On the basis of simple considerations, the standard free energy of formation of aquated cations is shown to be a linear function of the estimated free energy changes for the formation of oxide and hydroxide when a metal is dipped into an aqueous solution. A mechanism has been suggested for the nature of the film being formed on a metallic surface in an aqueous medium. Some possible implications of the present findings are indicated for processes involving metal deposition. A linear relation is also obtained between this free energy and the electronegativity of metals. This would imply a closer relationship than would normally be expected between free energy and electron density. -- AATA