Monday, May 27, 2019

Dehydration Lab Report

dehydration of 2-Methylcyclohexanol February 10, 2013 Introduction This experiment was done to demonstrate the practical use of dehydration reactions and produce three different produces. Dehydration reactions are reactions that involve the leaving of an -OH or -H group resulting in the formation of a double bond between two carbons. For the experiment we used 2-Methylcyclohexanol as a beginning reagent to dehydrate and possibly form 3-methylcyclohexene, 1-methylcyclohexene, or methylenecyclohexane.Drierite (Calcium Sulfate) was used as a drying agent to help break the alcohol and hydrogen groups from the carbons. unvoiced phosphoric acid was used as a catalyst to help move the reaction towards the products motioned above. To determine the successfulness of the experiment and the amount of product(s) recovered, IR spectroscopy, petrol Chromatography and pct yield calculations were used. Equations and Structures 6. References 1. 18. Dehydration of 2- Methylcyclohexanol. Organic C hemistry Lab 2040L. XU Chemistry, n. d. Web. 12 Feb. 2013. 2. Material rubber info Sheet 2-Methylcyclohexanol. Http//www. coleparmer. com/Assets/Msds/97403. htm. Coleparmer, 19 Mar. 1998. Web. 12 Feb. 2013. 3. Material Safety Data Sheet Methylcyclohexane. Sciencelab. com. Science Lab, 09 Oct. 2005. Web. 12 Feb. 2013. 4. Helmenstine, Anne M. , Ph. D. How to Write a LabAReport. About. com Chemistry. About. com Guide, n. d. Web. 23 Feb. 2013. . 5. Theoretical Yield. Theoretical Yield. Ed. University of Colorado at Boulder. Department of Chemistry and Biochemistry, n. d. Web. 23 Feb. 2013. . 7. Data Chemicals In Experiment B.P. Amount Used **Observations 2-Methylcyclohexanol 164-166C 0. 75mL Colorless liquid that had similar fume to gasoline. Calcium Sulfate (Drierite) 1193C Half Hickman noneffervescent tweed powder that resembled kitty litter. Phosphoric Acid 158C Approx. 1mL Clear liquid & Odorless 3-Methylcyclohexene 104C N/A Colorless liquid that had similar face to g asoline. 1-Methylcyclohexene * 110C N/A Colorless liquid that had similar smell to gasoline. Methylenecyclohexane 102C N/A Colorless liquid that had similar smell to gasoline. *Major Product **Not All Observations were noted in lab manual, many stated are from memory from the experiment. Observations It took a lot of time for the Hickman assuage to display any signs of condensation. The sand bathtub was adjusted to 60 power when 40 did not yield any visible results. The addition of a palpebra to the Hickman Still seemed to expedite the entire process. Colorless liquid began to collect rapidly in the first section of the Hickman Still. Weight of ampoule without Product 4. 284 grams Weight of Vial with Product 4. 550 grams Weight of Product 0. 266 gramsTheoretical Yield 0. 63 grams Percent Yield of Product 42% of Product was Recovered GC Interpretation The GC reading showed 3 peaks that were the products and one blip that is attributed to the air in the system. The different boi ling points of the different molecules in the sample cause the different peaks to be explicit in the GC. Of the 3 peaks, 1-Methylcyclohexene proved to be the most abundant product due its large area percentage. Percent Air Ignore Percent Methylenecyclohexane 1. 64555 = 2% Percent 3-Methylcyclohexene 17. 97600 = 18% Percent 1-Methylcyclohexene 79. 8650 = 80% IR Spectroscopy Reading of Sample Gas Chromatography Data 8. Calculations 9. Conclusions In conclusion, we were successfully able to dehydrate 2-Methlycyclohexanol to combine all three of the above products most notably 1-Methylcyclohexene. Adding approximately 1mL of 83% concentrated phosphoric acid to serve as the catalyst to the starting reagent and use calcium sulfate as a desiccant in the Hickman Still allowed the reaction to occur. The process of getting the products to condense on the first section of the Hickman Still took quite a while of time.After the product was collected, IR spectroscopy was used to determine the chemical make up and purity of the product. The IR reading of the product collected in comparison to the IR of the starting reagent 2-Methylcyclohexanol showed in the 3400 cm? 1 that the OH had went from a broad peak to a small blip. This gives evidence to the course of successfulness of the dehydration preformed but also shows that some OH was still in the product. The hypothetical GC data provided for this experiment demonstrates the purity of the sample along with the percent of each molecule found in the product. -Methlcylcohexene proved to be the major product of the reaction due to the 80% area in the GC data and the regions expressed in the IR reading. Due to human errors such as not allowing enough time for the product to collect, using more desiccants than needed, allowing for the temperature of the sand bath to reach the boiling point of 2-Methylcyclohexanol or not retrieving the entire product, the percent yield was only 42%. The experiment is considered a success becaus e all the evaluate products were produced and very little OH was found in the sample.

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