Obtain 5g of powdered nutmeg and place it in a 100 mL beaker. Add 15 mL of aceto
ID: 507458 • Letter: O
Question
Obtain 5g of powdered nutmeg and place it in a 100 mL beaker. Add 15 mL of acetone and a boiling chip. Mix well with your stirring rod while heating near boiling on the hot plate for five minutes. Let the nutmeg residue settle. Fit your narrow stem funnel with fluted filter paper. Clamp the funnel over a 50 mL beaker and filter the acetone extract into the beaker. Extract the ground nutmeg once more with 15 mL of fresh acetone. Filter again into the same 50 mL beaker to make a combined extract. Label the beaker "nutmeg extract" and write your names on the label. Carefully place the uncovered beaker on the tray in the supplies hood. By the next lab period, the acetone will evaporate, leaving behind the crude trimyristin. To the dried, impure extract, add 10 mL ethanol. Heat to boiling on the hot plate and then remove the beaker and place it on the bench top. As the solution cools, purified product should crystallize. Filter the product using a Buchner funnel air dry the crystals weigh them. Allow the crystals to dry in your drawer, then record the melting point and IR spectrum during the next class period. Hand in a baggie containing the purified trimyristin. The label should contain your names, the name of the compound, the weight, and the melting point. Your notebook should contain the usual write up, including weight of purified product, IR (including identity of major bands between 1500-4000 cm^-1), mp, and % of nutmeg isolated as purified trimyristin. Also, answer the questions below. Explain how the process of recrystallization works. Why was ethanol used in this step? A student gathers the melting point of a white solid that she believes to be trimyristin. The melting point is 49 degree C-56 degree C. What can you conclude from this? Assume that you carefully purified phenanthrene from a very long, complicated procedure. It took days. It is very important for you to hand the purified enanthrene took days. It is very important for you to hand the purified phenanthrene in to your TA in hour to get a good grade. Oops! You accidentally put the phenanthrene into a vial which you thought was clean, but instead had a lot of Nacl clinging to the sides. What can you do t quickly purify the phenanthrene again?Explanation / Answer
1. Recrystallization is used to purify a chemical compound generally after its synthesis or extraction. A solvent is used such that either the chemical product or impurities in it are soluble in either cold or hot solvent. Complex molecular structures like triglycerides or fats - trimyristin can be extracted from ground nutmeg with acetone or ether. Trimyristim is White yellow greyish solid that is insoluble in water and soluble in ethanol, ether. hence the use of ethanol.
Melting point range of trimyristin is 56 - 57 degrees and theres difference in mp range got frm above experiment and actual one. Due to impurities melting point can be lower. If first crystallisation some acetone remains or in recrystallisation crystals not dried properly.also Colour of final product obtained by this method is white. It should be yellowish white, if the yield of crude product obtained is also less experiment needs to be corrected .
Phenanthrene is soluble in organic solvents while Nacl in water. Just by adding water and organic solvent like benzene and shaking, allow the separate layers to settle discard the Nacl layer and drying the organic layer containing phenanthrene in desicator.
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