Your name TA’s name
Your Partner’s name Lab Section
OBSERVATIONS:
A. SELECTING A RECRYSTALLIZATION SOLVENT
| |Solubility Test (cold) |Solubility Test (hot) |
|Water |insoluble |soluble |
|pet ether |insoluble |insoluble |
|ethanol |fairly soluble |readily soluble |
|acetone |very soluble |readily soluble |
After looking at the solubility of impure acetanilide in the four solvents, water seems to be the best choice as a recrystallizing solvent.
B. DECOLORIZING A SOLUTION OF IMPURE ACETANILIDE AND HOT
FILTRATION
2. 1.5637 grams of impure acetanilide
5. 38 ml total solvent volume
7. Added tip of carbon black to mixture and mixture almost boiled over!
8. 28 ml total solvent volume
C. ISOLATING THE RECRYSTALLIZED PRODUCT WITH VACUUM FILTRATION
2. Chilled crystals in ice bath for 19 minutes. collected flaky white crystals
Mass of watch glass and acetanilide = 22.5478
Mass of watch glass = 21.6903
Mass of recovered acetanilide = 0.8575 g
Mass of impure acetanilide = 1.5637 g
Percent recovered = 54.8 %
D. DETERMINING THE MELTING RANGE
Melting range of recrystallized acetanilide = 112 – 114 oC
Melting range of impure acetanilide = 105 – 111 oC
CONCLUSION:
In this experiment a technique was used that will be used frequently throughout the semester: Purification by recrystallization. This technique allows for the purification of a crude material. The small loss in yield is made up by