The theory for the 'total' ac voltammogram of a surface bound molecule is presented as well as the theory for the dc component and ac harmonics. The theory has been verified by comparing theoretical dc component and ac harmonic voltammograms to those extracted from a numerical simulation using a fast Fourier transform. The verification of theory with simulation indicates that FFT could be applied to experimental data thereby providing a large amount of information from each ac voltammogram. To obtain useful information by applying FFT to an experimental ac voltammogram, the voltammogram must be sampled with a greater frequency than is normally the case. The required order of magnitude of the sampling frequency can be indicated from the numerical simulation. We have found that good power spectra were obtained by sampling at similar to 16 kHz over a similar to 500 mV range.