Dichlorometry Lab

We had performed two different parts to the experiment within a two day process and created a second objective. Our second objective was to separate a mixture by specifically using the filtration method. Before starting the experiment it is important to wear the appropriate protective gear such as goggles, gloves, and a lab coat. This will prevent injury to self or others. For the first experiment, the following materials were necessary:

We made sure the solution is strongly acidic by testing it with litmus paper getting a pH of 2. We then cooled the mixture to room temperature swirling the flask occasionally in an ice bath. We collected the aspirin by vacuum filtration and washed the aspirin on the filter with cold distilled water. We let it air dry for 30-35 minutes and then weighed the aspirin. It weighed out at 0.513g. The unknown component was calculated and weighed at 0.738g.

The pipette was used to transfer 8 mL of the 0.5 molarity solution into the graduated cylinder. Distilled water was added to raise the bottom of the meniscus to the 20.0 mL line and the solution was transferred into the beaker after it was rinsed with the solution. The pipette was used to take a small quantity of the solution and rinse and then fill a test tube with the solution. The amount of 0.2 molarity solution needed to create 20.0 mL of 0.1 molarity solution was calculated as 10.0 mL. The pipette was used to transfer 10.0 mL of 0.2 molarity solution into the graduated cylinder and distilled water added until the bottom of the meniscus reached the 20.0 mL line. The solution was transferred to the rinsed beaker and then a portion placed into a test tube that had been rinsed with the solution. The amount of 0.1 molarity solution required to create 20.0 mL of 0.05 molarity solution was calculated to be 10.0 mL. The pipette was used to transfer 10.0 mL of 0.2 molarity solution into the graduated cylinder and distilled water added until the bottom of the meniscus reached the 20.0 mL line. The solution was then placed into a beaker that had been rinsed with the solution and then into a rinsed test

In a test tube, 0.5mL of the sample will be added with 0.5 mL of water and shaken vigorously. Take note for its solubility by parts (0.5mL is one part). Keep adding parts of the solvent until the sample is soluble. If not, add until ten parts of the solvent and determine its solubility. To separate test tubes, water will be replaced with ethanol, chloroform, ether, and acetone as solvents. Same procedures were

349mg of solid acetaminophen was weighed and placed into a 5mL conical vial with a triangular spin vane, point facing downward. Next, 2.6mL of 1M NaOH were added to the same vial. An air condenser was attached to the vial; both were clamped to a stability rod above a hot plate. An aluminum block was placed onto the hot plate stabilize the vial. A small thermometer was placed in the same aluminum block. The solution was heated gently and simultaneously stirred for 10 minutes until all solid was dissolved in the solution. The conical vial was removed from heat set aside to cool. Next, 0.3mL Ethyl iodide was added through the top of the condenser using a Pasteur pipet. The solution was once again heated but this time using the reflux technique.

Carefully drain the lower layer into a 125 mL Erlenmeyer flask, and then add magnesium sulfate to the flask to assure no water got in. Magnesium sulfate will form clumps if water is present, the clump can then be gravity filtered, the excess solution is then placed in the rotary evaporator to evaporate the DCM, leaving behind crude caffeine. Then in a group of six, everyone's crude was put in a pre-weighed Petri dish and purified using

Before beginning our investigation, we gathered our materials, which were: a pipette, pipette bulb, burette. To neutralize the reaction of the unknown concentration, called the analyte, we had to determine the the volume of one reactant of known concentration, known as the titrant. The titrant,which was the base, (hydrochloric acid), was added little by little into the burette until color of the analyte, (purple), was reached. The change in color was determined using a

As previously said, the experiment was about finding out chemical components in Tylenol and Anacin, the task was to find which of those compound contains acetaminophen and acetylsalicylic acid. Two tablet of Tylenol and Anacin were given and crushed in two different mortar and pestle in order to avoid cross contamination. When taking a sample of both compound out of mortar, two very clean spatula were used to put the powder in the test tube and then added 2.5 ml in each test tube of 50/50 mixture of ethanol and methylene chloride solvents. The mixture were stirred by using a clean glass rod for few minutes to get a well dissolved mixture. In addition to both solution already made, two more compounds were provided: acetaminophen and acetylsalicylic

