The inhibition of Cu2+, Cd2+ and Zn2+ discharge reactions was studied in the presence of C4-C6 alcohols, phenol, benzyl alcohol and cyclohexanol (SAS) in 0.5 M Na2SO4 + 1 mM H2SO4 supporting electrolyte. It is found from the results that at high surface coverages by SAS, the inhibition is due to "sieve effect" which is different from that at low coverages. The true standard rate constant is proportional to exp[(- N ΔγAi)/(RT)] where ΔγAi is the extra energy (in the form of work) that must be done in order to create a free area required for a discharge reaction. © 1981.