Hydrated Crystal Lab Directions
1. Read pages 213 – 215 of your textbook.
2. Working with a partner, determine an experimental method that will allow you to verify
the empirical formula for Epson salt. The maximum amount that you may use is 5.0
grams of Epson salt.
3. After you develop a written procedure, show it to the teacher before proceeding.
4. Create a data table similar to the one at the bottom of this page
5. In your experiment, you must solve for the following:
 The experimental empirical formula for the compound
 The percent error in you experiment (the true formula is magnesium sulfate
hepta hydrate)
 Repeat the experiment and make at least one change that you think will reduce
the percent error.
6. In your conclusion, be sure to discuss:
 What caused the error
 Did your change reduce the error, why or why not?
 What else could you have tried to help reduce the error?
Sample data table:
Trial #
and
change
made
1 – no
changes
2–
changed
…
Mass of
crucible
Initial
mass
Final
mass
Mass of
water
Mass of
MgSO4
Empirical
formula
Percent
error