10 mL was accounted for the first fraction, 7 ml for the next and the last 5 ml was accounted for the last fraction (Landrie 45). Therefore, after each fraction, the distillate was transferred into a beaker and at the end of the experiment there were three beakers (Landrie 45). These three beakers were used for gas chromatography (Landrie

The experiment was started preparing 300 mL of a 2 M HCl solution. A graduated cylinder was used to collect 200 ml of deionized H2O, then it was added to an empty 600 mL beaker which was designated to be the 2 M HCl solution. 100 mL of 6M HCl was then added to a sanitized graduated cylinder and poured into the 600 mL beaker with H2O. The solution was then stirred with the glass rod. 150 mL of a 2 M NaOH solution was then prepared. 50 mL of deionized H2O was added to a 400 mL beaker. Then, a graduated cylinder of 100 mL 3 M NaOH was added to the beaker. Repeat stirring. LabQuest was then configured and setup for data collection of Part A; the interval box should be set to 15 seconds.

The liquid was then collected and labeled “Wash” 300 ul of elution buffer was then added, the liquid was collected and labeled “Elute 1”. This step was repeated twice while collected the excess and labeling “Elute 2” and “Elute 3”. Once the last elution ran though the bottom of the tub was capped. 300 ul of elution buffer was added and mixed in with beads to make slurry; the excess was collected and labeled “beads”. The presence of GFP was then checked by using a UV light, after checking for GFP the tubes were placed in a 4 degree Celsius refrigerator.

The objective of experiment 6 was to learn how to separate an unknown mixture by gas chromatography in order to analyze the data about the unknown compounds in the mixture. The objective of experiment 7 was to utilize a thin-layer chromatography to test the purity and contents of each vial from the previous experiment. Introduction

The purpose of this lab was to calculate the mass percent of ASA in a tablet of aspirin. After conducting the experiment, the molarities of the each diluted ASA solution were calculated. Then, the slope of the Beer’s Law plot was determined by graphing the DS molarities and absorbances. That slope is then used to calculate the concentration of ASA in the diluted aspirin solutions. From the concentrations, the mass of ASA is then calculated; the average mass being 0.343 g. The average percent of ASA in the tablet is 92.7%. Most of the aspirin tablet consist of ASA. An error that could have came from pipetting the diluted solutions into the flasks. It is very easy to accidentally over pipet the amount needed. Once the solution goes into the volumetric

Reagent MW (g/mol) Amount used (g) Moles used Salicylic acid 138.12 0.1101 7.914 x 10 Acetic acid 60.05 0.27 4.5 x 10 Table 2: yield of product, Aspirin Substance Weight (g) Aspirin in vial 0.0958 Aspirin residue on filtration disc 0.0011 TOTAL Asprin yield 0.0969 Yield percentage of Asprin 68.0% Table 3: Observations on the activity of Aspirin Test Tube Content of Test Tube Observations made #1 10 mg salicylic acid 1 drop 1% FeCl¬3 solution 1 ml water Solution turned purple, remained clear No odor detected

When measuring out the substances for this experiment, an individual could get random errors when slightly different values are collected each time they perform the measurement. Systematic errors, on the other hand, are more difficult to detect but can be avoided if an individual looks for them with care. A systematic error can occur in this experiment if the chemicals that are used are expired or when the scales that are being used have been tampered with beforehand. Aside from random and systematic errors, there are a few limitations in the design of this experiment. The use of small graduated cylinders can provide inaccurate results for the experiment. Since the smaller cylinders can only hold a small amount of acid, there is a possibility that the solutions can undergo supersaturation, when a solution contains more of the dissolved material than could be dissolved by the solvent. In a case that this happens, it would be difficult to predict when the tablet stop dissolving in the solution. Therefore, due to the number of errors that could be made in this experiment, the results are a little unreliable unless changes are made during the procedure and design of the lab set