"Purification of caffeine by sublimation" Essays and Research Papers

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    Investigating the effects of Caffeine on the heart rate of Daphnia Shrimp. Aim: In this experiment we are trying to find out how varying the concentration of caffeine can affect the heart rate of Daphnia shrimp. Prediction: I predict that caffeine will increase the heart rate of the shrimp . Introduction: I believe the results will comply with my prediction. Caffeine is a compound found in especially tea and coffee plants and acts as a natural pesticide. Caffeine is a central nervous system

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    A Report of Experiment 1 Purification and Identification of An Unknown Mixture Aim To separate a mixture of a neutral (ester‚ alcohol‚ ketone‚ aldehyde or ether) and an acidic compound (phenol or carboxylic acid) or a neutral and a basic compound (amine)‚ and to identify the unknown mixture by physical (M.P. or B.P.) and spectroscopic methods (NMR‚ IR and MS). Method The mixture (sample number: 27) was dissolved in 200 mL of CH2Cl2 and then extracted with 10% NaOH. The acid was removed

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    The Purity and Purification of Solids- Part 2- Recrystallization Courtney Percival CH 337 Laboratory‚ Section 037 Department of Chemistry Portland State University‚ Portland OR ABSTRACT INTRODUCTION Recrystallization is a commonly used tool in laboratories when dealing with impure solids. "An effective recrystallization is one in which 1) a high degree of purity is achieved as well as 2) a maximum recovery of sample".1 Solubility‚ the tendency of a substance to dissolve in a liquid‚ is an

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    The purpose of this experiment was to isolate and purify cholesterol from egg yolks. Two hard boiled egg yolks were twice extracted with diethyl ether and methanol‚ with the filtrate collected via vacuum filtration. Potassium hydroxide pellets were added to the filtrate‚ the ether was distilled off‚ and the mixture was saponified by reflux. The crude cholesterol was isolated through a series of ether extractions and aqueous washes; then the ether was dried with MgSO4 and removed by rotary evaporation

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    rest of the tests we had to work with other groups so that we could finish off the experiments. Other than some slight mishaps the whole of the experiment including the calculations everything when pretty smooth. Aspirin Synthesising and Purification History of Aspirin The compound‚ from which the active ingredient in Aspirin was first found in salicylic acid‚ was found in the bark of a willow tree in 1763 by Reverend Edmund Stone. The bark from the willow tree contains high levels of Salicin

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    MULTIPLE EXTRACTION OF CAFFEINE FROM DRIED TEA LEAVES USING DICHLOROMETHANE Delos Reyes‚ K.‚ Dizon‚ G.J.‚ Enriquez‚ J.R.‚ Estrada‚ G. and Garcia C. Group 4 2G Med Tech Organic Chemistry Laboratory ABSTRACT Caffeine was extracted from dried tea leaves by multiple extraction technique. 10g of tea leaves was boiled in a solution of 4.4 g anhydrous sodium carbonate and 100ml distilled water and was extracted three times using 20 ml of dichloromethane. Theresidue was collected by decanting

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    My results and the graph indicate that as you add the caffeine to the daphnia‚ the eart rate of the daphnia increases for example the daphnia’s heartbeat is 120 without caffeine‚ however when caffeine is added it is increased to 168. My graph shows a positive correlation and the error bars are also very small which shows that the results have a small range which suggests that my results are accurate and reliable. I think that the experiment was conducted well however there may be some ethical issues

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    of Caffeine Consumption on Academic Performance in College Undergraduates Morgan Bolen‚ Maria Naula-Quintero‚ and Carlin Wright Michigan State University Abstract In this study we are interested in assessing the relationship between average amount of caffeine consumed per day and academic performance. We hypothesized that an increase in average caffeine consumed per day would result in increased academic success. A short survey was composed based on average amount of caffeine consumed

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    Neuropsychiatric effects of caffeine Abstract Psychiatrists rarely enquire about caffeine intake when assessing patients. This may lead to a failure to identify caffeine-related problems and offer appropriate interventions. Excessive caffeine ingestion leads to symptoms that overlap with those of many psychiatric disorders. Caffeine is implicated in the exacerbation of anxiety and sleep disorders‚ and people with eating disorders often misuse it. It antagonises adenosine receptors‚ which may potentiate

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    The effect of caffeine on typing speed‚ accuracy and heart beat 1. Introduction Caffeine is a substance found in coffee‚ tea and most sodas. When it is consumed‚ it is a mild stimulant. The energy drink‚ Monster‚ contains caffeine‚ which has the ability to manipulate adenosine (adrenaline)‚ a substance present in the brain that is used to transmit brain signals to different parts of the body. Adenosine causes an increase in alertness and awareness. Modern studies show that there is direct benefits

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