Question

The powerful reducing agent in aqueous solution is:

• A. Cs
• B. F
• C. Cl
• D. Li

Answer 1

The correct option is D Li

Due to the small size of the ion, lithium has the highest hydration energy which accounts for its reducing nature. This means that the polar water molecules will attach themselves more strongly to the small $L{i}^{+}$ ion.

Since the $L{i}^{+}$ ion is strongly hydrated, its formation from the lithium atom occurs more readily and is easily oxidised. Therefore, it acts as a powerful reducing agent.