The reducing power of a metal depends on various factors. Suggest the factor which makes Li, the strongest reducing agent in aqueous solution.
(i) Sublimation enthalpy
(ii) Ionisation enthalpy
(iii) Hydration enthalpy
(iv) Electron-gain enthalpy
The answer is the option (iii) Hydration enthalpy is a measure of the tendency of an element to lose an electron in aqueous solution. More negative the hydration enthalpy, greater is the ability to lose an electron, making it a strong reducing agent.