What is the molecular geometry of (H2O)?
What is the electron geometry of (H2O)? (The electron geometry takes into account the lone pair electrons as if they were atoms).
What is the formal charge of each hydrogen and also the oxygen in this water molecule?
The Correct Answer and Explanation is :
The water molecule (H₂O) exhibits a bent molecular geometry due to the presence of two lone pairs of electrons on the oxygen atom. These lone pairs exert greater repulsion on the bonding pairs, causing the hydrogen atoms to be pushed closer together. This results in a bond angle of approximately 104.5°, which is less than the ideal tetrahedral angle of 109.5°. citeturn0search3
Electron Geometry:
Considering both bonding pairs and lone pairs, the electron geometry of H₂O is tetrahedral. This arrangement accounts for the four electron pairs around the central oxygen atom: two bonding pairs and two lone pairs. The lone pairs occupy positions that minimize repulsion, leading to the observed bent molecular shape. citeturn0search4
Formal Charges:
To determine the formal charges of each atom in H₂O, we use the formula:
Formal Charge = Valence Electrons – (Nonbonding Electrons + ½ Bonding Electrons)
- Oxygen Atom:
- Valence electrons: 6
- Nonbonding electrons: 4 (two lone pairs)
- Bonding electrons: 4 (two single bonds with hydrogen)
- Formal Charge = 6 – (4 + 2) = 0
- Each Hydrogen Atom:
- Valence electrons: 1
- Nonbonding electrons: 0
- Bonding electrons: 2 (one single bond with oxygen)
- Formal Charge = 1 – (0 + 1) = 0
Since all atoms have a formal charge of zero, the H₂O molecule is neutral. citeturn0search4
For a visual explanation of the Lewis structure, valence electrons, formal charge, and molecular geometry of H₂O, you might find the following video helpful:
videoH2O Lewis Structure, Valence Electrons, Formal Charge, Shape or Molecular Geometryturn0search0