Activities of Science

• State the purpose of the experiment:  The amount of water of hydration in copper sulfate hydrate was determined.
• Describe the procedure used:  Three samples of copper sulfate hydrate crystals were heated in a test tube over a Bunsen burner.  The samples were weighed before and after heating.
• Observe and record what happened:                                                                                                  Qualitatively:  The blue crystals turned into a white powder                                                      Quantitatively:  (x is the unknown):  CuSO₄ x H₂O(s)  -->  CuSO₄(s)  +  x H₂O(l)
• Organize the data in tables or graphs                                                                                                                    

  Sample	mass hydrate	mass CuSO4	mass H2O
  1	5.52 g	3.53 g	1.99 g
  2	4.62 g	2.94 g	1.68 g
  3	3.05 g	1.70 g	4.75 g

• Process the data and find regularities     

• Sample	mol CuSO4	mol H2O	mole ratio CuSO4/ H2O
  1	0.0221	0.110	1 / 4.98
  2	0.0184	0.0932	1 / 5.07
  3	0.0191	0.0943	1 / 4.94

                                                                                                                                                                                                          

• Interpret:  There are 5 moles of water of hydration per mole of CuSO₄.  The formula of the hydrate is CuSO₄^. 5 H₂O.