Ryan EarlFormula of a Hydrate9/4/2015

I. Purpose

To identify some properties of hydrates and to determine the number of waters of hydration in an unknown hydrate.

II. Safety

We will be dealing with hot surfaces that could easily burn someone. As a result, safety goggles must be worn at all times, students must tie their hair back if it is too long, and students must avoid touching the surface of the Bunsen burner when it is hot.

III. Prelab Questions

Write a balanced equation showing gypsum heated to form plaster of Paris and water.

CaSO42H2O + heat CaSO4 + 2H2O

A 2.123 sample of washing soda was heated and all the water of hydration was lost. .787 g of the anhydrous sodium carbonate was left behind. Calculate x

2.123 - .787 = 1.336

2.123/105.9888=.007425

1.336/18.015=.07416

.07416/.007425=10

Na2CO3 x 10H20 x=10

IV. Procedures

Gather all material. Then, place the .5 gram unknown hydrates in the crucible, and place the crucible in the clay triangle. Plug in the Bunsen burner and heat up the surface. Place the crucible and clay triangle and the crucible on the Bunsen burner. Let it sit until all the water has evaporated. Then take the mass of the substance once again sing the analytical balance. This is the mass of the hydrate without water. Now you know how much hydrate there is and how much water there is. You can use stoichiometry to calculate the empirical formula of the unknown hydrate. Put away all lab equipment when done.

V. Data and Observations

Include any data or observations here. It must be organized in an easy to read fashion.

VI. Calculations

If applicable, type calculations here. If you wish to insert a picture of your calculations done on paper, that is acceptable as long as the picture is clear with good lighting.

VII. Postlab Questions

Type the questions and answers.

VIII. Conclusion

Type your conclusion here.

IX. Error Analysis

Type your error analysis here and include calculations for percent error or percent yield, if not already calculated in a prior section.