Chem 3100 Thursday 9am-1:45pm
Unknown #: 146 Fall-11
Organic Chemistry Midterm Report
13 October 2011
Table of Contents
Separation of Benzoic Acid and Acetanilide
Extraction and Purification of Caffeine from Tea
Extraction of Trimyristin from Nutmeg
Conversion of t-butanol to t-butyl chloride
8 Literature and Experimental Values of Benzoic Acid and Acetanilide 9 Experimental Caffeine IR
10 Literature Caffeine IR
11 Experimental Trimyristin IR
12 Literature Trimyristin IR
13 Experimental Tert- Butyl Chloride IR
14 Literature Tert-Butyl Chloride IR and RI
Separation of Benzoic Acid and Acetanilide
The best way to separate an acidic or basic compound from a mixture is through an extraction. With the use of the separatory funnel, the insoluble liquid (organic layer) is separated from the soluble liquid (aqueous layer). The purpose of this lab is to separate a mixture of benzoic acid from acetanilide. Procedure:
Obtain an unknown sample from instructor. The mixture is weighed out and place in a 125mL flask. 25 mL of methylene chloride was added to the mixture. Next the required KOH is added into the mixture, and refer to p. 117 from Wilcox &Wilcox.. The exception to this procedure is the use of a rotary evaporator instead of simple distillation. Data:
Mass of Mixture
Mass of Benzoic Acid
| 1.204 g
Mass of Acetanilide
| 1.372 g
| 65.07 %
% Composition of Pure Benzoic Acid
% Composition of Pure Acetanilide
| 53.26 %
Melting Point of Benzoic Acid
| 122-125 Degrees Celsius
Melting Point of Acetanilide
| 113-116 Degrees Celsius
The percent recovery of acetanilide and benzoic acid did not yield 100 percent. A possible cause of this was due to the loss of benzoic acid through filtration, so minuscule amounts of acetanilide residue were left in the round bottom flask. The literature melting points of acetanilide and benzoic acid are 113 degrees Celsius and 122 degrees Celsius. The literature values match the values obtained in the lab quite nicely; therefore, the two components contained no impurities.
Pure acetanilide and benzoic acid were successfully isolated from a solid mixture containing both products.
Extraction of Caffeine from Tea
Tea leaves contain 3-5% of caffeine. Caffeine can be isolated from tea by multiple extractions with dichloromethane. The purpose of this lab is to extract caffeine from tea and purify the caffeine using the sublimation apparatus. The extraction of caffeine from tea is relevant because caffeine is one of the most consumed drugs in the United States. Scientists can use Procedure:
Refer to p. 118-119 (D) in Wilcox & Wilcox. Use half the portions listed in the book accordingly. Also, purify the caffeine in groups of four using a simple sublimation apparatus. Refer to p. 102 in Wilcox & Wilcox for sublimation using a Petri dish. Data:
Mass of Tea
| 15.0085 g
Mass of Individual Crude
% Yield of Crude
Mass of Crude Group Caffeine
Mass of Pure Group Caffeine
| 0.0767 g
% Recovery from Sublimation
Individual % Yield from Tea
The most that can be obtained from the extraction of caffeine from tea is 3-5%. Therefore, the percent recovery from both the group and individual yield from tea will be low. The experimental low value is due to the multiple extractions of caffeine; most of the caffeine is lost due to this transfer. The literature IR values and the experimental IR values of trimyristin are mostly similar. The experimental IR has similar peaks, but none were really on target; Over all, the IR looks to be of caffeine. The similarities of the number of peaks and values show that the caffeine obtained is...
References: 2-Chloro-2-methylpropane. Chemblink.com. 2011. Web. 09 October 2011.
Chemical Book. Chemicalbook.com. Web. 09 October 2011.
SCHNITZLER, E. et al. Thermoanalytical study of purine derivatives compounds. Eclet. Quím. [online]. 2004, vol.29, n.1 [cited 2011-10-09], pp. 71-78 .
The Vibrational Spectra and Assignments of t-Butyl Chloride and t-Butyl-d9 Chloride, and the Calculated Ionization-Equilibrium, Deuterium-Isotope Effect J. C. Evans and ,G. Y. -S. Lo
Journal of the American Chemical Society 1966 88 (10), 2118-2122
Wilcox & Wilcox. Experimental Organic Chemistry: A Small-Scale Approach. New Jersey: Prentice Hall, 1995.
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