In the multistep synthesis of diphenylacetylene from stilbene experiment, what i
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Question
In the multistep synthesis of diphenylacetylene from stilbene experiment, what is the importance of adjusting the table of reagents for procedure 2 based on yields in procedure 1? What does 85% KaOH mean? What is the purpose of this experiment?
HBr3 purpose are apfly named "bomb readtors" because of the possibility for acatastrophic explosion Br Br C3 120 160-170°C Please regenerate this table in your metebook filling in any of the blanks Reagent stibrbromide 85% solid potassium hydraxide dibromide Values stilbene Pyridinium formula C14H12 CSHsBr3N C14H12Br2 1.0 expected 1.0 KOH C14Hio equiv 1.0 expected 200 mg 400 mg In general the rate of reaction doubles for every 10 °C rise in temperature moss 200 mg 100 mg 1.11 1.25 mmol 1.11 mmol Quiz ideas 0.588 mmol 1.49 mmol 0.588 mmol melting 124 °C What is a chemical test for the pres- ence of an alkene? 236-237 C 59-61 °C bolling boiding solids 170 *C 19 mm Hg Give a GC quiz for computing % yield. solids solids Calculate the molarity of the starting material in acetic acid. Glassware Set-up Procedure l: To a clean 5 mL conical vial, equipped with a spin vane, is added (E)-stilbene (200 mg) and acetic acid (3 mL). A reflux con denser and a drying tube is attached and the mixture is heated to 120- 130°C until a homogenous solution forms. The drying tube is removed and, while stirring, pyridinium perbromide (400 mg) is added throughIR and C and H NMR the differences Why was sulfolene used in the pre- ceding experiment rather than buta- diene? cidiegenpriment rather than buta- Describe the differences in the MS, between cyclohexenone and cyclo-Explanation / Answer
Questions:
Q1. What is the importance of adjusting the table of reagents for procedure 2 based on yields in procedure 1?
The process done in procedure "2" depends on the yield of procuedure 1. Therefore, if a low yield is achieved in procedure "1", the materials must be adjusted and vice versa for high yields. It is important, because if it is not adjusted then the reaction will no be achieved as desired.
It is important to read in the lab description, that we are working with liquids and solids. We will crystalize solids (the product, most likely)ñ.
Note that Hexaphenylbenzene is the final product (the desired one) and it comes from the first reaction
Q2. What does 85% KaOH mean?
KaOH solids/pellets are not 100% KaOH; they are mixed with other materials (inerts). The 85% shows the purity of KaOH in the sample by mass.
Q3. What is the purpose of this experiment?
Besides learning how to operate lab equipment and operation. It seems that the main point of the lab experiment is to convert a double bond (from stylbene) to a triple bond (Diphenylacetylene) via halogenation/dehalogenation
The lab experiment also shows operations such as reaction/purification
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