Melting Point Of Caffeine Lab Report

First students obtained 8 graduated cylinders and labeled them. Each one contained a different ratio of vinegar and water. These graduated cylinders with the liquid were weighed and recorded.Then, students obtained an Alka-Seltzer tablet and recorded its mass. Then one alka-seltzer tablet was dropped into each of the graduated cylinders. Students had to

Thus, leaving us with a layer of aspirin and another layer of CH2Cl2. During the unknown separation, the aspirator evaporated the the solvent. But by cooling the substance we were able to recover the dichlormethane and then re evaporate until I only saw the solid substance remain. Although we succeeded with losing barely any substance, as I will prove later in the calculations section.

Caffeine is a mild stimulant that occurs naturally in at least 63 plant species. Caffeine can be found in the leaves, stems, seeds, and roots of these various plants. Caffeine is part of the methylxanthine family. It consists of a xanthine molecule with three methyl groups attached to it. Caffeine can be found in many products like sodas, tea, and coffee, but it also occurs in several other products such as prescription medications, diuretics, and pain relievers. Caffeine’s widespread use and popularity have caused many people to view the substance as an addictive drug. Thus making caffeine the most inexpensive and readily available drug known to man. Then on the other hand there are

Components containing caffeine were composed into stock solutions. These solutions were diluted to 1: 10 substance: mobile phase. A stock solution of caffeine was diluted 1:50. A sequence of diluted caffeine solutions were prepared for use as a standard (ppm): 1, 2, 4, and 10. Solutions of acetaminophen, acetylsalicylic acid, and Goody’s Powder were developed to differentiate chromatographic peaks observed. These solutions were subjected to HPLC for examination of the observed peak area and retention time for the set of compounds. Comparison of retention time allowed for the differentiation of peaks observed. The peak area obtained was utilized to determine the relative concentration of caffeine present in Goody’s Powder based on the relationship obtained in the standard. The content of caffeine present in Goody’s Powder by percent weight was identified.

The following procedures and materials were thought up by my partner and me, which was done on a small scale due to lack of time to perform a full fledge experiment that involved a large sample size. Our project consisted of a sample size of ten people in which each subject was given a survey to complete and a consent form to sign stating what the experiment was about. We also expressed with the up most confidence that their scores and identities within this research will be kept confidential. We articulated to each subject to not drink any caffeine four hours prior to the experiment so that we would not have any type of bias. My partner and I obtained ten cups (regular coffee cups) on day 1 and filled each cup with 200ml of water, in which five out of the ten cups had the caffeine pill ( dissolve in water before giving to subject)

Many manufactures release the caffeine content of their products publically, but not always, and new products and flavors are continuously introduced to the market. If quality checks are not performed, manufactures may alter the caffeine and benzoic acid content to suit the demands without public knowledge. To ensure the levels of caffeine and benzoic acid in products do not exceed the established safe limits and to inform the public of the amount of these compounds being consumed, various methods of analysis have been performed. Before the introduction of modern techniques, spectrophotometric methods alone were used to determine concentration of a compound in a mixture.6 The caffeine content in coffee, tea, soft drink, and energy drinks were determined using an immunoassay.7 The caffeine content in mixtures also used to have to be extracted before quantification.8

The next step in this lab is to rinse the Erlenmeyer flask with distilled water down the drain and then repeat the experiment, this time adding 10 ml of 0.10M KI and 10 ml of distilled water to the flask instead. The flask should again be swirling to allow the solution to succumb to the same temperature as the water bath and once it has reached the same temperature, 10 ml of 3% H2O2 must then be added and a stopper must be immediately placed on the flask and recording should then begin for experiment two. After recording the times, the Erlenmeyer flask must then be rinsed again with distilled water down the drain. After rinsing the flask, the last part of the lab can now be performed. Experiment three is performed the same way, but instead, 20 ml of 0.10 ml M KI and 5 ml of distilled water will be added and after the swirling of the flask, 5 ml of 3% H2O2 will be added. After the times have been recorded, data collection should now be complete.

11. The experiment was repeated three more times using different water temperatures (room temp water, cold temp water, hot temp water).

The start of the experiment consisted of filling up four beakers with de-ionized water to 150 ml. After the beakers were filled to the appropriate amounts they were then labeled with the

To prepared 1X TEA solution, 2ml from the final solution of the 50X TEA puffer was added to 98 ml of DW.

There were several steps completed to prepare for the experiment. Three dialysis tubes were filled with approximately the same volume of distilled water and then were tied shut. The initial mass (in grams) of the tubes was taken using a triple beam scale. I then filled three 500 mL beakers with 400 mL of water each and dissolved different masses of solute (table sugar) in each beaker in order to make 5%, 10%, and 20% solutions. The beakers were labeled accordingly, and then 20 g, 40 g, and 80 g (respectively) of table sugar was weighed out using a digital scale and placed into the corresponding beakers. The sugar was stirred in using a stirring rod until all of the solute was completely dissolved.

(7)When data is complete, multiply number of each liquid by 2 to get the correct number of heartbeats per minute.

Then, each group of students received the necessary materials to complete the experiment. When the students received the cups, they labeled cups to distinguish between the salt solution, distilled water, and control group. After weighing the cups and finding the mass of the cucumbers, the students poured 50 ml of water in one cup, 50 ml of salt solution in the other, and left the control cup empty. Then, the students placed the cucumbers into the cups and waited 30 minutes for the results. After the 30 minutes, the students removed the cucumbers from each solution and dried the cucumbers with paper towels. The students then weighed the cucumbers again and recorded their results. Lastly, the students found the difference from the original mass of the cucumbers and recorded their results.

Throughout the experiment I felt that there were many things that could have been improved on, so if I were to do the investigation with the modifications, I would get the correct and accurate results. Firstly the syringes that we were using to measure the liquids were not very accurate because, it did not have the lines between the whole numbers, therefore forcing us to guess the amount that was needed. A more precise piece of equipment would be needed instead such as a burette, if this experiment was done on a larger scale this would be more efficient, and accurate. Another limitation with the experiment was that there was not enough DCPIP, thus limiting the amount of repeats being

Step 1 and 2 was repeated by using distilled water by replacing the test solution.