ADSORPTION OF N-ALIPHATIC ALCOHOLS ON MERCURY FROM AQUEOUS-SOLUTIONS OF LOW IONIC-STRENGTH - THE PROBLEM OF ADSORBATE ORIENTATION

The electrosorption behaviour of n-aliphatic alcohols from n-butanol to n-octanol on mercury from aqueous 0.1 M NaF and from aqueous 0.05 M Na2SO4 was determined from capacitive charge measurements by using a computerized chronocoulometric technique. The increase in the surface area occupied by one adsorbed alcohol molecule at maximum coverage by about 0.06 nm2 per CH2 group, the constancy of the differential capacity at maximum coverage for all alcohols investigated, an incipient second rise in all experimental adsorption isotherms as well as other trends, point to a flat orientation of the adsorbed alcohol molecules up to maximum coverage.