Name _________________________ Date _________________________ Period ___

 

Percent Composition of Epson Salt

 

Purpose: Determine quantitatively the (molar ratio) percent composition of Epson salts

(MaSO4 +    ?   H2O)

 

Procedure:

  1. Mass Crucible
  2. Fill less than ½ with Epsom Salts
  3. Mass Crucible + hydrate
  4. Light burner
  5. Heat hydrate
  6. Turn off burner
  7. Cool for 5 min
  8. Mass Crucible + MgSO4
  9. Input data into computer and print results
  10. Complete the following calculation in the space provided.

Data:

  1. Mass of crucible ______
  2. Mass of crucible + hydrate ________
  3. Mass of hydrate ______

Calculation

 

 

 

  1. Mass of anhydrous salt ______

Calculation

 

 

 

  1. Mass of water ________

Mg = 24.3 g/mol

H = 1.0 g/mol

O = 16.0 g/mol

S = 32.1 g/mol

 
 
Calculation

 

 

 

  1. Percent composition by mass ________

Calculation

 

 

 

  1. Percent composition by formula ______

Calculation

     

 

Conclusions:

Why is it necessary to let the crucible cool before massing it? 5%

 

 

 

Why should the mass of the crucible be measured immediately after it cools and not later? 5%

 

 

 

 

Find result from at least two other groups. (% comps)
 
Compare your results with the results of other members of you class. Are there differences? If so give reasons for the differences. 10%