The limiting-current electrochemical method

based on K3Fe(CN)6-K4Fe(CN)6-NaOH electrolyte system

is often used to investigate experimentally wall transport characteristics in power and chemical engineering fields.Accurate measurement of ferricyanide ion concentration is crucial for determining wall mass transfer coefficient.In this paper

the process of measuring ferricyanide concentration in K3Fe(CN)6-K4Fe(CN)6-NaOH electrolyte utilizing UV-VIS spectrophotometry is presented

including the measurement of absorption spectral curves

determination of the optimum absorption wavelength and the calibration of standard working curve.Results indicate that the maximum absorption (302 nm) for ferricyanide is unsuitable for concentration measurement because of the interference of ferrocyanide.The linear correlation between ferricyanide concentration and absorbance at wavelength of 420 nm is proposed and can be used to determine the ferricyanide concentration through UV-VIS spectrophotometry.In addition

the physical properties of 0.01 mol稬-1 K3Fe(CN)6-0.02 mol稬-1 K4Fe(CN)6-0.5 mol稬-1 NaOH electrolyte are measured and the correlations of density

kinetic viscosity and molecular diffusive coefficient vs temperature are presented.Both the concentration measurement of ferricyanide and the physical properties of K3Fe(CN)6-K4Fe(CN)6-NaOH electrolyte may offer valuable reference for the application of limiting-current electrochemical method.