How to calculate theoretical and percent yield. My values are: .152 g magnesium turnings, 1.10 g of bromobenze, 5 g of dry ice. mass of obtained product = .515 g Page < 3a by-product. Separation of benzoic acid from biphenyl can be done by treatment with a basesuch as sodium hydroxide, which neutralizes the acid to form a water-soluble salt, whereasbiphenyl remains in the ether layer and can be discarded.11. Add to the separatory funnel 4 mL of 5% sodium hydroxide solution, shake contents withoccasional venting, allow layers to separate and collect into a labeled Erlenmeyer flask thebottom aqueous layer containing the sodium salt of the product.12. The upper ether layer remaining in the conical vial still contains benzoic acid that needs to beextracted. Repeat step 11 twice with 4 mL portions of sodium hydroxide solution for a total ofthree extractions and combine the bottom aqueous layers in the labeled Erlenmeyer flask.13. Discard the ether layer obtained after the third treatment/extraction with sodium hydroxide.14. Heat on a hot plate the Erlenmeyer flask containing the combined aqueous layers. Five minutes ofboiling will be sufficient to remove traces of ether dissolved in the aqueous layer.15. Remove the flask from the hot plate and let the contents cool for 5 minutes. Add dropwise withstirring 5 mL HCl and cool the content in an ice bath. Benzoic acid is freed from its salt andprecipitates as a white solid.16. Filter the solid product on a Hirsch funnel under vacuum and wash away traces of HCl by addingsmall portions of cold water totaling 4 mL. Dry the solid by keeping it under vacuum on theHirsch funnel for 20 minutes.17. Weigh the solid and calculate the percent yield of the crude benzoic acid obtained. Measure themelting point and compare it with literature value. Based on the melting point obtained, theinstructor will indicate if purification is necessary. Show product to the instructor beforediscarding it.Results to report- Percent yield of crude product and its melting point, including comparison with the literature value.of 3ZOOM + Page < 2>Procedure1. Add 0.15 g magnesium turnings in a dry 25 mL round bottom flask. If the turnings are not shinyscrape the surface with a spatula to remove the oxide layer that prevents the reaction to occur.Add a stir bar and attach a Claisen head provided with a drying tube filled with Dryrite™ and arubber septum on the open end.2. Approximately 10 mL of anhydrous diethyl ether is stored in a dry 10 mL volumetric flaskcovered with a rubber septum (an Erlenmeyer flask can be used). Portions of diethyl ether will betaken out of the flask throughout the experiment, preferably with a syringe and needle through theseptum. You will need to tilt the flask in order to get the liquid into the syringe.3. Place 0.70 mL bromobenzene into a preweighed conical vial and determine its weight. Add 4.0mL anhydrous diethyl ether from the volumetric flask using a syringe with needle and swirlgently. Take approximately 1.0 mL of solution using a syringe with needle and cap back the vial.The rest of the solution will be added in portions to the magnesium turnings.4. Insert the syringe needle through the rubber septum and add to magnesium dropwise and withstirring the bromobenzene solution, while keeping the round bottom flask on a hot plate at 60C°.Evolution of bubbles is expected as a sign that an exothermic reaction starts to take place after theinitial gentle heating of the mixture.5.If it fails to initiate the reaction, add a small crystal of iodine to the flask, under gentle heating(consult instructor).6.When reaction starts and bubbles are observed, some cloudiness can be seen developing in thesolution, and the mixture will boil without using the hot plate. Take another portion of 1.0 mLsolution prepared at step 3 and add it dropwise to the reaction mixture. Add the remainingsolution of bromobenzene slowly in 1 mL portions within 15 minutes. If bubble formation ceases,reheat the flask with a hot plate at about 60 C°, and if boiling becomes too vigorous, remove thehot plate and/or stop the dropwise addition of bromobenzene.7. Rinse the empty conical vial used for bromobenzene with 2.0 mL anhydrous diethyl ether and addit to the reaction mixture using the same syringe. Overall, the complete addition should takeapproximately 30-40 minutes and should lead to the consumption of magnesium and formation ofsome gray residue.8. In a 150 mL beaker, add very quickly about 5 g of crushed dry ice (no precise weighing isnecessary and use gloves). With a Pasteur pipette, add the reaction mixture cooled to roomtemperature and transfer it to the beaker containing dry ice. Cover the beaker with a watch glassand let it stand until the dry ice sublimes. What is left is a glassy material (frozen due to the lowtemperature of dry ice) containing the precursor of benzoic acid, a Grignard adduct.9. Grignard adduct is decomposed by treatment with 1 mL concentrated HCl (dropwise addition tothe beaker, with a stir bar). Unreacted magnesium is consumed by HCl and if there is solidundissolved, add 40 mL of ether. If solid is still undissolved, add 10 mL of water. The goal is toobtain two layers without any solids. If there is not enough time to finish, the experiment can befloakrof 3ZOOM+

First we find mass of main reactant 1. Bromobenzene: 157.01g/mol (Main reactant) 2. Benzoic acid:…

Answered: How to calculate theoretical and…

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...