The reactions of ethylene glycol on Mo(110) were studied using temperature-programmed reaction, infrared reflection absorption, high-resolution electron energy loss, and X-ray photoelectron spectroscopies. The major reaction pathway is double C-O bond scission to evolve gas-phase ethylene at 350 and 390 K. Both X-ray photoelectron and infrared spectra demonstrate the existence of two surface intermediates, a bidentate (-OCH2CH2O-) and a monodentate (-OCH2CH2OH) species, at saturation coverage of ethylene glycol. We demonstrate that all ethylene glycol in the mixed overlayer of mono- and bidentate species reacts via a bidentate surface intermediate. Furthermore, in contrast to previous studies on other surfaces, the dialkoxide ethylene glycol intermediate is shown to be more reactive than similar monoalkoxides on Mo(110). Finally, analysis of the infrared spectra demonstrates that the bidentate species adsorbs with C-2 (or lower) symmetry at 300 K.