# Experiment to Dehydrate a Bluestone

Topics: Water, Heat, Copper(II) sulfate Pages: 3 (750 words) Published: March 24, 2008
The Dehydration of a Bluestone
February.28.2008
Purpose
To determine the value of X in CuSO4 • xH2O.

Materials

Crucible
Blue Stone
Bunsen Burner
Bunsen Lighter
Test Tube
Water
Rheostat
Clay Triangle
Electronic Balance

Procedure
A clean crucible was taken and weighed on an electronic balance. The mass was then written down. 2g of bluestone was placed in the crucible and weighed. The mass of the blue solid was written down. The crucible was placed on a clay triangle and was heated by the Bunsen burner. When the blue color disappeared, the crucible was left to cool. After the crucible had cooled, the crucible was placed on the electronic balance to be weighed for its final mass of crucible and anhydrous solid. After the mass was written, a small amount of the anhydrous solid was taken and placed in a test tube. Then a few drops of water were added and the reaction was observed and written down.

Observations

Before
The solid was in a blue solid crystal form.
During
As it was heating, the blue solid slowly turned a whitish grayish color. After
The blue solid had turned a grayish white color and when water was added back to the anhydrous solid it turned blue again. •When the water droplets were added the bottom of the test tube felt hot.

Data
Mass of Crucible 14.82 g
Mass of crucible and CuSO4 •xH2O15.95 g
Mass of Crucible and anhydrous CuSO415.52 g

Calculations ------ Molar Mass of Copper Sulphate -> 64.0+32.1+16*4 = 160.1 g/mol Mass of Crucible14.82 gNo Calculation
Mass of Crucible and Solid15.95 gNo Calculations
Mass of Crucible and Anhydrous Solid15.52 gNo Calculations Mass of CuSO4 • xH2O15.95 g – 14.82 g = 1.130 g1.13 g Mass of CuSO415.52 g – 14.82 g = 0.70 g0.70 g
Mass of Water Lost1.13 g – 0.70 g = 0.43 g0.43 g
# of moles of CuSo415.52 – 14.82 = 0.70
0.70/160.1 = 0.044 mol0.0044 mol
# of moles of Water0.43 / 18 = 0.024 mol0.024 mol
Amount of water per mol of CuSO4...