Electronic surface states at semiconductor/solution interfaces can mediate processes such as trapping and detrapping of majority and minority charge carriers, recombination, or charge transfer to or from the solution. We have calculated the complete impedance response due to these processes using a kinetic approach. Specific cases are discussed and diagnostic parameters for the capacitance and conductance are presented. Experimental results on nn-Si(111) in fluoride solutions are used to illustrate the obtained expressions.