# Percent Composition of Hydrates

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Due:
November 4, 2012
Percent Composition of Hydrates
Lab Report
Michelle Sims

Due:
November 4, 2012
Percent Composition of Hydrates
Lab Report
Michelle Sims

Purpose:
Demonstrate proficiency in using the balance and Bunsen burner. Determine that all the water has been driven from a hydrate by heating your sample to a constant mass. Relate results to the law of conservation of mass and the law of multiple proportions. Perform calculations by using the molar mass.

Analyze the results and determine the empirical formula of the hydrate and its percentage by mass of water.

Hypothesis:
If the hydrated form of CuSO4 is heated then it will remove the water turning it to the anhydrous form then it will change from blue to white.

Materials:
* Balance
* Crucible and Cover
* Crucible and tongs
* Distilled water
* Spatula
* Stirring rod, glass
* Bunsen burner
* CuSO4, hydrate crystals
* Desiccator gauze
* Dropper or micropet
* Ring Stand
* Ring and pipe-stem triangle
* Weighing paper

Procedure:
1. Put on goggles and lab apron
2. Make sure equipment is clean, do not touch crucible after it has been heated, and let cool before weighing. 3. Place the crucible and cover on the triangle with the lid slightly tipped. Heat until the crucible is glowing slightly red. Record the mass 4. Using the spatula add 3g of copper sulfate hydrate crystals to the crucible and determine the mass. 5. Place the crucible on the triangle with the lid slightly tilted. Heat gently for 2-3 minutes and heat to crucible for minutes. You will observe a color change. Cool and record mass. 6. Repeat step 5 to verify the mass is correct.

7. Take part of your sample to rehydrate the crystals.
Observation: When the anhydrous form is reacted with water it returns back to its hydrated state. 8. Clean all lab materials and area

Results:
Mass of empty crucible and cover| 20.50g|
Initial mass of...