PROCEDURE Weigh out 10 g of ground nutmeg and place it in a 500 mL round bottom

Question

PROCEDURE Weigh out 10 g of ground nutmeg and place it in a 500 mL round bottom flask. Add 90 mL of hexane and a few boiling chips and set up an apparatus for reflux (see the figure in the apparatus appendix). Reflux the hexane-nutmeg mixture for 30 minutes using a heating mantle and variac set at -80% to start then reduce to 50-60% to maintain reflux (see Safety: above). Determine the mass of your clean, dry 250 mL round bottom flask, containing a few boiling stones. Remove the mixture from the heating mantle and while it is still warm, filter off the residue of the nutmeg by gravity filtration, collecting the filtrate in the preweighed 250 mL round bottom flask. Rinse out the flask in which you did the original extraction (i.e. the 500 mL flask) with about 5-10 mL of fresh hexane and filter the washings into the 250 mL flask. Dispose of the filter paper in the dump in the fume hood. Set up the apparatus for simple distillation (see the figure in the apparatus appendix) and distil off the hexane using a heating mantle and variac set at ~70% then reduce to 50%. Record the temperature (to the nearest 0.1 °C) when the first drop of distillate is collected in the collection flask and record the highest temperature reached during the distillation. This will be the collection range for the distillation. Continue heating until the last of the hexane has distilled over. Dismantle the distillation set-up and dispose of the distilled hexane in the appropriate dump in the fume hood (make sure you know which flask contains the hexane). Remove the flask containing the crude product and weigh the flask. Record the mass of crude product. At this point, the sample likely contains a trace of hexane and will therefore show an artificially high mass. Leave the flask containing the crude product in your locker for a week (uncorked). After the product has dried for a week, determine the mass of the flask. Record the mass. Store this round bottom flask in your locker until it is purified in the next lab period. NOTE 1 The following procedure can be used to clean the round bottom flasks used in this experiment. The product is not soluble in water and not easily dissolved in cold organic solvents. To remove the remaining traces of crude product, you will need to use soap and HOT water (scrub with a brush). Then use water to rinse out al of the soap. To remove the water from the flask, rinse it with two small portions (2-3 mL) of acetone by placing the tip of the acetone squeeze bottle in the neck of the flask and allowing the acetone to run down the inside. Rotating the flask while adding the acetone will help rinse any water droplets off the side of the flask. The flask can be swirled then the acetone poured out into the general organic dump in the fumehood. Let the flask air dry for a few moments and if the flask is still not dry, repeat the above procedure. Drawing air through the glassware, by means of the aspirator or by holding the piece of glassware over the window vent, will speed the drying process.

Explanation / Answer

Separation techniques

Filtration

1. After the reflux, the mixture is filtered to remove the solid residue. The filtration is always performed while the solution is still warm as under warm conditions the compound is in the dissolved state in the solution whereas, the solid impurities remain in the undissolved state. If cooled the compound would also come out of the solution and we would loose the material and lower yields would thus be obtained for the reaction.

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