Question

How would you use separation techniques to recover acetone, 4-carboxyazobenzene, 1-propanol, and cumene in a laboratory experiment.

Techniques learned are: Solvent recrystallization, thin layer chromatography, column chromatography, liquid-liquid extraction, distillation. (Would prefer not to do a distillation as this times a long time).

Your company has designed a new process to dye rubbers. The process uses cumene to swell the material allowing the organic dye 4-carboxyazobenzene to penetrate more easily. The resulting rubber is able to retain its color, and this is thought to be a longer lasting alternative to previous methods. The VP of ABC Rubber Company has contacted your firm, the Jimmy Stewart Chemical Company in an attempt to reduce overhead costs. He is interested in finding a way to recycle the reactants that go to waste, and the solvents used to clean. The ABC Rubber Company is one that utilizes this process every day and is looking to for a more economical way of cleaning the dye vats after each lot has been processed. Your team is interested in recovering the acetone used to clean the equipment as well as recover any unused dye. Their proprietary blend also contains a small amount of 1- propanol. Your immediate supervisor would like you and your lab partner to investigate the possibility of recovering as many components as possible. Your goal is to determine a successful experimental procedure that solves these key objectives: 1. Determine the amount of acetone that can be recovered at a purity 285%; 2. Percent recovery and characterization of dye; 3. Percent recovery and characterization of cumene. When dying rubber, the ABC Rubber company uses cumene with a mass-volume percent of 0.250% 4-carboxyazobenzene. The proprietary cleaning blend consists of acetone and 1- propanol (4:1 (v/v)). The sample you will receive to test your experimental procedure on consists of 10 mL of the dye mixture with 50 mL of added cleaning solution used to clean the vat. This provides a 60 mL total volume for you to use. Be sure to review past laboratory exercises, since the start of this semester, and identify relevant experimental procedures that will assist in accomplishing the objectives above. At the start of the laboratory period, students will hand in a single spaced, 12 pt Times New Roman style paper outlining the necessary experimental details needed to complete the exercise. The report for this laboratory period will consist of a business-style letter. The letter will not only address the procedure used, but also the observations and outcomes as you deem necessary, so that this procedure may be repeated successfully by the rubber company.

Answer 1

Initially if u do recrystallization the solid compounds can easily separate from liquids. After recrystallization filter the solid. In the liquid part Acetone and propanol cumene. The solid part 4-carboxyazabenzene. Later the liquids of acetone and isopropanol and cumene. These three can be separate rotary evaporator under reduced pressure. The acetone boiling point 56 oC and isopropanol boiling point 96 oC and cumene boiling point 153 o C. First acetone can be collect in receiver. The remaining liquids are isopropanol and cumene. By changing the receiver u can do again rotary evaporator under reduced pressure u can separate isopropanol and remaining liquid is cumene.