Adsorption of acetamide at the mercury/aqueous solution interface

Abstract

The adsorption of acetamide has been studied at mercury from aqueous solutions, containing 0.25 mol dm^–3 NaF and varying concentrations of acetamide in the range 0.063–2.53 mol dm^–3 by measuring the differential capacity of the mercury/solution interface. The corresponding variation in the activity of NaF was monitored by specific ion electrodes so that this could be considered in the analysis of the thermodynamic data. The derived surface excess of acetamide fits a Frumkin isotherm with the maximum surface excess varying with electrode charge density outside the range –11 ⩽σ/µC cm^–2⩽–5. The adsorption isotherm parameters are discussed, considering the hydrogen bonding which can occur between the solute and solvent molecules.