Assertion : The `HF_(2)^(-)` ion exists in the solid state & also in liquid state but not in aqueous state.
Reason : The magniture of hydrogen bonds among HF molecules is weaker than that in between `HF and H_(2)O`.

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

Answer

To analyze the given assertion and reason, we will break down the information step by step.

### Step 1: Understanding the Assertion
The assertion states that the \( HF_2^{-} \) ion exists in the solid state and liquid state but not in the aqueous state.

**Explanation**:
- The \( HF_2^{-} \) ion is a dihydrofluoride ion, which can form through hydrogen bonding between HF molecules.
- In the solid state, these ions can stabilize through intermolecular forces, allowing them to exist as a solid.
- In the liquid state, the same intermolecular forces allow the ion to remain stable in a liquid form.
- However, in an aqueous state, the presence of water molecules disrupts the hydrogen bonding network that stabilizes the \( HF_2^{-} \) ion, leading to its instability and inability to exist in that state.

### Step 2: Understanding the Reason
The reason provided states that the magnitude of hydrogen bonds among HF molecules is weaker than that between HF and water.

**Explanation**:
- This statement is incorrect. The hydrogen bonding between HF molecules is actually stronger than the hydrogen bonding between HF and water molecules.
- The reason for this is that HF molecules can form strong hydrogen bonds with each other due to their high electronegativity and the small size of the hydrogen atom, which allows for closer interactions.
- In contrast, when HF interacts with water, the hydrogen bonds formed are not as strong because water molecules are larger and have a different orientation compared to HF.

### Step 3: Conclusion
Based on the analysis:
- The assertion is **true**: \( HF_2^{-} \) exists in solid and liquid states but not in aqueous state.
- The reason is **false**: The magnitude of hydrogen bonds among HF molecules is stronger than that between HF and water.

### Final Answer
- The assertion is true, but the reason is false. Therefore, the correct option is that the assertion is true and the reason is false.

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