Lab Report
Bijal Patel, 20467049
Partner: Poojan Parikh
T.A.’s: Long Pu
CHEM 123L, Section: 006, Rm: ESC 149
Tuesday February 4, 2013, 2:30pm-5:20pm
Experiment Done: Tuesday January 22, 2013
Introduction
Acetaminophen was first introduced in 1955 (Richman, 2004). It is an over-the-counter drug that relieves pain and reduced fevers. Acetaminophen is considered an alternate to aspirin since it does not irritate the stomach (Richman, 2004). It also has very low toxicity is it is used properly. Acetaminophen is cheap and easily obtainable from any pharmacy.
Acetaminophen is created when the amine group of p-aminophenol is acetylated by acetic anhydride. This creates an amide functional group and the by-product of this reaction is acetic acid. The crude acetaminophen will form as a white solid after the acetylated reaction. To turn this crude acetaminophen into a purified form, the recrystallization technique will be used.
The recrystallization technique is when the solid is dissolved and forced to precipitate as a crystal solid later on. The crude solid is dissolved through heating with a small amount of solvent, in this case, deionized water. The solution is then cooled to room temperature and later put into an ice bath which is when the crystals form. These crystals obtained are more pure since the impurities are dissolved in the cold solution. When cooling, the solution should remain undisturbed.
The purpose of this experiment is to determine the melting points of the crude and purified form of acetaminophen using a MelTemp melting point apparatus. Using capillary tubes, samples of the crude and purified solid will be tested. If the experiment is done properly, the crude solid should dissolve faster than the purified solid of acetaminophen. One must wear goggles and gloves at all times while working with acetic anhydride as it is corrosive.
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References: 1. Hine, R.; Martin, E. A Dictionary of Biology, 6 ed.; Oxford University Press: Oxford, 2008, pp. 13) 2. Newton, D.E. Amides. The Gale Encyclopedia of Science [Online] 2004, 1, pp. 159. 3. Richman, J.P. Analgesia. The Gale Encyclopedia of Science [Online] 2004, 1, pp. 181. 4. Seager, S.; Slabaug, M. Chemistry for Today: General, Organic, and Biochemistry, Thomson Brooks/Cole: Ogden, 2004, pp.342. 5. Stathopulos, S. Department of Chemistry 2013 First Year Chemistry (CHEM 123L) Laboratory Manual; University of Waterloo: Waterloo, ON, 2013; pp. 12-15.