Experimental observations of the effects of solvation on the dehydrogenation reaction of Mg+(H2O)(n) to produce MgOH+(H2O)(n-1) are presented for n less than or equal to 6. The reaction is seen to occur spontaneously at room temperature for n>4. Ligand switching reactions are used to show the Mg+-OH bonds are stronger than Mg+H2O bonds. The results show the energy required to lose an H atom decreases with the number of water molecules attached because the magnesium changes oxidation state and this results in stronger interactions with the water ligands. Ab initio calculations are used to explain these observations.