Comment on each of the following observations: for M 2+ (aq) + 2e – → M(s) (where M = Ca, Sr or Ba) is nearly constant.

Question

Philoid · Accepted Answer

E^° of any M²⁺/ M electrode depends upon the following three factors:

⇒ Enthalpy of vaporization

⇒ Ionization enthalpy

⇒ Enthalpy of hydration

Since, the combining effect of three factors is approximately the same for Ca, Sr ad Ba, therefore, their electrode potentials are nearly constant.