Which of the following molecule forms linear polymeric structure
due to H-bonding ?

Options

A. `HCl`
B. `HF`
C. `H_(2)O`
D. `NH_(3)`

Explanation

To determine which molecule forms a linear polymeric structure due to hydrogen bonding, we will analyze the given options step by step.

### Step 1: Identify the Molecules
We have four molecules to consider: HCl, HF, H2O, and NH3.

### Step 2: Analyze HCl
- HCl does not form hydrogen bonds because the chlorine atom is relatively large and does not have a significant electronegativity difference with hydrogen to allow for hydrogen bonding.
- **Conclusion**: HCl is not the answer.

### Step 3: Analyze HF
- HF has a strong hydrogen bond due to the high electronegativity of fluorine.
- The structure of HF can be represented as F-H-F-H-F, where the hydrogen atoms can form linear arrangements due to hydrogen bonding.
- **Conclusion**: HF can form a linear polymeric structure.

### Step 4: Analyze H2O
- H2O has a bent molecular shape due to its two lone pairs of electrons on oxygen.
- While water can form hydrogen bonds, it does not form a linear polymeric structure; instead, it forms a tetrahedral arrangement.
- **Conclusion**: H2O does not form a linear polymeric structure.

### Step 5: Analyze NH3
- NH3 has a trigonal pyramidal shape due to the lone pair on nitrogen.
- Although NH3 can form hydrogen bonds, the NH bonds are relatively weak, and NH3 does not form a linear polymeric structure.
- **Conclusion**: NH3 does not form a linear polymeric structure.

### Final Conclusion
After analyzing all the options, the molecule that forms a linear polymeric structure due to hydrogen bonding is **HF**.

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