a. The Lewis diagram for GeH4 is:
The electron-pair geometry around the greaterthanorequalto atom in GeH4 is
There are lone pair(s) around the central atom, so the geometry of GeH4 is b. The Lewis diagram for SCl2 is:
The elect long-pair geometry around the S atom in SCI2 is
There are lone pair(s) around the central atom, so die geometry of SCl2 is
The Correct Answer and Explanation is :
Answers:
a. GeH₄ (Germanium Tetrahydride)
- Electron-pair geometry around the central atom (Ge): Tetrahedral
- Number of lone pairs on the central atom (Ge): 0
- Molecular geometry of GeH₄: Tetrahedral
b. SCl₂ (Sulfur Dichloride)
- Electron-pair geometry around the central atom (S): Tetrahedral
- Number of lone pairs on the central atom (S): 2
- Molecular geometry of SCl₂: Bent (V-shaped)
Explanation:
The Lewis structures of molecules help determine their electron-pair geometry and molecular shape by considering valence electrons, bonding pairs, and lone pairs.
(a) GeH₄ – Germanium Tetrahydride
- Germanium (Ge) belongs to Group 14 of the periodic table and has four valence electrons.
- Hydrogen (H) atoms each contribute one valence electron.
- The total valence electron count is 4 + (4×1) = 8.
- Ge forms four single bonds with four hydrogen atoms, using all its valence electrons.
- Since there are no lone pairs on the central atom, the electron-pair geometry follows VSEPR theory, which dictates a tetrahedral geometry with bond angles of approximately 109.5°.
- The molecular geometry is also tetrahedral since all electron regions are bonding.
(b) SCl₂ – Sulfur Dichloride
- Sulfur (S) belongs to Group 16 and has six valence electrons.
- Each chlorine (Cl) atom has seven valence electrons.
- The total valence electron count is 6 + (2×7) = 20.
- Sulfur forms two single bonds with chlorine atoms, using four electrons.
- The remaining four electrons remain as two lone pairs on sulfur.
- According to VSEPR theory, four electron regions (two bonds + two lone pairs) around sulfur adopt a tetrahedral electron-pair geometry.
- However, because two of these regions are lone pairs, the molecular geometry is bent (V-shaped), similar to H₂O.
- Lone pairs repel more strongly than bonding pairs, reducing the bond angle to around 103°-105°.
Thus, GeH₄ has a tetrahedral shape, while SCl₂ has a bent shape due to lone pairs on sulfur.