Chantelle-Joyce Sangcap
Ajani Brown
Sabrina Gauthier

Lab #16 Write Up

In order to conduct this experiment, the hydrates Copper (II) sulfate pentahydrate (CuSO4·5H2O), manganese sulfate monohydrate (MnSO4 1H2O), magnesium sulfate heptahydrate (MgSO4·7H2O), and Cobalt (II) chloride hexahydrate (CoCl2 6H2O) were used to find the percent of water in each one. In order to find the percent mass of water in each solution, the following formula was used: Mass of Water (in each solution) X 100 = the % of water in each solution Mass of Hydrate

The Results
The calculated percent mass of water for the four hydrates were:
CuSO4·5H2O = 36%
MnSO4
1H2O = 11%
MgSO4·
7H2O = 51%
CoCl2
6H2O = 46%

These four Percent masses assisted the process in correctly labeling each unknown hydrate.

Procedure for Conducting the Experiment:

All the necessary materials which were gathered were Safety Goggles, 2 Crucibles, unknown hydrate #1, Unknown hydrate #2, burner, striker, scoopula, scale, and iron ring holder. Prior to the experiment, goggles were put on by all members of the group, to enforce safety. First, the mass of the crucible was measured on the scale, which equaled 22.7g. Using the scoopula, Unknown Hydrate #1 was then put into the crucible. In order to find the mass, the crucible, containing the Unknown Hydrate #1, was weighed, which equaled 30.2g. The mass of the crucible was subtracted from the mass of the crucible with Unknown Hydrate #1, in order to find the mass of Unknown Hydrate #1 which equaled to 7.5g. Unknown Hydrate #1 was then carful observed. Our observation showed that the substance was blue and crystallized, it was fine, and it was composed of small particles. The crucible and Unknown Hydrate #1 was then carefully placed on a clay triangle, directly over the burner. The gas was then turned on and the striker was used to ignite the flame that would heat up the substance, removing hydration. We then carefully observed the heating substance, listening for a crackling noise (which is a sign that water is being emitted) and watching for steam. After no more crackling noises were heard and no steam was seen the flame was turned off, the tongs were used to remove the hot crucible from the iron ring and was placed on the granite table to cool.

While the new substance, formally Unknown Hydrate #1, was cooling, the mass of Unknown Hydrate #2 was taken on the scale, which weighed 0.7g. Our observations of Unknown Hydrate #2 were that the substance was white, composed of crystallized solids and fine grains. The crucible containing Unknown Hydrate #2 was then places on the same clay triangle over the burner. The gas was then turned on and the striker was used to start the flame. Once again we observed for crackling noises and steam, signs that the substance was becoming an anhydrate. After no crackling noises were heard and no steam was visible, the flame was turned off and the tongs were used to place the hot crucible on the granite table top.

While the crucible with Unknown Hydrate #2 was cooling, the mass of Unknown Hydrate #1 and the crucible was taken, which equaled 27.4g. The mass of the crucible (22.7g) was then subtracted from the anhydrate and the crucible 27.4g, giving us the mass of the anhydrate which was 4.7g. The difference of the hydrate and the anhydrate was taken, giving the mass of the total amount of water lost, which was 2.8g. Using the equation above to calculate the percent mass of water, the percent mass of the Unknown Hydrate # 1 equaled 37%.

Mass of Water (in each solution) X 100 = the % of water in each solution
Mass of Hydrate

2.8 X 100 = 37%
7.5
Because the percent mass of water was 37%, it was concluded that Unknown Hydrate 1 was copper(II) sulfate pentahydrate (CuSO4·5H2O)

The same procedure done to Unknown Hydrate #1 was done to Unknown Hydrate #2. However, the mass of the anhydrate and the crucible equaled 22.9g. The mass of the crucible (22.9g) was subtracted from the mass of the anhydrate and the crucible (22.5g), which gave us the mass of the anhydrate 0.4g.
Using the formula below the percent mass was then calculated:

Mass of Water (in each solution) X 100 = the % of water in each solution
Mass of Hydrate

0.3 X 100 = 43%

0.7
Since, the percent mass of Unknown Hydrate #2 was 43% it was concluded that Unknown Hydrate #2 was Cobalt (II) chloride hexahydrate (CoCl2 6H2O) In the end, the whole experiment concluded with a positive effect. By using the hydrates Copper (II) sulfate pentahydrate (CuSO4·5H2O), manganese sulfate monohydrate (MnSO4 1H2O), magnesium sulfate heptahydrate (MgSO4·7H2O), and Cobalt (II) chloride hexahydrate (CoCl2 6H2O), we were able to conduct this experiment.