Summer Research Program for Science Teachers
The Bronx High School of Science
The synthesis of Some Organic Compounds and their Representative Structures
AIM: How can we represent organic compounds in 3-dimensions?
Goggles and apron, balance, 3 to 5 pyrex test tubes (18 X 150mm), 1 pyrex test tube (13 X 100mm)
a test tube holder, utility clamp, ring stand, a Bunsen burner, iron ring, wire gauze, dropper pipette, litmus paper (blue), cotton, 2 beakers (50 and 100 ml), graduated cylinder 10 ml and 100 ml, an Erlenmeyer flask (250 ml), and distillation apparatus.
Discussion: The instructor should review bonding, hybridization and functional groups.
[9-12 Content Standard B- Structure and properties of matter]
Synthesis of Acetic Acid:
Place approximately 1 gram of NaC2H3O2 into a large test tube. Add 2 ml of 9.0 M H2SO4 CAUTION: H2SO4 causes severe burns; avoid skin contact. Warm the solution over a Bunsen burner using a test tube holder and carefully note and describe the odor. CAUTION: DO NOT POINT OPEN END OF TEST TUBE AT ANOTHER STUDENT OR YOURSELF. Remove a few drops of solution and add to 2 ml of distilled water in a small test tube. Observe its solubility and test with blue litmus paper. Record your observations. Note: Save some acid for the preparation of ethyl ethanoate.
Synthesis of Ethyl Ethanoate:
To the acetic acid prepared previously add 2 ml of ethanol. Caution: Alcohols are toxic and flammable. Avoid skin contact and inhalation of vapors. Keep away from flames. Warm the solution in a beaker of boiling water for 2 or 3 minutes. Pour the contents of the test tube into a small beaker note the odor. Record observations.
Synthesis of enthanol and purification (optional):
Place 50 ml of distilled water in a 250 ml Erlenmeyer flask, add
10 ml of molasses, and a few granules of yeast and stir. Place a cotton plug in the mouth of the flask and set aside for 24-30 hours. The solution will be converted into ethanol and carbon dioxide gas.
Optional/Teacher Demonstration: Alcohols can be separated by distillation at a temperature slightly higher than its boiling point of 78 C.
Synthesis of acetic acid, ethanol and
2. Have students write out structural formulas for the acid, ester and alcohol.
3. Using molecular modeling sets construct 3-dimensional structures.
4. Using Hyperchemlite draw and print-out structures for al three products formed.
1. What familiar odor was associated
with ethyl ethanotae?
2. Acetic acid is soluble in water. Explain. Why?
3. Explain how molecular modeling programs can be helpful to scientists.
[Teaching Standard B- Orchestrate scientific discourse]
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