alum [KAL(SO4)2 times xH2O] is used in food preparation, dye fixation and water purification. To prepare alum, aluminum is reacted with potassium hydroxide and the product with sulfuric acid.
1) A 0.6815g sample of alum is heated to drive off the waters of hydration, and the resulting KAL(SO4)2 weighs 0.3709 g. Determine the value of x AND the complete formula of alum.
2) when 0.7939g of aluminum is used, 8.570g of alum forms. what is the percent yield?