Assertion : The H-bond present in `NH_(3)` dissolved in water is best represented by : `H-underset(|)underset(H)(N)-H--underset(|)underset(H)(O)-H` and not by `H-underset(|)underset(H)overset(|)overset(H)(N)---underset(|)underset(H)(H)-O`
Reason : The `O-H` bond polarity is more compared to that `N-H` bond.

Options

A. If assertion is true but the reason is false
B. If assertion is false but reason is true
C. If both assertion and reason are true and the reason is the correct explanation of assertion
D. If both assertion and reason are true and the reason is not the correct explanation of assertion

Explanation

To solve the question, we will analyze the assertion and the reason provided, and then determine their validity based on our understanding of hydrogen bonding and molecular polarity.

### Step 1: Understand the Assertion
The assertion states that the hydrogen bond present in ammonia (NH₃) dissolved in water is best represented by the structure:
`H-N-H-O-H` rather than `N-H-H-N-H-O`.

### Step 2: Analyze the Hydrogen Bonding
Hydrogen bonding occurs when a hydrogen atom covalently bonded to a highly electronegative atom (like nitrogen or oxygen) interacts with another electronegative atom. In this case, NH₃ (ammonia) can form hydrogen bonds with water (H₂O).

### Step 3: Compare the Structures
1. The first structure `H-N-H-O-H` indicates that the hydrogen atom of NH₃ is forming a hydrogen bond with the oxygen atom of H₂O.
2. The second structure `N-H-H-N-H-O` suggests that there is no direct hydrogen bond between the hydrogen of NH₃ and the oxygen of H₂O, which is less representative of the actual interaction.

### Step 4: Evaluate the Assertion
The assertion is incorrect because the first structure accurately represents the hydrogen bonding interaction between NH₃ and H₂O. The hydrogen from NH₃ does indeed interact with the oxygen of H₂O, making the first representation more valid.

### Step 5: Understand the Reason
The reason states that the O-H bond polarity is greater than that of the N-H bond. This is true because:
- Oxygen is more electronegative than nitrogen.
- A greater electronegativity difference leads to a more polar bond.

### Step 6: Evaluate the Reason
The reason is correct. The polarity of the O-H bond is indeed greater than that of the N-H bond due to the higher electronegativity of oxygen compared to nitrogen.

### Conclusion
- The assertion is **false**.
- The reason is **true**.

Thus, the correct answer is that the assertion is false and the reason is true.

### Final Answer
Assertion: False
Reason: True

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