Most cobalt compounds are Co(II) or Co(III). One such compound containing chloride and waters of hydration was analyzed with the following results: A 0.256g sample of the hydrate was dissolved in water and excess silver nitrate added. The silver chloride precipitate was filtered and dried and found to weigh 0.308g. A second sample of the hydrate was weighing 0.416g was dissolved in water and excess sodium hydroxide added. The hydroxide was heated in a flame to produce 0.145g of Co(III) oxide. Assuming one Co per formula unit, what is the molecular formula for the hydrate?

Hint: Find fraction due to Co. Find fraction due to Cl. Find the fraction due to water by difference. Find the empirical formula by assuming a fixed sample size and converting fractions to moles.