one student weighed 1 g of copper power into a crucible and heated it to produce copper oxide. He was able to obtain only a 15% yield.

a. one student weighed 1 g of copper power into a crucible and heated it to produce copper oxide. He was able to obtain only a 15% yield. What was the total mass of the crucible contents (CUO plus unreacted Cu) after the reaction?

b. Another student heated 1 g of a red-pink hydrated salt until all the water had been removed. She was left with 0.546 g of dark blue solid. Is it possible that the hydrated salt was bienerite, CoSO4 * 7H2O? Why or why not? Show calculations.