Introduction:
Acme Wallboard Co. Dear C. L. Louis, (Corporate Manager),
Hello, we are Chem- Mystery Inc. executives and several members of our team have been working with the mixture you sent us. We are. In order to determine how much magnesium sulfate heptahydrate by mass there is in the mixture, we used the law of constant composition that states samples of a pure compound always contain the same elements in the same mass proportions. A hydrate is a compound, typically a crystalline one, in which water molecules are chemically bound to another compound or an element. To find the percent of hydrate in the magnesium, calcium, and mixture we used a bunsen burner to heat a sample of each in a crucible. Refer to procedure and data table to see our findings. For example we found that the percent of hydrate in the mixture was 12%.
Equations and Calculation explanation: The first equation we will perform is to subtract the weight of the crucibles from each substance (heated and unheated). Next to find the percent of hydrate in each substance we will use the equation :
Original mass of substance- mass of heated substance= Hydrate = hydrate * 100= percent original mass hydrate
Then we had two equations
Percent of water in MgSO4 * Y + Percent of water in CaSO4 * X = percent of water in 100 100 acme wallboard mixture

and X+Y=100 ; X=CaSO4 and Y=MgSO4 . From there we will use the substitution method to get the solution to these two equations.

Materials:
Porcelain crucible and cover, clay triangle, ring stand, balance, bunsen burner, metal tongs, at least three grams of calcium sulfate hemihydrate, magnesium sulfate heptahydrate, and the mixture from Acme Wallboard.
Procedure:
1.) Put on safety goggles and apron.
2.) Support a clean porcelain crucible and cover on a clay triangle on a ring stand. Heat the crucible with a nonluminous flame for 2 to 3 minutes, to get rid of excess water.
3.) Put around 3 grams of the substance you are measuring in the crucible and weigh the crucible, cover, and contents to the nearest 0.01 g.
4.) Put the crucible and cover on the clay triangle. Heat gently at first then use a hot full flame for 15 to 20 minutes. The bottom of the crucible becomes a dull red color. Be sure to use a non-luminous flame.
5.) Cool crucible to room temperature and weigh it to the nearest 0.01 g.
6.) Reheat crucible strongly for 3-4 minutes to insure that the water is all driven off. Cool and reweigh. Repeat this step until 2 weighings match to the nearest 0.01g.
7.) Record data and perform calculations.
8.) Unplug balance, turn off gas to bunsen burner, clean up lab bench.

Diagram:

Data Table:

Mass of empty crucible
28.6 + 0.1 g (crucible for mixture)
32.2 + 0.1 g (crucible for MgSO4)
35.7 + 0.1 g (crucible for CaSO4)
Mass of CaSO4(H2O)1/2
38.7 + 0.1 g

Mass of heated CaSO4
38.5 + 0.1 g
38.5 + 0.1 g

Mass of MgSO4(H2O)7
35.1 + 0.1 g

Mass of heated MgSO4
33.6 + 0.1 g
33.6 + 0.1 g

Mass of Mixture
31.1 + 0.1g

Mass of heated Mixture
30.8 + 0.1 g
30.8 + 0.1 g

Calculation Table:
Equations:
Original total mass- crucible mass= original mass of substance.
Heated total mass- crucible mass= mass of heated substance. Original mass of substance- mass of heated substance= Hydrate = hydrate * 100= percent original mass hydrate

Percent of water in MgSO4 * Y + Percent of water in CaSO4 * X = percent of water in 100 100