In this week's experiment, you will isolate the biodiesel from the synthesis you started last week. You will compare your biodiesel to other fuels, including conventional diesel and commercial biodiesel, by measuring their viscosity. Lastly, you will analyze the results of the ecotoxicity assay from last week's experiment.
There should be two layers present in the centrifuge tube containing your reaction from last week. You will identify which layer contains biodiesel and which layer contains glycerol. The glycerol layer will be removed and used in part 3. The biodiesel will be purified by adding a drying agent to remove any remaining glycerol, water or similar contaminants, then filtered to separate the biodiesel from the drying agent.
You will view the radish seed images that correspond to your assigned fuel from last week. Using these images, you will determine the toxicity of your fuel and compare your results to those obtained by your classmates.
You will investigate the viscosity of several fuels by measuring their flow rates through a glass pipet.