Davina Suselo CHEM 8M Tues 9:00AM 1/29/19 Introduction: Pre-Lab Questions 1. Which atom is oxidized in the reaction of benzhydrol with bleach? Redraw the structures and indicate the oxidation number of that atom in the starting material and product. Oxygen is oxidized in the reaction of benzhydrol with bleach. 2. What are the main differences you expect to find between the IR of the starting material and product? The main differences expected between the IR of the starting material and the product are that the starting material will have a higher IR value as the main difference between benzhydrol and benzophenone are the alcohol group and the ketone group, respectively. Because of this difference, it can be expected that the starting material will have higher IR value as the O-H stretch is larger than the C=O stretch. 3. Briefly explain how phase transfer catalysts work and why one is necessary in this experiment. Phase transfer catalysts work by having both non-polar and polar regions, so are able to be soluble in both water and organic solvents. As organic compounds, such as the ones in this experiment, benzhydrol, are not water-soluble, PTC must be used in this experiment to be able to be soluble as this experiment also utilizes bleach and aqueous NaClO solution. PTC is needed in order for tetrabutylammonium cation to successfully carry the ClO- ion from the aqueous solution to the organic phase where the reaction can occur. 4. What are some of the advantages of using bleach as an oxidizing agent? What other oxidizing agents could be used to carry out the same transformation? Some advantages of using bleach as an oxidizing agent is that it is cheap and easy, and it is aqueous solution of NaClO. Dess-Martin Periodinane and Jones Reagent would be some oxidizing agents that could be used to carry out the same transformation. 5. What are the two solvents used in the reaction? Will the aqueous layer be on the top or bottom in the extraction? The two solvents used in the reaction are EtOAc and tetrabutylammonium. The aqueous layer will be on the bottom in the extraction. 6. Calculate the moles of each reagent used, identify the limiting reagent, and calculate the theoretical yield of benzophenone (recall that catalysts cannot be limiting). Show your work. This study source was downloaded by 100000800331788 from CourseHero.com on 01-31-2023 21:59:56 GMT -06:00 https://www.coursehero.com/file/37820381/EXP-3-PRELAB-Qs/ Powered by TCPDF (www.tcpdf.org)
