Reducing properties of halogen acid are

Options

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

Answer

To determine the reducing properties of halogen acids (HX), we need to analyze the trend in reducing power as we move down the group of halogens (Group 17) in the periodic table. Here’s a step-by-step solution:

### Step 1: Understand the Halogen Acids
Halogen acids are binary acids formed from hydrogen and halogens. The main halogen acids we will consider are HF (hydrofluoric acid), HCl (hydrochloric acid), HBr (hydrobromic acid), and HI (hydroiodic acid).

### Step 2: Analyze the Bond Strength
The bond strength of the HX bond decreases as the size of the halogen atom increases. This is because larger halogen atoms have longer bond lengths, which results in weaker bonds.

- HF has the strongest bond due to the small size of fluorine.
- HCl has a weaker bond than HF.
- HBr has a weaker bond than HCl.
- HI has the weakest bond among them.

### Step 3: Relate Bond Strength to Reducing Power
The reducing power of an acid is related to its ability to donate hydrogen ions (H⁺). As the bond strength decreases, the tendency of the acid to release hydrogen increases. Therefore, the reducing power increases as we move from HF to HI.

### Step 4: Establish the Order of Reducing Power
Based on the bond strengths and the ability to donate hydrogen, we can establish the decreasing order of reducing power:

- HI > HBr > HCl > HF

This means:
- HI has the highest reducing power.
- HF has the lowest reducing power.

### Step 5: Evaluate the Given Options
Now, we can evaluate the options based on the established order of reducing power:

1. HF has greater reducing power than HBr. (Incorrect)
2. HF has greater reducing power than HCl. (Incorrect)
3. HCl has greater reducing power than HBr. (Correct)
4. HBr has greater reducing power than HI. (Incorrect)

### Conclusion
The correct order of reducing power is HI > HBr > HCl > HF, and thus the correct option from the given choices is the one that states HCl has greater reducing power than HBr.