Calculate the mass percent of sand, sodium chloride and copper (II) sulfate in a sample which yields the following data: mass of sample = 1.088g, mass of sand = 0.2255g, mass of copper (II) oxide = 0.1994g (assume 100% yield for each of the copper (II) reactions). The reactions are as follows:
CuSO4 (aq) + 2NaOH (aq) = Cu(OH)2 (s) + Na2SO4 (aq)
Cu(OH)2 (s) = CuO (s) + H2O (l)
To calculate the mass percent of sand, sodium chloride, and copper (II) sulfate in the sample, we need to determine the mass of each component.
First, let's calculate the mass of copper (II) sulfate (CuSO4) in the sample. From the reaction, we know that 1 mole of CuSO4 reacts with 1 mole of Cu(OH)2. Therefore, the moles of CuSO4 are equal to the moles of Cu(OH)2.
Using the molar mass of CuSO4 (63.55g/mol), we can convert the mass of Cu(OH)2 (0.1994g) to moles:
moles of CuSO4 = (0.1994g) / (63.55g/mol) = 0.003138 mol
Since we assumed 100% yield for each of the copper (II) reactions, all the moles of CuSO4 in the sample have reacted to form Cu(OH)2.
Next, let's calculate the mass of sodium chloride (NaCl) in the sample. From the balanced chemical equation, we know that for every 1 mole of CuSO4, 2 moles of NaCl are produced.
moles of NaCl = 2 * moles of CuSO4 = 2 * 0.003138 mol = 0.006276 mol
Using the molar mass of NaCl (58.44g/mol), we can convert the moles of NaCl to mass:
mass of NaCl = (0.006276 mol) * (58.44g/mol) = 0.3664g
Finally, to calculate the mass of sand, we subtract the masses of copper (II) sulfate and sodium chloride from the total mass of the sample:
mass of sand = mass of sample - mass of CuSO4 - mass of NaCl
mass of sand = 1.088g - 0.3664g - 0.1994g = 0.5222g
Now we can calculate the mass percent of each component in the sample:
mass percent of sand = (mass of sand / mass of sample) * 100%
mass percent of sand = (0.5222g / 1.088g) * 100% = 48.03%
mass percent of sodium chloride = (mass of NaCl / mass of sample) * 100%
mass percent of sodium chloride = (0.3664g / 1.088g) * 100% = 33.70%
mass percent of copper (II) sulfate = (mass of CuSO4 / mass of sample) * 100%
mass percent of copper (II) sulfate = (0.1994g / 1.088g) * 100% = 18.28%
Therefore, the mass percent of sand, sodium chloride, and copper (II) sulfate in the sample is approximately 48.03%, 33.70%, and 18.28%, respectively.