Recrystalization Lab Report
Essay by Hayden Smith • November 1, 2017 • Lab Report • 794 Words (4 Pages) • 1,043 Views
- Purpose: The objective of this experiment is to perform the synthesis of acetanilide from the reaction of acetic anhydride and aniline.
- Physical Properties:
Name | Chemical Formula | Density | Color | Melting/ Boiling Points(deg. C) | Solubility |
Acetanilide | C8H9NO | 1.22 g/cm3 | Colorless | MP: 114.3 BP: 304 | In Water<0.56 g/100 mL Soluble in ethanol, diethyl ether, acetone, benzene |
Aniline | C6H5NH2 | 1.02 g/cm3 | Colorless | MP: -6 BP: 184.1 | In water: 3.6g/100ml |
Acetic Anhydride | C4H6O3 | 1.08g/ml | Colorless | MP: -73.1 BP: 139.8 | In water: 2.6g/100ml soluble in benzene |
Toxic Effects:
Substance | Toxic Effect |
Acetanilide | Acute Effects: Irritant of skin and eyes. Chronic Effect: Contact dermatitis and eczematous skin eruptions, anemia and cyanosis |
Aniline | Probable Human Carcinogen Acute Effects: confusion, ringing in the ears, weakness, disorientation, dizziness, impaired gate, lethargy drowsiness, convulsions, loss of consciousness, coma. Direct Contact: skin burns, eye irritation, and inhalation causes wheezing and coughing Chronic Effects: Anemia, headaches, tremor, parathesis, pain, CNS depression, coma, cardiac arrhythmia. Heart, kidney and liver damage may also occur as secondary effects hemolysis. |
Acetic Anhydride | Acute effects: Tear drawing, corrosive to the eyes, the skin, and respiratory tract. Chronic Effects: asthma like reactions |
Procedure:
- Calculate the volume needed to prepare 2.0 g of aniline using the density of the substance.
- Wearing gloves, use a pateur pipet to transfer the volume of aniline into a 125-ml flask.
- Add 15 ml od D.I. water to the flask.
- Under the fume hood; swirl the flask slowly, while simultaneously adding 2.5ml of acetic anhydride.
- Record all measured quantities in data table. Make note of any changes that might occur during the addition of chemicals.
- After acetanilide precipitates during the reaction, recrystallization must occur.
- Add 50 ml of water and a boiling stone to the flask.
- Heat mixture on hot plate until all substances have dissolved.
- Following the removal of flask from hot plate, pour about 1ml to 1.5ml of the hot solution into a small beaker and allow to cool. *Use for comparison later
- Without having the flask contacting the hot plate, add a small amount of activated charcoal or norite to the flask. *1 spatula full is adequate
- Bring mixture to boil.
- Swirl solution and allow to boil for a few minutes.
- While the boiling is taking place assemble gravity filtration apparatus with a stemless funnel. *also prepare about 25ml of distilled water.
How to use Gravity Filtration: materials; ring stand with ring,clay triangle, filter paper, dry flask, and a stemless funnel. 1. Fold up a piece of filter paper(fluted filter paper) 2. Put the filter paper cone in the stemless funnel. 3. Support this in a ring in the ring of the ring stand with a wire or clay triangle. 5.Put the new dry flask under the funnel to catch hot solution. 6. Get the flask with the solution hot again. 7. Pour the hot solution into the funnel then wash the filter paper down with hot solvent. 8. Let the solution cool and clean crystals should form. If not boil some solvent away and let it cool again until you see crystals. *Do not boil till dryness.
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