So there's a question in my chemisty workbook that goes like this:"The results of an investigation into the action of heat on copper sulfate-5-water, a blue crystalline solid are given below.The formula is CuSO4.5H2O and the mass of one mole is 250g.A 5.0 sample of the blue crystals is heated to form 3.2g of anhydrous copper sulfate. With further heating, this decomposes into a black powder and sulfur trioxide.Question 1. Name the black powderQuestion 2. Calculate the mass of the black powder. Show your working."How would you approach a question like this? I know the black powder is copper oxide, but how do you calculate its mass? THANKS A MILLION!! :DDD
Heating of CuSO4.5H2O is represented by this reaction: CuSO4.5H2O =====> CuSO4 + 5H2O(g) And heating of CuSO4 will yield Copper (II) Oxide and Sulfur Trioxide: CuSO4 + heat =====> CuO + SO3 So the answer to the first question is CuO (Copper II Oxide or Cupric Oxide) For the second question: mass of CuO = (mass of CuSO4.5H2O / molar mass of CuSO4.5H2O) x ( mole of CuSO4 based on the first chemical equation / mole of CuSO4.5H2O based on the first chemical equation) x ( mole of CuO based on the second chemical equation / mole of CuSO4 based on the second chemical equation) x molar mass of CuO That is: mass of CuO = (5 g / 250 g/mole) x (1 mole CuSO4 / 1 mole CuSO4.5H2O) x ( 1 mole CuO / 1 mole CuSO4) x 79.54 g/mol mass of CuO = 1.59 g ===> answer
