Chem 225 labreport 20 - Grade: A PDF

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To: Kristen Dickerson – 16 From: Radhi Daya Date: October 16, 2016 Experiment #: 20 Partners: Harini Patel, Heidi Franz, Nho Dao

Introduction: The purpose of the experiment was to carry out the alkylation of sodium saccharin with iodoethane and analyze the product mixture to figure out the structure of the major product (N-ethyl saccharin or O-ethyl saccharin). N,N- Dimethylformamide is used as a solvent for this experiment because it is an aprotic solvent and nucleophiles react better in an aprotic solvent. Using the DigiMelt, the melting point of the product determined what product was formed, which was N-ethyl saccharin.

Observation and Data: The actual product appeared to be a white powder throughout and could not be distinguished between the two products of ethylsaccharins visually. The crystals appeared to be clear and did not take much time for them to form. Immediately after adding the 40

mL of water and shaking, crystals began to appear. Color changes included the solution with the iodoethane, which was yellow, to a clear and whitish solution when crystals were forming.

Ethyl saccharin

Mass of final

Melting point range

Percent yield

product 0.1036 g

92 C – 96 C

52.30%

Results and Discussion: The student found the product to be N-ethyl saccharin from the melting point, which was between 92 C and 96 C. The major product formed depending on which the nucleophile was attacked the most. N-ethyl saccharin was more stable because the ethyl group was bound to the oxygen, which gives carbon an sp3 configuration. Possible sources of error include not drying the product completely when vacuum filtrating, improper weighing of solutes, and lack of transporting each mixture without any loss of the mixture. The percent yield was found to be 52.30%. The product was found to be N-ethyl saccharin. Percent Yield = actual / theoretical x 100 52.30 % = 0.1036 g / 0.1981 g x 100 Mass of product: 0.1036 g Melting point range: 92 C – 96 C Experimental: Reaction: The student is to conduct the experiment under the hood. The student weighed 10.0 mmol of sodium saccharin and added 5.0 mL of N,N-dimethylformamide in a 125 mL Erlenmeyer flask. The mixture was heated in a 80 C water bath while the mixture was swirled until the solid dissolved. Then 0.80 mL of iodoethane was added and the mouth

of the flask was cover with aluminum foil. The mixture continued to be heated in a water bath with occasional swirling with a constant temperature of 80 C. Seperation: The student let the mixture cool to room temperature and added 40 mL of water and shook the flask until any liquid residue solidified. The flask was then cooled in an ice water bath and any solids inside were broken up with a stirring rod. The student collected the solid by vacuum filtration and washed twice with 5 mL portions of ice cold water. Analysis: The student measured the mass and melting point range of the product using the DigiMelt. From the given melting point ranges, the student determined whether the product was either N-ethyl saccharin or O-ethyl saccharin. References: -Reference for Lab Manual: Lehman, J. W. Operational Organic Chemistry; A ProblemSolving Approach to the Laboratory Course, 4th Ed.; Pearson Prentice Hall, 2009; pp 175-180. -Reference for Lab Notebook: Radhi Daya. Organic Laboratory Notebook, [16-17]....