂, sulfur has two bonding pairs (one for each chlorine) and two lone pairs. This gives a total of four regions of electron density.
- According to VSEPR theory, four regions of electron density around a central atom give a tetrahedral electron geometry.
- Molecular Geometry (VSEPR Theory):
The molecular geometry describes the arrangement of only the atoms (not the lone pairs).
- The two lone pairs on sulfur repel the bonding pairs, distorting the shape of the molecule.
- The result is a bent molecular geometry, as the bonding pairs of electrons are pushed closer together, and the bond angle is less than 109.5°.
Thus, SCl₂ has a tetrahedral electron geometry due to the four electron regions (two bonding pairs and two lone pairs) around the central sulfur atom, but the molecular geometry is bent because the lone pairs cause a distortion.