Solved: In most of its ionic compounds, cobalt is either

Chapter , Problem 97

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In most of its ionic compounds, cobalt is either Co(II) or Co(III).One such compound, containing chloride ion and waters of hydration,was analyzed, and the following results were obtained.A 0.256-g sample of the compound was dissolved in water, andexcess silver nitrate was added. The silver chloride was filtered,dried, and weighed, and it had a mass of 0.308 g. A second sampleof 0.416 g of the compound was dissolved in water, and anexcess of sodium hydroxide was added. The hydroxide salt wasfiltered and heated in a flame, forming cobalt(III) oxide. Themass of cobalt(III) oxide formed was 0.145 g.a. What is the percent composition, by mass, of the compound?b. Assuming the compound contains one cobalt atom per formulaunit, what is the molecular formula?c. Write balanced equations for the three reactions described.