Extraction of Caffeine with Solvents

EXPERIMENT 9: EXTRACTION WITH SOLVENTS PG. 115 120, SEC. D inst every last(predicate)ation The purpose of this lab is to bow out caffeine from teatime using the same proficiency utilize in the preliminary lab. More specifically, 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 dry out tea, 300 mL of water, and 15 g of pulverize atomic number 20 carbonate. After boiling the mixture gently for 20 min, occasionally swirling it, tag on 5 g of Celite or former(a) separate out aid, filter 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 take away to 15-20C, transfer it to a separatory funnel, and extract the caffeine with four non parallel 25-mL portions of dichloromethane. Transfer the extracts to a simple-distillation aggregation and distill off all but 10 mLof the re beginning on a steamer toilet. Save the recovered solvent. melt down the combined solutions to gravity on a steam lavatory or hot-water bath in a hood.

To purify the jumpy product, dissolve it in about 5 mL of acetone by change the mixture on a steam bath; add dropwise just enough composite 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 lo w vacuum filter and wash them with a little ! mixed hexanes. The melting point of caffeine inform in the lit 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. confuse 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, swan it on our website: BestEssayCheap.com

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