Purpose: The purpose of this lab is to find out how many moles of water there are in one mole of Copper Sulfate (CuSO x HO) and the percent by mass of water in the hydrate. This will be accomplished by heating a determined mass of the hydrate to remove the water, and by measuring the salt left over.
Introduction: This laboratory experiment will be done to find out how many moles of HO are present per one mole in the hydrate CuSO. A hydrate is a compound that has a fixed number of water molecules. The water in this hydrate can be removed by heating it, and when all the water from the hydrate has been removed it becomes anhydrous. This means that the hydrate has become completely dry, and is without water. This is important because to find the number of moles of water present in one mole in the hydrate CuSO you must first heat the hydrate and make it anhydrous.
Hypothesis: In this experiment the amount of moles of HO per mole of CuSO in the anhydrous salt will be between 1-7. This amount will be obtained by heating the hydrate and determining the number of moles from the masses.
Materials:
* Brunson Burner * Ring Stand * Copper Sulfate * Evaporating Dish * Gas * Fume Hood * Scooper * Scale
Procedure:
1. Collect an evaporating dish and wash it to make sure there is no chemical residue on it 2. Weigh the mass of the evaporating dish and then tare the scale 3. Add about 2 grams of the hydrate and record the mass of the hydrate 4. Spread the hydrate across the bottom of the dish and place it on the ring stand inside the fume hood 5. Turn the gas on and place the Brunson burner underneath the evaporating dish on the ring stand 6. Heat the hydrate until the blue turns into a grayish white 7. Turn off the gas and then shut off the Brunson burner 8. Wait about five minutes for the hydrate to cool down 9. Reweigh the dish with the heated hydrate and record the final mass 10.