CuSO4.xH2O
Determine the percent by mass of water in your sample of hydrated copper (II) sulfate. Show your calculations clearly.
My work.
i got 10% is that correct
To determine the percent by mass of water in the sample of hydrated copper (II) sulfate (CuSO4.xH2O), we need to calculate the amount of water present as a percentage of the total mass of the compound.
First, we need to find the molar mass of CuSO4.xH2O. The molar mass of the anhydrous copper (II) sulfate (CuSO4) is 159.61 g/mol, and the molar mass of water (H2O) is 18.02 g/mol.
Next, we need to find the molar mass of the hydrated copper (II) sulfate. The molar mass of CuSO4.xH2O includes the molar mass of CuSO4 and the molar mass of x moles of water. Since the molar mass of water is 18.02 g/mol, the molar mass of x moles of water is 18.02x g/mol.
The molar mass of CuSO4.xH2O can then be calculated as follows:
Molar mass of CuSO4.xH2O = Molar mass of CuSO4 + Molar mass of xH2O
Molar mass of CuSO4.xH2O = 159.61 g/mol + 18.02x g/mol
Now, we need to determine the percent by mass of water. To do this, we'll use the following formula:
Percent by mass of water = (Mass of water in the compound / Total mass of the compound) * 100
Since the compound has a variable number of water molecules (x), we can assume we have 100 g of the compound to make calculations easier. Therefore, we need to find the mass of water (in grams) in 100 g of the compound.
Mass of water in 100 g of the compound = (Molar mass of water * x) / Molar mass of CuSO4.xH2O
Now, we can substitute the values into the formula to calculate the percent by mass of water:
Percent by mass of water = ((Molar mass of water * x) / Molar mass of CuSO4.xH2O) / 100 * 100
Now, let's calculate using your specific value of x = 10:
Percent by mass of water = ((18.02 g/mol * 10 moles of water) / (159.61 g/mol + 18.02 g/mol * 10)) / 100 * 100
Percent by mass of water = (180.2 g / (159.61 g + 180.2 g)) / 100 * 100
Percent by mass of water = (180.2 g / 339.81 g) / 100 * 100
Percent by mass of water = 0.5309 / 100 * 100
Percent by mass of water = 53.09%
Therefore, if you got 10% as the percent by mass of water, that answer is not correct. The correct percentage is approximately 53.09%.