Ramos and Kristina Todorovic Chemistry 203 DEN Dr. Mohamed El-Maazawi Part A. Acid-Base Indicators Purpose In this part of the experiment‚ we will find a reagent that will shift the acid-base equilibrium reaction described by Equation (2) in one direction and then a second reagent that will cause the equilibrium position to shift back in the opposite direction. Introduction An acid–base indicator is a substance that changes color as the pH of a solution changes
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1: Vitamin C In this experiment we need to determine the wt% of the ascorbic acid in three samples by using direct and back titration. A back titration‚ in which a known excess of one standard reagent is added to analyte. Then‚ the second standard reagent is used to titrate the excess of the first reagent. For this experiment‚ an unmeasured excess of KBrO3 will be added to an acidified solution of the standard potassium bromate till the faint yellow color appears. This excess of bromine can be determined
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Mona Vaidya April 8‚ 2014 Professor Diaz Chem 317 Section: 20711 Lab Experiment: Nitration of Bromobenzene Introduction: The chemical reaction of nitration consists of a nitro group being added to or substituted in a molecule. Nitration can basically be carried out by a mixture of concentrated nitric acid and sulfuric acid; this mixture is useful to obtain the active nitronium ion. Electrophilic aromatic substitution is a method used when a functional group is needed to be substituted on
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anhydride. Acyl esterification is a reaction between acid anhydrides and acyl chlorides. Through this experiment‚ the students that performed it would have learned about reflux‚ extraction‚ washing and drying. The reflux technique is the boiling of the reagents while cooling the vapor escaping from it and having it returned in the flask to prevent evaporation. This guarantees that the temperature in the flask is constant. Extraction‚ washing and drying the resulting chemicals after the reflux technique
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into simple sugars using dilute hydrochloric acid. In hot acidic medium glucose is dehydrated to hydroxymethyl furfural. This compound forms with anthrone a green coloured product with an absorption maximum at 630 nm. MATERIALS 2.5 N HCl Anthrone reagent: Dissolve 200 mg anthrone in 100 ml of ice-cold 95% H2SO4. Prepare fresh before use. Standard glucose: Stock —Dissolve 100 mg in 100 ml water. Working standard— 10 ml of stock diluted to 100 ml with distilled water. Store refrigerated after adding
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Alamar Blue assay are performed to show cell viability and proliferation. In the procedure we treated our cell line‚ SUM 149 cells with different concentrations of an unknown treatment. SUM 149 cells are an inflammatory breast cancer cell line. The treatments were used to suppress cell growth and proliferation. The station that I performed my work was station C. I platted my cells and aloud a previously determined allotted time for cell proliferation and growth to occur. The cells were then treated
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alcohol and an acid. In this case‚ n-butyl alcohol and sulfuric acid were the reagents. There were two methods of distillation that was involved in this experiment. The first was by reflux distillation‚ which is used to speed up a chemical reaction without having the reactants/ products evaporate or explode. Data Table 1 indicates the amount of each reagents that was prepared for the reflux apparatus. However‚ the reagents‚ sodium bromide‚ water‚ and butanol‚ were combined and cooled in an ice bath
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Introduction 10.2.1 Environmental Significance 10.3 Principle 10.4 Materials Required 10.4.1 Apparatus Required 10.4.2 Chemicals Required 10.5 Sample Handling and Preservation 10.5.1 10.6 Precautions Procedure 10.6.1 Preparation of Reagents 10.6.2 Testing of Water Sample 10.7 Calculation 10.7.1 Table 10.7.2 Data Sheet 10.8 Interpretation of Results 10.9 Inference 10.10 Evaluation 10.0 EXPERIMENT ON DETERMINATION OF DISSOLVED OXYGEN PREAMBLE: “How to determine dissolved
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Part A- Preparation of p-Acetotoluidide • After completing the experiment‚ a yield of 0.21 g of a pure white crystal were collected from the Buchner funnel‚ and when compared to the calculated theoretical yield‚ 0.82 g (found in Calculations 1.A)‚ a percent yield of 25.4% can be calculated for this procedure. Although this value may not seem favorable for this procedure‚ when compared to the expected value described by the laboratory manual‚ which was 0.4 g‚ it can be seen that the procedure performed
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oC and allowed for it to grow overnight; the following day we came back to finish our confirmatory test. To do so‚ we added 10 drops of Kovac’s reagent to the tube and watched for a color change. Results: A positive test‚ indicated by a red/pink layer‚ is due to the tryptophan being hydrolyzed producing indole‚ pyruvic acid‚ and ammonia. The Kovac’s reagent indicates solely the presence of indole because the bacteria will use the pyruvic acid and ammonia for nutritional needs. A negative test is indicated
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