Hydrated Salts

Investigation of a Hydrated Salt

Table of Calculations:

„Ñ- Unknown #2

Weight of hydrate before heating .9989g

Weight hydrate after heating .6534g

Weight of water .3455g

Mole of water in hydrate .0192mol

Mole of anhydrous salt: CuSO4

.004094mol

CuCl2 .004859mol

CoCl2 .005033mol

Mole ratio of water to each of the anhydrous salts: CuSO4

4.69

CuCl2 3.95

CoCl2 3.81

Observations:

The unknown metal used in this experiment was metal number 2. Its initial color was a shade of light blue. As heat was applied to the crucible, the color of the metal began to get lighter. There was also some browning along the edges. Once the rubber policeman was used to stir the compound more water was able to evaporate from the metal sample. The final color was a light gray or a greenish-white.

Sources of Error:

One major source of error resulted from the stirring of the compound during the heating process. The rubber policeman was used and some of the moist part of compound stuck to the glass rod. Many attempts were made to return all of it back to the crucible