Finding the Percent of a Hydrate

Materials and Equipment:   1 hot plate            

1 evaporating dish              

                                  1 glass stirring rod                                                                                       1 crucible tongs

                                  cupric sulfate pentahydrate (CuSO4* 5H2O)

Procedure:  (From handout)   

 1) Find the mass of a clean, dry evaporating dish.

  2) Mass out 2.00g of cupric sulfate pentahydrate in a clean dry evaporating dish.

  3) Place evaporating dish on the hot plate and set the hot plate to 7.

  4) Hold the evaporating dish steady with crucible tongs while stirring the compounds as   it is heated. Try to break up any clumps. Continue heating until the substance has completely changed color.

5) Allow the anhydrous compound to cool. Find the mass of anhydrous powder remaining.

6) Carefully add water drop by drop  to the dry powder and record any observations. (Hint: check for temperature change by carefully touching the bottom of the evaporating dish)

Data:

Individual Data  

                     Class Data for CuSO4* 5H2O

                             Class Data for NaCl

Data Analysis:                               

Breakdown of CuSO4* 5H2O

Breakdown of NaCl

To find the percent of the hydrate in the CuSO4* 5H2O we subtracted the mass of the hydrous compound from the anhydrous compound to find the approximate mass of H2O. We then divided this number by the hydrous mass and multiplied by 100 to find the percent of the hydrate. To find the moles of CuSO4 we simply divided by the molar mass.         . To find the moles of water we