Seona, we don't know yet whether you have Co(II) or the less common Co(III) nitrate. Also have no information about the water content in it (aqueous or not). Both are extremely hygroscopic, making 2.4,6 aqua complexes (and preferably hexaaqua complexes in aqueous solutions). Anhydrous Co(II) nitrate can also readily accept 6 EtOH as ligands in dry EtOH solution, probably also the three valent analog as well, although this itself is able to make stable coordination compounds only with nitrate ions alone in approriate solvents.