Hello, I need help answering the questions for this experiment, please.
Part A: Microscale Hydration of 2-Ethyl-1-butene Add 2.5 mL of water to a 10-mL round-bottom flask containing a stir bar. Place the flask in a heat block or sand bath at room temperature and carefully add 0.64 g of mercuric acetate with stirring. Stir the mixture until the solid has dissolved. Add 1.0 mL of diethyl ether. Attach a reflux condenser to the flask and adjust the flow of cold water through the condenser. Using a calibrated pipet, measure out 290 μL of 2-ethyl-1- butene in a conical vial and add 1.0 mL of diethyl ether. Use a Pasteur pipet to transfer this solution in small portions to the stirred aqueous solution down through the con- denser. Stir vigorously for 45 minutes. Remove the condenser. Add 1.0 mL of 6 M NaOH to the mixture using a Pasteur pipet, followed by a solution of 0.50 g of sodium borohydride in 2.0 mL of 3 M NaOH. Stir the mixture vigorously for 15 minutes. A mercury precipitate should form at the bottom of the flask. Remove the apparatus from the heat block or sand bath and remove the condenser. Allow the precipitate to settle. Use a Pasteur filter pipet to transfer the supernatant liquid (both layers) to a centrifuge tube. Set aside the mercury and mercuric salts for proper disposal. Transfer the lower aque- ous layer to a second centrifuge tube. Place the diethyl ether layer in a 5-mL conical vial. Add 1 mL of diethyl ether to the aqueous solution in the centrifuge tube. Cap and swirl gen- tly. Carefully remove most of the ether layer and add it to the ether solution in the conical vial. Repeat the extraction with a second portion of 1 mL of diethyl ether. Add the ether layer to the ether solution in the conical vial and add a small portion of anhydrous sodium sulfate. After a few minutes use a Pasteur filter pipet to transfer the solution to a tared 5-mL conical vial containing a boiling chip. If doing IR characterization (below), put a few drops on a salt plate and run the IR spectrum now. Evaporate the diethyl ether using a heat block, a sand bath, or water bath (40â45°C). Weigh the vial to determine the weight of the prod-uct. Keep the vial capped during analysis because the product is volatile.
Characterization for Part A Gas-liquid Chromatography: Using a 10-μL syringe, remove a 1-μL aliquot and inject it onto a moderately polar or polar GC column. One or more peaks may be recorded on the chromatogram including a peak for any remaining solvent and peaks for any remaining starting material and product(s). Authentic samples of potential products (if available) and starting material should be used as standards. Refractive Index: Use a few drops of product to determine the refractive index and apply the appropriate temperature correction. 3-Methyl-3-pentanol has an RI (nD) of 1.419020, and 2-ethyl-1-butanol has an RI (nD) of 1.422020. Infrared Spectroscopy (optional): Transfer 2â3 drops of the diethyl ether solution con- taining the product(s) to a salt plate, and press a second plate against the first to spread out the liquid. Remove the plates from one another briefly and press together a second time. The liquid remaining should now be free or nearly free of diethyl ether. Obtain the IR spec- trum. Compare the spectrum to authentic 3-methyl-3-propanol (a tertiary alcohol) and 2- ethyl-1-butanol (a primary alcohol). 3-Methyl-3-pentanol shows strong C O absorption at 1380, 970, and 900 cmâ1; these bands are not present in 2-ethyl-1-butanol.
Results and Conclusions for Part A
1. Identify each of the peaks by comparison of GC retention times of observed peaks with standards.
2. Measure the areas of the peaks in the chromatogram to calculate the mass percent. The correction factors for the alcohol and the starting alkene are approximately equal.
3. Determine the extent of conversion of 2-ethyl-1-butene to alcohol.
4. Write a detailed mechanism for the formation of the observed product(s). 5. Using your mechanism from above, explain the predominance of the observed product.
