After a series of washes to remove any impurities, the compound was dried and decanted, cholesterol was synthesized. Melting points were obtained from commercial cholesterol, dibromocholesterol, and synthesized cholesterol using the Fisher-John Melting Point Apparatus. A TLC plate was completed, spotting commercial cholesterol, dibromocholesterol, and synthesized cholesterol. The silica gel was used as the stationary phase and the ethyl acetate: hexane (30:70) was used as the mobile phase. The silver nitrate test was conducted to test for the functional group of 2°and 3° alkyl halides as positive and negative controls were used.
A binding material can be separated by dissolving the tablet in ether since three active ingredients are soluble. Then, aqueous K2HPO4 and KOH are used to extract the ether solution with the conjugate base of the Aspirin layer and the conjugate base of the Acetaminophen, respectively. The caffeine can be isolated from the left over layer by evaporating the ether. Two separated solutions form solid by acidifying with HCl and the solid residue can be collected by vacuum filtration. According to the Revell's lab experiment, aspirin, acetaminophen, caffeine recoveries are 60% or higher, <10% and <5%, respectively.
Results : Yield (mass in gram) = __________________0.128 g_____________________ Melting point of pure phenyl benzoate (OC) = ___________70O______________ Melting point of your phenyl benzoate (OC) = ___________69O______________ Questions : 1. Why do we use NaOH solution to dissolve phenol rather than water in step 1 ? Because NaOH can be use to change the phenol to ion form, which can be more soluble in the aqueous
Radu Purtuc | Chemistry 231 - Lab | Section 32 Ronnie :: team-member TECH 705, SEPARATING ACIDS AND NEUTRAL COMPOUNDS BY SOLVENT EXTRACTION - MACROSCALE EXTRACTION July 6, 2006 Lab Report INTRODUCTION Purpose: using extraction technique to separate acetanilide, p-toluic acid, and p-tert-butylphenol; then measure the melting points of each compound and comparing them to the statistical values. Background: separating acids and neutral compounds by solvent extraction is a useful technique used in practice by chemists to separate organic compounds from mixture of other compounds. It generally involve several steps, with limiting factors being the number and output purity of compounds to be extracted from source mixture. A number of specific compound solvents not inter-miscible are used to separate and dissolve compounds, and a physical transfer between solvents is employed. An example of use is cleaning compounds of impurities, where different solvents work as a molecular filter that interacts differentially with compound and impurities respectively.
b) What is the molar concentration (molarity) of ethanol in the wine? Chem 131 Solution Stoichiometry and Gas Law Problems Page 1 Problem 3 As part of some research for the product Alka-Seltzer, a researcher combines 0.840g sodium bicarbonate with 100.0 mL of 0.0500 M citric acid (H3C6H5O7). a) Write the molecular, complete ionic, and net ionic equations for this reaction (assume that each molecule of citric acid is completely neutralized). b) If the dry gas that the student actually collects occupies a volume of 0.196 L at 25°C and 1.00 atm pressure, what is the percentage yield of this reaction? c) The researcher
This reaction can be summed up using the following formula: 5Fe2++8H++MnO4- →5Fe3++Mn2++4H2O After standardization, the potassium permanganate solution is then titrated with 3 different magnesium oxalate solutions. To find the concentration of the C2O42- the balanced net ionic redox reaction formula is used: 5C2O42-+16H++2MnO4- →10CO2+2Mn2++8H2O It is important to note the addition of sulfuric acid (9M H2SO4) in performing this experiment because of the following reasons: 1) Sulfuric acid keeps the iron (II) from air oxidizing into iron (III) 2) Sulfuric acid keeps the iron (II) from hydrolyzing into Fe(OH)2 3) Sulfuric
| Observations of Chemicals | Zinc Sulfate | Powder of a white solid | Barium Iodide | Powder of a white solid. | Deionized water | Liquid, transparent. | Trial # | BaI2 | ZnSO4 | Theoretical Yield of ZnI2 | Actual Yield | Percent Yield | 1 | .67g | .45g | .499820g | .52g | 104% | 2 | .67g | .45g | .499820g | .52g | 104% | 3 | .66g | .46g | .493117g | .48g | 97% | Calculations for Cost | Double Replacement | Synthesis | 0.48 grams of Zinc Sulfate - $0.02 | 1.00 gram Granular Zinc - $62.50 | 0.67grams of Barium Iodine Dihydrate - $0.886 | 2.00 gram Iodine - ($74.90 × 2) - $149.80 | 0.52 grams of Zinc Iodide - $0.906 | 1.00 gram zinc - $0.212 | 1000 grams of Zinc Iodide = $1,923.00 | 1000 grams of Zinc Ioidide = $212.30 | Focus Question Should chemists prepare Zinc Iodide, from its Elements or from a Double Replacement Reaction between Barium Iodide and Zinc Sulfate?
Results APPEARANCES OF MATERIALS USED Substance Physical Appearance Zinc Carbonate White; powderish Calcium Hydroxide White; powderish; like zinc carbonate 3 M HCL Clear liquid, resembles water 20 mesh granular zinc Grey, metallic, shiny 3% hydrogen peroxide Clear liquid; resembles water Manganese dioxide Very dark grey, black and powdery Copper sulfate Blue, crystalline in structure. Sky blue Zinc iodide Very dark purple, shiny and crystalline in structure 0.1 M acetic acid Clear liquid, resembles water Zinc oxide Very white powdery substance RAW RESULTS Data Specifided (Page 112 CRC handbook) Raw data Volume of Gas Collection Bottle (Average of 3 Trials) 14.04mL Mass of boiling tube (empty) 41.57g Mass of boiling tube with zinc carbonate 43.42g Mass of zinc carbonate 1.75g Volume of water in gas collection bottle after reaction 78.5mL Volume of gas product collected 185.2mL Mass of solid product with boiling tube after reaction 1.11g QUALITATIVE TEST RESULTS Group # Test Observation: Standard Positive/Negative Observation: Experimental Positive/Negative 1 H2 HCL + Zinc bubbling + flaming stick POP! + + flaming splint no POP - 2 CO2 Turned cloudy + Negated from experiment Negated from experiment 3 O2 MgO2 + Hydrogen Peroxide bubbling. Glow stick re-ignited + + wooden splint; glowing stick went out - 4 H2) Added 1 pea size CuSulfate + 1 drop of deionized water; blue, positive + Copper sulfate did not change color when put into wet filter paper - 5 Zn (OH)2 Zinc iodide + 3mL H2O Clear suspension + Visual inspection; cloudy. Acid test= solid + 3M Acetic acid cloudy + 6 ZnO ZnO + Heat yellow Zn Cooled White + ZnCO3 + heat yellow solid.
2-propanol (bp=82 degrees C) 3. tetrahydofuran (bp=65 degrees C) 4. 1-butanol (bp=118 degrees C) 5. butanone (bp=80 degrees C) Give a better separation for the mixture to be distilled tetrahydofuran (bp=65 degrees C) because it is farthest from 100 degrees C Which alkyl halide would react fastest in a nucleophilic substitution using silver nitrate in ethanol (weak nucleophile, protic solvent)? 3-bromo-3-methylpentane (most
h) A way to make hard water softer is to put an sodium nitrate and create a precipitate to mellow out the reaction. Another way of making it softer is by removing the calcium ions one way of doing that is by boiling the solution to take out some of the ions. Conclusion: Overall, we determined that sodium carbonate, Na2CO3, is the anion that can be used to precipitate the most metal cations. Also, we learned that the anion sodium chloride, NaCl, could be used to remove silver ions from solutions. The stuff that I found interesting was that how many colours you can get when you mix the cations and anions