Extraction of Caffeine with Solvents

EXPERIMENT 9: EXTRACTION WITH SOLVENTS PG. 115 120, SEC. D launching The purpose of this lab is to bow out caffein from tea leaf using the same proficiency use in the old lab. More specific on the wholey, this lab tortuous a mixture from which a single chemical demand to be recovered from a mixture whose contents were unknown. victory of this technique was measured by finding the recovered big money of caffeine. Procedure In a 500-mL Erlenmeyer flask, place 30 g of quotidian alter tea, 300 mL of water, and 15 g of pulverize calcium carbonate. After boiling the mixture gently for 20 min, on occasion swirling it, kick in 5 g of Celite or former(a) permeate aid, separate the hot mixture in a Buchner funnel, and press the filter cake firmly with a large-mouthed cork to obtain as much of the liquid as possible. Cool the aqueous draw up to 15-20C, transfer it to a separatory funnel, and extract the caffeine with four consequent 25-mL portions of dichlorometha ne. Transfer the extracts to a simple-distillation aggregation and distill off all but 10 mLof the reroot on a go toilet. Save the recovered solvent. melt down the combined solutions to graveness on a steam clean or hot-water bath in a hood.

To purify the jumpy product, dissolve it in about 5 mL of acetone by warming the mixture on a steam bath; add dropwise just enough miscellaneous hexanes to loose the warmed solution faintly cloudy; then consent to the solution to chill and allow the product to crystallize. Collect the greenness-tinged crystals on a polished vacuum filter and wash them with a litt le mixed hexanes. The melting point of caffe! ine inform in the literature is 236°. This is too high to be safely determined in an apparatus using a mineral-oil bath. The green color of the caffeine sample can be remote by sublimation. circuit board of Chemicals Chemical| Quantity| MW| bp, °C| mp, °C| Density| caffeine| -| 194| -| 236| -| Results Chemical| Yield (g)| Caffeine| 0.144| 14 tea bags were used in this experiment. Based...If you want to get a full essay, pose it on our website: BestEssayCheap.com

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