"Effect of caffeine on daphnia" Essays and Research Papers

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    In this lab‚ caffeine was extracted from black tea‚ and green tea through a vacuum filtration‚ and a rotovap. The melting point of the sample of black tea was 219.12-236.05 ˚c‚ and for the green tea it was 176.22-227.6 ˚c. The % error of the melting point indicates how much error there was from the melting point taken experimentally. The % error of the melting point for black tea was 0.44%‚ and for green tea it is 3.15%.Since the theoretical melting point of caffeine is between 235-237 ˚c‚ we can

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    Extraction of Caffeine from Tea Leaves Santos‚ Raphael‚ Samson‚ Nonia Carla‚ *Tabora‚ Brylle‚ Tan‚ Kate Michal Department of Biological Sciences‚ University of Santo Tomas‚ Manila‚ Philippines Abstract Tea leaves are natural products that are harvested from agriculture. Caffeine‚ on the other hand‚ is a stimulant that has been shown to speed up the time of reaction‚ increase alertness‚ and improve one’s concentration. What we did in this experiment was to extract the alkaloid caffeine content from

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    Extraction of Caffeine from Tealeaves Perez‚ Albert Solomon K.*; Quiambao‚ Marie Angela C;.Pascua‚ Hanna Harriette R.; Patricio‚ Maria Roxanne DC.; 2-Chemistry‚ Department of Chemistry‚ College of Science University of Santo Tomas España St.‚ 1015‚ Manila Abstract Caffeine is soluble in both water and organic solvents‚ solid-liquid extraction and liquid-liquid extraction were used in the experimentation process. Caffeine was extracted using hot water‚ however‚ due to its

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    Extraction of Caffeine from Lipton® Tea Leaves Nathaniel Camangon*‚ Kaila Bumagat‚ Franz Mari Burgos‚ Remigio Callanta Department of Chemistry‚ College of Science‚ University of Santo Tomas‚ Manila‚ Philippines Abstract This experiment mainly focuses on the extraction of pure caffeine by multiple extraction from commercially acquired tea leaves and determining its purity by melting point determination. A 0.02% yield of pure caffeine was obtained from 10.4978g of tea leaves (4 tea bags).

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    of alkaloid caffeine from tea leaves Date Submitted: September 3‚ 2014 Abstract Caffeine is one of the main constituents of tea leaves. In this experiment‚ 0.0039 g of pure caffeine was isolated from tea leaves. This was done through solid-liquid extraction followed by multiple liquid-liquid extraction. Then crude material obtained was then purified by sublimation. The isolated caffeine was subjected to thin layer chromatography (TLC) together with a standard caffeine. The Rf value

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    This I Believe I believe in caffeine. I believe in caffeine because it keeps me alert‚ not quite awake‚ but alert. After a full night of studying‚ cramming on procrastinated homework‚ or just refusing to go to sleep‚ caffeine keeps you alert enough to be aware of the happenings of your day. But why would a 17 year old girl believe in caffeine‚ a chemical usually depended upon by truck drivers and stressed out adults working a daily 9-5? This is because of a 17 year old girl’s awareness of the

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    the extraction of caffeine from tea leaves to determine its % caffeine. The extraction process selectively dissolves one or more compounds in a mixture into an appropriate solvent. In this experiment‚ it was visible in the process wherein the components of the tea leaves were dissolved in two solvents‚ water and dichloromethane (DCM)‚ with DCM used for multiple extractions. The organic layer was evaporated and the determined % caffeine was 0.12%. Furthermore‚ the purified caffeine was subjected to

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    Experiment 11b: Isolation of Caffeine from a Tea Bag October 12‚2012 Purpose: The objective of this experiment is to extract caffeine from tea bags using the method of extraction. After the caffeine is extracted it is then compared to the nutritional facts amount per serving on the tea bags box. Supplies: Glassware: 1. 50.0 m L graduated cylinder 2. 150.0 mL beaker 3. 2-glass stirring rod 4. 6-test tubes 5. 2-glass pipettes 6. 2-50.0 mL Erlenmeyer flasks 7. glass funnel Hardware:

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    Extraction of Caffeine from Tea Leaves Department of Biological Sciences‚ College of Science University of Santo Tomas España‚ Manila‚ 1028 ABSTRACT: Caffeine is a white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds‚ leaves‚ and fruit of some plants. It is most commonly consumed by humans in infusions extracted from the seed of the coffee plant and the leaves of the tea bush‚ as well as from various foods and drinks containing

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    Extraction of Caffeine from Lipton Yellow Label Teal Leaves Arlie Bamiano‚ Jealine Bernabe‚ Petrenne Caimbon*‚ Jhia Caso Department of Biology‚ University of Santo Tomas Abstract In order to extract pure caffeine from Lipton Yellow Label tea leaves‚ several extractions and phase transition techniques were employed to 6.5029 grams of sample. Initially‚ the tea leaves were boiled in water to extract tea from the leaves (Solid-Liquid Extraction). After extracting the tea‚ several steps of

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