The buffer is removed and rinsed with the electrodes with distilled water. It is then dipped in acetic acid and the pH is recorded. A burette was set up to add the NaOH. 1mL of NaOH is added. The solution is swirled and the pH is measured.
Purpose: The purpose of this lab is to verify Hess’s Law of Additivity of Reaction Enthalpies Chemical Reaction/Physical Reaction: 1.) Na(aq) + OH(aq) -> NaOH(s) 2.) NaOH + HC2H3O2(aq) -> H2O(l) + Na(aq) + C2H3O2 3.) Na(aq) + OH(aq) + HC2H3O2(aq) -> H2O(l) + Na(aq) + C2H3O2 List of Materials:Digital Thermometer, foamed polystyrene cups (3), 250 mL beaker,Weighing boat or small beaker, Graduated cylinders, 100mL(1), 25 mL(2),sodium hydroxide pellets, sodium hydroxide 2.0M, Acetic acid 1.0M and 2.0M. Safety Considerations: Always have safety goggles covering your eyes, do not inhale the fumes of chemicals used.
Fill the calorimeter cup approximately 2/3 with distilled water at room temperature and record the mass in Data Table 1 5. Measure the temperature of the tap water in the calorimeter cup and record in Data Table 2. 6. Carefully transfer the metal to the beaker with boiling water. Boil at least 10 minutes.
Controlled The controlled variables of the experiment were: A. The volume and concentration of the Hydrochloric acid. B. The concentration of the Sodium Hydroxide. Equipment List * Boiling Tube * 10 cm3 1mol dm-3 Hydrochloric Acid (HCL) * 15 cm3 1mol dm-3 Sodium Hydroxide (NaOH) * pH and Temperature Probes * Data Logger * Measuring Cylinder ‘ * Boiling Tube * Teat Pipette Method * Add 10ml of Hydrochloric acid, measured in a measuring cylinder, into a boiling tube.
The graduated cylinder was placed on the scale again (with the added liquid) and the mass was measured in grams to the nearest .01 gram. The graduated cylinder was then placed on the tabletop and the volume was read to the nearest tenth of a milliliter. The liquid was then poured back into the beaker, and the graduated cylinder was thoroughly dried. At Lab Station 2, a dry 10mL graduated cylinder was placed on a balance and the mass was recorded in grams to the nearest .01 gram. Approximately 3mL of Clear Liquid 2 was carefully poured into the graduated cylinder.
LAB REPORT: Hydrolysis of Acetylsalicylic Acid PURPOSE: The purpose of this lab is to become familiar with the identification of ester, carboxylic acid and alcohol functional groups, to understand that formation and hydrolysis of esters are equilibrium processes, to understand how ester hydrolysis yields carboxylic acid and alcohol products, and to understand what a sympathetic ink is and how such inks are visualized. PROCEDURE: 1. Crushed two 325mg aspirin tablets into powder; placed the powder in a 50 or 100mL beaker; added 2 grams of sodium carbonate; then measured and added 20mL of water. 2. Stirred the mixture occasionally; covered it with plastic wrap and allowed to stand overnight in a safe place undisturbed to hydrolyze the aspirin to salicylic acid; noticed the odor of acetic acid in the beaker the following morning.
Laboratory Report: Experiment 1 Standardization of hydrochloric acid by sodium carbonate solution Name: Cheung Chun Hin, Harry Class: 6L (12) Date: 11-9-2009 Objective: To determine the concentration of hydrochloric acid using sodium carbonate solution as a primary standard in volumetric analysis (acid-base titration) Principle of method: The concentration of the hydrochloric acid can be determined by the titration reaction between hydrochloric acid and sodium carbonate solution. Na2CO3 (aq) + 2HCl (aq) H2O (l) + CO2 (g) + 2NaCl (aq) From the above equation, We measure the volume of hydrochloric acid used in the titration (the difference of reading on the burette) and use it in calculating the concentration of hydrochloric acid. So the molarity of the hydrochloric acid Procedures: 1. The mass of anhydrous sodium carbonate required was weighed to prepare 250.0 cm3 of 0.05M sodium carbonate solution. 2.
I then poured the mixture on to a solid white piece of paper. I then used a magnet wrapped in clear plastic bag to separate the iron from the mixture. I weighed the iron and calculated and recorded the mass in table 1. I put the remaining mixture in a beaker with 50 mL of distilled water and heated to a boil and removed, then poured the liquid from the beaker into a paper cup. I then added 15 mL of distilled water and heated to a boil and removed, then poured the liquid from the beaker into the same paper cup that held the previous liquid.
Once all the water from the beaker was gone the clamp was carefully replaced so there were no air bubbles in the tube. The tube connected to the aspirator was then removed and connected to the test tube. The gelatin capsule was placed in the tube before adding 10 mL of HCl that had been measured in a graduated cylinder beforehand. The stopper was quickly and firmly placed into the test tube and the pinch clamp was removed again. After a few minutes the acid dissolved the capsule creating a black foam that then turned into a clear liquid again.
Each organic extract is then dried over anhydrous calcium chloride pellets and evaporated to dryness. The extract is then wet with a minimal amount of dichloromethane and a sample of each is obtained and mixed together with 200 mg of alumina and again evaporated to dryness. This mixture is then placed in the prepared chromatography column and eluted with hexanes until the yellow β-carotene band is collected. The solvent is then switched to a 90/10 mix of hexanes and acetone to speed up the elution of the more polar lycopene band, which is also collected in its own flask. Each of these samples is evaporated to dryness and rehydrated with a minimal amount of dichloromethane.