Question

Which one among the folloing alkali metal has the highest reducing power ?

• A. Na
• B. Li
• C. Rb
• D. K

Answer 1

The correct option is B Li

Li is the most powerful reducing agent.
Lithium has the highest hydration enthalpy which account for its high negative E value and reducing power
Although when we go down in the group tendency to donate electron increases as the outmost electron is more loosely held. So the reducing property should increase as we go down the group and Cs should be the most powerful reducing agent. but there is another factor, the hydration energy which is highest in the case of Li and hence more reducing power.