The stronger reducing agent among all the halide ions is …………….

Answer

To determine the strongest reducing agent among the halide ions, we need to analyze the properties of the halide ions: fluoride (F⁻), chloride (Cl⁻), bromide (Br⁻), and iodide (I⁻).

### Step-by-Step Solution:

1. **Understanding Reducing Agents**:
- A reducing agent is a substance that donates electrons in a chemical reaction and gets oxidized in the process. Therefore, the stronger the reducing agent, the more readily it can lose electrons.

2. **Identifying Halide Ions**:
- The halide ions in question are F⁻, Cl⁻, Br⁻, and I⁻.

3. **Trends in the Halides**:
- As we move down the group from fluorine to iodine, the size of the halide ions increases. This is due to the addition of electron shells.

4. **Effect of Size on Reducing Power**:
- Larger ions (like I⁻) have their outer electrons further from the nucleus, making it easier for them to lose an electron compared to smaller ions (like F⁻).
- The nuclear charge also plays a role; a higher nuclear charge in smaller ions means they hold onto their electrons more tightly.

5. **Comparing the Halide Ions**:
- Fluoride (F⁻) is the smallest and has the highest nuclear charge, making it the weakest reducing agent.
- Chloride (Cl⁻) is larger than fluoride but smaller than bromide and iodide, so it is a stronger reducing agent than fluoride but weaker than bromide and iodide.
- Bromide (Br⁻) is larger than chloride and can lose electrons more easily than both fluoride and chloride.
- Iodide (I⁻) is the largest and has the lowest nuclear charge relative to its size, making it the strongest reducing agent among the halides.

6. **Conclusion**:
- Based on the trends in size and the ability to lose electrons, the strongest reducing agent among the halide ions is **iodide ion (I⁻)**.

### Final Answer:
The stronger reducing agent among all the halide ions is **iodide ion (I⁻)**.