Pre-Lab Methanol

Topics: Acetic acid, Ethanol, Solvent Pages: 2 (506 words) Published: February 18, 2013
Substance| Structure| M.W. g/mol| Density g/cm^3| MP (C)| Hazards| Naphthalene| | 128.17| 1.14| 80.26| White crystalline solid, with odor| benzophenone| | 182.217| 1.11| 47.9| Barely hazardous, don’t get in contact with eyes or skin| Methanol| | 32.04| 0.79| -98| Extremely flammable|

Petroleum ether| | 86.18| 0.77| -95| Extremely Flammable|

Procedure: 1.
2.Add 80mg of naphthalene to Craig tube. Add few drops of methanol hot solvent. 3. Place tube in hot water bath.
4. Add methanol dropwise until all solid dissolves.
5. Remove tube from heat, cap with plunger, and cool to room temp 6. Put in ice bath for 5 min and then centrifuge to separate solvent and crysta 7. Determ ine melting point of impure sample and crystals, eigh purified sample and determine % recovery 8. FOR PART 2, Make sure not to add enough to dissolve impurity, just 1 9. Weigh out approx 250 mg of impure benzophenone.

10. Place impure into 25 or 50 ml beaker and add 8 ml preheated solvent 11. Filter with gravity filtration and cool benzophenone to room temp 12. ice bath, then filter crystals using Hirsch funnel and wash flask and crystals with small amount of cold petroleum ether 13.dry crystals on funnel by using vacuum for 5 min.

14. Determine melting point of impure sample and crystals, eigh purified sample and calculate % recovery.

Methanol| | -98 C| Methanol| 0.79 g/cm^3|

Hazards: Methanol= extremely flammable, and poisonous liquid from ingestion, inhalation, or absorption. Will cause headaches, fatigue, nausea, and sometimes death.
Acetylsalicylic Acid= severe stomach irritation if ingested.
Acetaminophen= Also severe stomach irritation, as well as inhalation irrita.
Ibuprofen= same as Acetylsalicylic Acid

Procedure: 1. Preheat a water bath to 70 C. Weigh the tablet before starting. Remove plastic 2. Crush tablet to power and place powder in a centrifuge tube with 2 mL of methanol. Cap and shake....
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