The behaviour of Au(210) in HNO3 and NaNO3 solutions was studied with cyclic voltammetry and differential capacity measurements as a function of concentration and temperature. The effect of concentration on both j-E profiles and C(E) curves suggests that for low concentrations and around zero charge potential, NO3- adsorption is similar to ClO4- adsorption on Au(210). For higher concentrations, the adsorption of NO3- ions at positive charges seems to occur to a greater extent than ClO4- ions. The entropy of formation of the electrochemical interface was derived from the effect of temperature in HNO3 solution. It was found to be qualitatively similar to what was observed in HClO4, solution.