What is the Molecular Geometry of SeS2
The correct answer and explanation is :
Molecular Geometry of SeS₂ (Selenium Disulfide)
The molecular geometry of SeS₂ is Bent (V-shaped).
Explanation:
To determine the molecular geometry of SeS₂, we follow VSEPR (Valence Shell Electron Pair Repulsion) theory, which helps predict the shape of molecules based on electron repulsion.
- Determine the Lewis Structure:
- Selenium (Se) is the central atom because it is less electronegative than sulfur (S).
- Selenium has 6 valence electrons, and each sulfur (S) atom contributes 6 valence electrons (since sulfur belongs to group 16 of the periodic table).
- Two sulfur atoms form single bonds with selenium, using 2 electron pairs (one for each bond).
- After bonding, selenium has two lone pairs of electrons remaining.
- Find the Steric Number (Electron Domains Around the Central Atom):
- Selenium has two bonding pairs (Se–S bonds) and two lone pairs of electrons.
- The total steric number is 4 (2 bonding pairs + 2 lone pairs).
- Predict the Molecular Shape Using VSEPR Theory:
- A steric number of 4 typically leads to a tetrahedral electron geometry if there are no lone pairs.
- However, two lone pairs of electrons exert strong repulsion, which pushes the sulfur atoms downward, creating a bent shape.
- This is similar to H₂O (water), which also has a bent shape due to lone pair repulsion.
- Bond Angles:
- The ideal bond angle for a tetrahedral arrangement is 109.5°, but due to lone pair repulsion, the angle decreases, typically around ~105° to 110°.
Final Answer:
- Molecular Geometry: Bent (V-shaped)
- Electron Geometry: Tetrahedral
- Bond Angle: ~105° – 110°
- Reason: Lone pair repulsions cause a deviation from linear geometry.