This section contains Assertion and Reason type question each question has 4 choices (1)(2)(3)(4) out of which only one is correct
Assertion(A):In `H_2O` molecules O atom has two lone pair of electrons
Reason(R): The geometry of `H_2O` is tetrahedral due to `sp_3` hybridisation

Options

A. Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion
B. Both Assertion and Reason are correct but Reason is not the correct explanation of Assertion
C. Assertion is correct but Reason is incorrect
D. Both Assertion and Reason are incorrect

Answer

To solve the assertion and reason question regarding the H₂O molecule, we will analyze both the assertion and the reason step by step.

### Step 1: Analyze the Assertion
**Assertion (A): In H₂O molecules, the O atom has two lone pairs of electrons.**

1. **Understanding the Structure of H₂O:**
- Oxygen (O) has 6 valence electrons.
- Each hydrogen (H) atom contributes 1 electron to form a bond with oxygen.
- In H₂O, oxygen forms two single bonds with two hydrogen atoms.
- This accounts for 2 of the 6 valence electrons used in bonding, leaving 4 electrons.

2. **Determining Lone Pairs:**
- The remaining 4 electrons on oxygen are arranged as 2 lone pairs.
- Therefore, the assertion that "the O atom has two lone pairs of electrons" is **correct**.

### Step 2: Analyze the Reason
**Reason (R): The geometry of H₂O is tetrahedral due to sp³ hybridization.**

1. **Understanding Hybridization:**
- In H₂O, the oxygen atom undergoes sp³ hybridization.
- This hybridization involves one s orbital and three p orbitals mixing to form four sp³ hybrid orbitals.

2. **Determining Molecular Geometry:**
- Although the hybridization is sp³, the presence of two lone pairs affects the molecular geometry.
- The ideal geometry for sp³ hybridization is tetrahedral, but the actual shape of H₂O is bent (or V-shaped) due to the repulsion between the two lone pairs.
- Therefore, the statement that "the geometry of H₂O is tetrahedral" is **incorrect**; it is bent.

### Conclusion
- The assertion is **correct**: Oxygen in H₂O has two lone pairs.
- The reason is **incorrect**: The geometry of H₂O is not tetrahedral; it is bent.

### Final Answer
The correct option is **(3)**: Assertion is correct, but the reason is incorrect.

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