Peaks in the voltammograms of germanium in acidic electrolyte are traditionally ascribed to a back-and-forth change between hydrogenated and hydroxylated surfaces. We report in-situ infrared spectroscopy measurements confirming this prediction and identify GeH2 species at the hydrogenated surface, as well as GeH species corresponding to (111) terrace sites, step (or facet boundary) sites, and sterically hindered or buried sites. Step sites are hydrogenated and reoxidized at higher potentials than terrace sites. The potential dependence of electron and hole surface concentrations indicates that the hydrogenation of the surface is accompanied by a negative shift of the flatband potential. Infrared absorption of ionic species demonstrates that this shift is due to a change in surface charge balanced by ions in solution, rather than to the dipolar change between GeH and GeOH. This is in contrast to previous reports. The surface roughness on the atomic scale accounts for the dependence of absorption intensities on infrared polarization and crystal orientation. Calculation of the electric-field map at a microfaceted surface/electrolyte interface shows that significant enhancements in IR sensitivity may be expected from (111) microfaceting of a (100) surface.