Draw the Lewis structure of H2O. Include any nonbonding electron pairs. Draw the molecule by placing atoms on the grid and connecting them with bonds. Include all lone pairs of electrons.
The Correct Answer and Explanation is :
Lewis Structure of H₂O
- Count Valence Electrons:
- Oxygen (O) has 6 valence electrons.
- Each Hydrogen (H) has 1 valence electron, and there are two hydrogen atoms.
- Total valence electrons = 6 (from O) + 1×2 (from H) = 8 valence electrons.
- Determine the Central Atom:
- Oxygen is less electronegative than hydrogen, so it will be the central atom.
- Place Atoms and Form Bonds:
- Place the oxygen atom in the center and the two hydrogen atoms on either side.
- Connect each hydrogen atom to the oxygen atom with a single bond (2 electrons per bond).
- This uses up 4 of the 8 total valence electrons (2 for each bond).
- Distribute Remaining Electrons:
- After forming bonds, 4 valence electrons remain (8 total – 4 used in bonds = 4).
- Place these 4 electrons as two lone pairs on the oxygen atom.
- Complete Structure:
- The Lewis structure of H₂O looks like this:
H
|
O
/ \
H .Explanation
In the Lewis structure of water (H₂O), we have a central oxygen atom bonded to two hydrogen atoms. Each hydrogen atom forms a single covalent bond with oxygen, utilizing 4 of the 8 total valence electrons. The remaining 4 valence electrons are arranged as two lone pairs on the oxygen atom.
The geometry of the H₂O molecule is bent or angular due to the repulsion between the lone pairs of electrons on the oxygen atom. According to VSEPR (Valence Shell Electron Pair Repulsion) theory, these lone pairs occupy more space than bonding pairs, leading to a bond angle of approximately 104.5 degrees.
Water’s unique properties, including its polarity, are a direct result of its molecular structure. The oxygen atom is more electronegative than hydrogen, which creates a dipole moment, resulting in a partially negative charge on the oxygen and partially positive charges on the hydrogen atoms. This polarity is responsible for many of water’s essential characteristics, including its solvent capabilities and high surface tension. Understanding the Lewis structure of H₂O is crucial in various fields, including chemistry and biology, as it lays the foundation for comprehending water’s behavior in chemical reactions and biological systems.