Zinc Sulfamate Lab Report

The product was then suspended in 2 ml of water with a stir rod in a 50 ml Erlenmeyer flask and heated to boiling. Water was added in one milliliter increments until all the product was dissolved (18 ml added total). The saturated solution was allowed to slowly cool, and gradual white crystal formation was observed. Recrystallized product was collected once more by suction filtration with the Hirsch funnel once crystallization ceased. Collected product dried on a watch glass for a week, weighed 0.14 g (1.2 mmol), and the melting point was 139°-141°

The stilbene dibromide precipitated immediately as small plates. The mixture was cooled under tap water helping crystals form. The mixture was cooled before collecting the product by a vacuum filtration. For the crystals not to stick in the flask, the solution was washed with small amounts of ice cold methanol. When done pouring, the isolated solid dried for a few minutes in the filtration. To increase drying time, the crystals were pressed down. When the solid was collected, data such as melting point, percent yield and infrared spectroscopy spectrum values were collected.

The product obtained had a melting point of approximately 107 °C and a weight of .324 grams. Some of the product would not dissolve in water and so was removed through vacuum filtration, which left .141 g not dissolved in solution. It took 13.2 mL of sodium hydroxide to turn the solution of the product dissolved in water pink. A molecular weight of 138.63 g/mol was calculated from the data. These results indicate that the product was 2-methylbenzoic acid, the Grignard reagent was 2-methylphenylmagnesium bromide, and the unknown bromide solution was 2-methylbromobenzene. Calculations showed that the limiting reagent of the Grignard preparation was magnesium and that the experiment had a 23.13 % yield.

The mixture was transferred to an ice bath to crystallize the product, after which the product was collected by vacuum filtration on a Hirsch funnel, washing the flask with small aliquots of cold xylene and pouring the solution over the crystals, allowing the vacuum to thoroughly dry the product. Additional drying was achieved by transferring the product to filter paper and pressing the crystals to remove any excess moisture. The product was then weighed and a melting point determined. A comparative TLC was run in Hexanes:Ethyl Acetate solvent against maleic anhydride to verify the purity of the

Experiment 55 consists of devising a separation and purification scheme for a three component mixture. The overall objective is to isolate in pure form two of the three compounds. This was done using extraction, solubility, crystallization and vacuum filtration. The experiment was carried out two times, both of which were successful.

The week after, a recrystallization was performed on the previous week’s crude product. The product ethereal solution was first heated on a steam bath until dry. During the heating, a beaker of methanol was collected and also placed on the steam bath. Once the product was dry, it was cooled to room temperature and then placed in an ice-water bath. The now boiling methanol was added to the crude crystals and a recrystallization was performed. Once completed, the now purified product was collected via Buchner vacuum filtration and stored in drawer to dry for a week. Afterwards, a melting point range of the purified product was obtained by using a Mel-temp apparatus. Lastly, an

Abstract: One mixture of two unknown liquid compounds and one mixture of two unknown solid compounds were separated, isolated, purified, and characterized by boiling point. Two liquid unknowns were separated, isolated, and purified via simple distillation. Then, the process of an acid-base extraction and washing were used to separate two unknown compounds into two crude compounds: an organic acid and a neutral organic compound. Each crude compound was purified by recrystallization, resulting in a carboxylic acid (RCO2H) and a pure organic compound (RZ). The resulting mass of the pure carboxylic acid was 1.688g with a percent recovery of 31.80%, the boiling range was 244-245 °C, and its density was 2.0879g/mL. The resulting mass of the pure organic solid was 2.4902g with a percent recovery of 46.91%, the boiling range was 52.0-53.4°C, and its density was 1.5956 g/mL.

This gave percent yields of 91.1% and 89.6%. These high percent yields and melting points indicate that the extraction and recrystallization performed in this experiment were successful. Introduction

In this experiment, the scientists are testing which amount of zinc mossy would make a few normal cleaned pennies change their colors into silver when they are placed in the boiling solution of zinc sulfate and water and then turn their colors into the brightest yellow (gold) when they are exposed directly to heat,. The independent variables in this experiment are the amount of zinc and zinc sulfate measured in gram and the dependent variables is the shades of yellow (compared in decimal R,G, B code) of the penny after all steps of the experiment. The constant of this experiment will be the temperature of the tap water used to boil the solution, which is 100°C and the temperature of the hot plate used to heat up the silver penny, which is about 300°C. And the controlled of this experiment is the pennies with the brownish color.

The IR spectrum attained also contained a slightly broad stretch between 3200-3600 cm-1, this could be indicative of a phenol group present or an alcohol impurity. One theory to this impurity may be due to a dirty salt plate used during the spectra reading. Alcohol residue could be remaining on the plate from previous laboratory experiments.

The product obtained had a melting point of approximately 128-130 °C and a weight of .054 grams. The limiting reagent was calculated to be sodium borohydride. With the weight and limiting reagent, the percent yield was calculated to be approximately 53.33%. The IR of the product showed a peak at approximately 3311.25, which indicates the presence of an O-H bond.

Once cooled, the mixture was then transferred to a separatory funnel using the funnel while avoiding adding the boiling chip. 10 ml of water was then added to the mixture. The mixture was gently shaken and the phases were allowed to separate. The funnel was then unstopped and the lower aqueous phase was drained into a beaker. 5 ml of 5% aqueous NaHCO3 was added and then shaken gently. A great deal of caution was taken into consideration because of the production of carbon dioxide gas which caused pressure to develop inside the funnel. The pressure needed to be released so the funnel was vented frequently. The phases were allowed to separate and the lower aqueous phases was drained into the beaker. After draining, 5 ml of saturated NaCl was added to the funnel and then shaken gently. Once again, the phases were allowed to separate and the lower aqueous phase was drained into a beaker. An ester product was produced and was transferred into a 25 ml Erlenmeyer flask. This organic product was then dried over anhydrous Na2SO4 to trap small amounts of water in its crystal lattices thus removing it from the product. Finally the ester was decanted, so that the drying agent was excluded from the final product.

Discussion The percent yield for this reaction was 8.9%. The theoretical yield for this experiment was 5.95 g, but the actual amount obtained was 0.53 g benzocaine. The percent yield was very low due to inorganic impurities from Na2SO4. These impurities also affected the melting point of the product received.

To characterize the synthesized product using its boiling point, results of simple chemical tests and derivatization reactions, along with the determination of the melting points of the hydrazones and comparison of the hydrazones using their RGB values.

2. (5 pts) List and explain the names and affiliations of the various characters/stakeholders in this story – I’m looking for us to use the story to map out the complexities that are generally associated with solving public health puzzles – the stakeholders you list and explain here should apply to many of the cases we consider going forward.