Percentage Composition. But first, a word or two about hydrates. Hydrates. Hydrates are ionic cmpds (salts) that have water molecules bound to their ions. Examples: CuSO 4 5H 2 O Fe(NO 3 ) 3 9H 2 O CoCl 2 6H 2 O SnCl 2 2H 2 O Water can sometimes be removed by heating.
But first, a word or two about hydrates
Anhydrous cobalt(II) chloride, CoCl2
Cobalt(II) chloride hexahydrate, CoCl26H2O