Lab on the Radical Bromination of a Hydrocarbon...the balanced equation isC14H14 + 2Br2 ----> C14H14Br2 + 2HBrThe lab instructions are below...Please help with the following:1) What is the limiting reagent ...bibenzyl or bromine...show how to calculate2) Calculate the theoretical yield of the product (C14H14Br2) EXPERIMENT 11RADICAL BROMINATION OF A HYDROCARBONPURPOSE: To prepare an alkyl halide by direct light-initiated radical substitution. Todemonstrate basic reaction methods and stoichiometric calculations.READ ABOUT: mechanism of radical halogenation, micro ground glass jointwareEQUIPMENT: 10 mL round bottom flask, micro condenser, micro dryingtube, Hirsch funnel, vacuum flask, light source.CHEMICALS: bibenzyl, dichloromethane, bromine solution (10% v/v in dichloromethane),toluene, cyclohexeneHAZARDS: Bromine is toxic and corrosive. Avoid breathing its vapors or allowing it incontact with skin or eyes. Immediately wash any spill with sodium bicarbonate.Hydrogen bromide gas produced by this reaction is an irritating corrosive gas.Carry out the reaction using an acid gas trap. The product, 1,2-dibromo-1,2-diphenylethane, and other side products may be lachrymatory.In addition to the usual items, pre-lab work should include a structural andbalanced equation and the following:PRE-LAB:a) Calculate the approximate mass of bibenzyl needed according to the procedure below.b) Calculate the number of moles of bromine to be used.c) Using (b) and the equation above, determine the limiting reagent.d) Using (c) and the equation, calculate the theoretical yield of productPROCEDURE:1) Assemble the apparatus as shown in Figure8. In the drying tube, place a small,loose plug of glass wool near the bend,fill the tube loosely with KOH flakes,and close with another loose glass woolplug. Support the entire apparatus on aring stand with a clamp on thecondenser.2) Disconnect the flask and measure 1.4millimoles of bibenzyl directly into it.Add 2 mL of dichloromethane andswirl the flask to dissolve all thebibenzyl. Reconnect the flask to thecondenser.Drying tabeKOHGlass woolFIGURE 8Condenser10 ml. Round-bottom flask3) Move the entire setup into a hood and remove the drying tube. Using the pipet provided,carefully measure about 2.0 mL of 10% bromine-dichloromethane solution and add itthrough the top of the condenser.4) Replace the drying tube on the apparatus. Swirl the mixture gently to mix. Carry the entireapparatus to the source of light. This is preferably direct sunlight, but may be an intenselamp.5) Upon exposure to light a reaction should occur. Hydrogen bromide gas bubbles are expelledfrom the reaction solution, the bromine color may start to fade, and a white, finelycrystalline solid precipitates in the reaction flask.6) Swirl the flask every few minutes to mix the reaction suspension and expose fresh solution tothe light. Expose the reaction to light for 15 to 20 minutes, or until all the bromine colorhas discharged. 7) Move the setup into a hood and remove the drying tube. Allow the mixture to "breath" for afew minutes so that the bulk of the remaining HBr can escape. Do not remove themixture from the hood until no HBr fumes are observed.8) Add cyclohexene dropwise through the condenser, with until the unreacted bromine is AUTconsumed. Any reddish material should disappear and the suspension should have awhite to yellow color.e9) Cool the flask for a few minutes in an ice bath.10) Vacuum filter the suspension with a Hirsch funnel and vacuum flask. Wash the crystallinemass with 2 mL of ice-cold distilled water and air-dry the material for several minutes onthe funnel.11) Recrystallize the crude product from toluene. Add the air-dried crystals, a boiling stick,and about 10 mL of toluene to small beaker. Bring this suspension just to boiling on asteam bath and add small portions of toluene to the boiling solution until the white solidjust dissolves. Remove the flask from the heat source, remove the boiling stick and allowthe solution to cool slowly to room temperature. Crystals of the product should reform.12) Collect the product by vacuum filtration and air dry.13) Determine the mass and melting range of the final product.14) Calculate the percent yield of product obtained. Compare the melting range of the productto that listed in the literature.15) Turn in your product for evaluation.52

According to the question we have, The number of moles of bibenzyl is given by = 1.4 mmol = 0.0014…

Answered: Lab on the Radical Bromination of a…

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...