Readily assembled mini-galvanic cells can be employed to compare their observed voltages with those predicted from the Nernst equation and to determine solubility products for silver halides and overall formation constants for metal-ammonia complexes. Results obtained by students in both an honors-level first-year course in general chemistry and an intermediate-level course for students majoring in chemistry, biochemistry, and biology agree well with data reported in the literature. In addition, these mini-galvanic cells can be used as concentration cells, together with a computer-generated calibration curve based on the Nernst equation, to determine the silver ion concentration in a dilute unknown solution of silver nitrate. (Contains 3 tables.)