The Percent of Water in CuSO4 5H2O
Problem: Determine the percent of water in CuSO4 5H2O.
Materials: CuSO4 5H2O, porcelain crucible, wire-ceramic triangle, tripod, balance, spatula, tongs and Bunsen burner
Safety: Use tongs when handling the hot crucible, never leave a flame unattended, wear goggles
Pre-Lab: An empty crucible has a mass of 18.35 g. During a lab, a sample of CoCl2 6H2O was placed in the crucible, the combined mass was 22.67 g. The sample was then heated over a flame to drive off the water. The final mass was 20.82 g.
1. Based on the results from the lab, determine the percent of water in the CoCl2 6H2O sample.
2. Based on the formula, calculate the actual percent of water in CoCl2 6H2O.
3. Calculate the percent error for this lab.
Procedure:
1. Obtain the mass of an empty crucible.
2. Add approximately 5.0 grams of CuSO4 5H2O to the crucible.
Obtain the mass of both the crucible and CuSO4 5H2O.
3. Place the crucible and CuSO4 5H2O on a clay triangle on a tripod.
(See Figure 1)
4. Remove the water from the sample by heating the CuSO4 5H2O
moderately for about eight minutes in the hottest part of the
Bunsen burner flame.
5. Allow the crucible to cool for several minutes. Use the tongs when
handling the crucible. Obtain the mass of the cool CuSO4 and the crucible.
6. Place the anhydrous CuSO4 in the appropriate waste container. Figure 1
The Percent of Water in CuSO4 5H2O
Data and Analysis:
Create a data table that includes the following information and then transfer the information from your observations to the table.
-Weight of crucible
-Weight of crucible and CuSO4 5H2O (before heating)
-Weight of CuSO4 5H2O
-Weight of crucible and CuSO4 5H2O (after heating)
-Weight of water lost
Conclusion:
For all calculations, SHOW YOUR WORK!
1. Describe the appearance of the CuSO4 5H2O before it was heated and after it was heated.
2. Using the results from the lab, calculate the percent of water in your sample.
3. Calculate the actual percent of water in CuSO4 5H2O from the formula.
5. Using the actual percent of water from the formula as the accepted value, calculate your percent error.
6. Calculate the percent of copper, sulfur and oxygen in anhydrous CuSO4.
The Percent of Water in CuSO4 5H2O
Date, Problem, Materials, Safety
Pre-Lab: An empty crucible has a mass of 18.35 g. During a lab, a sample of CoCl2 6H2O was placed in the crucible, the combined mass was 22.67 g. The sample was then heated over a flame to drive off the water. The final mass was 20.82 g.
1. Based on the results from the lab, determine the percent of water in the CoCl2 6H2O sample.
2. Based on the formula, calculate the actual percent of water in CoCl2 6H2O.
3. Calculate the percent error for this lab.
Procedure:
1.
2.
5.
Mention appearance
Visual, written out
Data and Analysis:
5 spaces
Conclusion:
1. Describe the appearance of the CuSO4 5H2O before it was heated and after it was heated.
2. Using the results from the lab, calculate the percent of water in your sample.
3. Calculate the actual percent of water in CuSO4 5H2O from the formula.
5. Using the actual percent of water from the formula as the accepted value, calculate your percent error.
6. Calculate the percent of copper, sulfur and oxygen in anhydrous CuSO4.