This thesis presents an investigation of the mass and electrochemical responses of gold electrode surfaces (both bare electrodes and zeolite-modified electrodes) using an electrochemical quartz crystal microbalance (EQCM). The study on bare gold electrodes demonstrates the validity of the Sauerbrey equation ' via' the redox reaction of the Ag+/Ag couple. ' In-situ' Ag+ ion exchange through the zeolite-modified-electrode was also detected 'via' the quartz resonator frequency and resistance changes. A qualitative relationship between the frequency and resistance change was developed. The redox of silver through the zeolite-modified-electrodes were also studied. The electrochemical responses were detected by cyclic voltammetry (CV) and double-potential-step-chronocoulometry (DPSC). Both techniques showed a quantitative contribution of resonance resistance to frequency of approximately -5.5Hz ohm-1.