Natural convection mass transfer in presence of small amounts of alcohols

The effect of methanol, ethanol, n-propanol and isopropanol on the rate of cathodic deposition of copper from acidified copper sulfate solution was studied. These alcohols caused a decrease in the limiting current by an amount ranging from 5.95 to 35.55%, depending on the type of alcohol and concentration. Langmuir adsorption isotherm was applied. The values of heat absorption and free energy of adsorption were calculated

Kinetic study of copper on zinc metal in ethanol-water mixtures

The cementation of copper on zinc metal in solutions at different concentrations of copper sulfate at 25C has been studied. It was found to be a first order reaction. Moreover, the rates of this reaction in 0.15 M copper sulfate solution were measured in a variety of ethanol-water media at five different temperatures [from 20 to 40C]. The correlation between the mass transfer coefficient and the dielectric constant was investigated. Also, the thermodynamic parameters of activation have been calculated. The isokinetic relationship revealed the existence of compensation effect, in which the solute/solvent interactions play an important role