Adsorption of 1,2-Propanediol and Methyl Cellosolve at Mercury— 0.10 m KCl aq Interface at 25 °C

Adsorption of 1,2-propanediol and methyl cellosolve (isomeric compounds) at Hg–0.10 m KCl (aq) solution interface evaluated through equilibrium double layer capacity measurements indicated congruency of adsorption isotherms with respect to both potential (E) and charge density (σM); applicability of Langmuir’s adsorption isotherm; quadratic dependence of Δ\barG° on E and single stable orientation with the hydrocarbon chain facing the electrode and functional group in solution throughout the coverage region, for both the compounds. Surface excess, standard free energy of adsorption and the anodic shift of Epzc, are greater while the charge corresponding to maximum adsorption is more negative, for methyl cellosolve than for the diol.