Question

Water molecule in liquid state forms............charged structure.

• A. Tetrahedral
• B. Hexagonal
• C. Planner
• D. Cuboidal

Hint:

The tetrahedral arrangement of water molecules is key to its physical anomalies:
- In ice, this tetrahedral arrangement is open and rigid, making ice less dense than liquid water.
- Upon melting, some hydrogen bonds break, allowing the tetrahedral network to collapse slightly, increasing the density of liquid water (peaking at \(4^\circ\text{C}\)).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
In a single water molecule (\(\text{H}_2\text{O}\)), the central oxygen atom is \(sp^3\) hybridized, containing two bonding pairs of electrons (attached to hydrogen atoms) and two non-bonding lone pairs.
In the liquid and solid states, intermolecular hydrogen bonding plays a dominant role in organizing these molecules into structured networks.

Step 2: Detailed Explanation:
Each water molecule is capable of forming up to four hydrogen bonds with neighboring water molecules.
The oxygen atom acts as a hydrogen-bond donor through its two hydrogen atoms.
It also acts as a hydrogen-bond acceptor through its two lone pairs of electrons.
This directional coordination results in a local geometry where each central oxygen atom is surrounded by four hydrogen atoms (two covalently bound and two hydrogen-bonded) pointing towards the vertices of a regular tetrahedron.
While ice forms an almost perfect, rigid tetrahedral crystalline lattice, liquid water maintains a highly dynamic, transient "flickering cluster" network.
Even in the liquid state at room temperature, water molecules preserve an average of \(3.4\) to \(3.6\) hydrogen bonds per molecule.
This retains a distorted but predominantly tetrahedral local structure.

Step 3: Final Answer:
Water molecule in liquid state forms a tetrahedral structure.