Bond strength of halogen acids are

Options

A. `HF gt HCI gt HBr gt HI`
B. `HCI gt HF gt HBr gt HI`
C. `HCI gt HBr gt HF gt HI`
D. `HI gt HBr gt HCI lt HF`

Answer

To determine the bond strength of halogen acids, we need to analyze the bond dissociation energies of the acids formed by hydrogen and the halogens (F, Cl, Br, I). The bond strengths can be compared based on the size of the halogen atoms and their electronegativity.

### Step-by-Step Solution:

1. **Identify the Halogen Acids**: The halogen acids we are considering are HF (hydrofluoric acid), HCl (hydrochloric acid), HBr (hydrobromic acid), and HI (hydroiodic acid).

2. **Understand Bond Strength**: Bond strength is generally measured by bond dissociation energy, which is the energy required to break a bond. In this case, we are interested in the H-X bond where X is the halogen.

3. **Consider Atomic Size**: As we move down the group in the periodic table from fluorine to iodine, the size of the halogen atoms increases.
- Fluorine (F) is the smallest.
- Chlorine (Cl) is larger than fluorine.
- Bromine (Br) is larger than chlorine.
- Iodine (I) is the largest.

4. **Effect of Size on Bond Strength**: The larger the halogen atom, the longer the H-X bond becomes, which generally leads to a weaker bond due to decreased overlap of the atomic orbitals. Therefore, as we go from HF to HI, the bond strength decreases.

5. **Consider Electronegativity**: Electronegativity also plays a role in bond strength. Fluorine is the most electronegative element, which means it holds onto the bonding electrons more tightly compared to the other halogens. This results in a stronger bond for HF compared to HCl, HBr, and HI.

6. **Order of Bond Strength**: Based on the above considerations:
- HF has the highest bond strength due to its small size and high electronegativity.
- HCl has a lower bond strength than HF but is stronger than HBr and HI.
- HBr is stronger than HI.
- HI has the lowest bond strength because it is the largest halogen and has the least electronegativity.

7. **Final Order**: The bond strength of halogen acids in order from strongest to weakest is:
- HF > HCl > HBr > HI

### Conclusion:
The bond strength of halogen acids follows the order: HF > HCl > HBr > HI.