Which of the following alkali metals is the strongest reducing agent in aqueous solution, and what is the primary thermodynamic factor responsible for this behavior?

Step-by-step solution

In aqueous solution, the reducing power of an alkali metal is determined by its standard electrode potential ( E^ ). The overall standard free energy change depends on three factors: sublimation enthalpy, ionization enthalpy, and hydration enthalpy. Although Lithium ( Li ) has the highest ionization enthalpy among alkali metals, its small ionic size results in an exceptionally high hydration enthalpy. This large release of energy during hydration more than compensates for the high energy required for ionization, ma